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Pesti I, Légrádi Á, Farkas E. Primary microglia cell cultures in translational research: Strengths and limitations. J Biotechnol 2024; 386:10-18. [PMID: 38519034 DOI: 10.1016/j.jbiotec.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 03/24/2024]
Abstract
Microglia are the resident macrophages in the central nervous system, accounting for 10-15% of the cell mass in the brain. Next to their physiological role in development, monitoring neuronal function and the maintenance of homeostasis, microglia are crucial in the brain's immune defense. Brain injury and chronic neurological disorders are associated with neuroinflammation, in which microglia activation is a central element. Microglia acquire a wide spectrum of activation states in the diseased or injured brain, some of which are neurotoxic. The investigation of microglia (patho)physiology and therapeutic interventions targeting neuroinflammation is a substantial challenge. In addition to in vivo approaches, the application of in vitro model systems has gained significant ground and is essential to complement in vivo work. Primary microglia cultures have proved to be a useful tool. Microglia cultures have offered the opportunity to explore the mechanistic, molecular elements of microglia activation, the microglia secretome, and the efficacy of therapeutic treatments against neuroinflammation. As all model systems, primary microglia cultures have distinct strengths and limitations to be weighed when experiments are designed and when data are interpreted. Here, we set out to provide a succinct overview of the advantages and pitfalls of the use of microglia cultures, which instructs the refinement and further development of this technique to remain useful in the toolbox of microglia researchers. Since there is no conclusive therapy to combat neurotoxicity linked to neuroinflammation in acute brain injury or neurodegenerative disorders, these research tools remain essential to explore therapeutic opportunities.
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Affiliation(s)
- István Pesti
- Hungarian Centre of Excellence for Molecular Medicine - University of Szeged Cerebral Blood Flow and Metabolism Research Group, Somogyi u 4, Szeged 6720, Hungary; Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary
| | - Ádám Légrádi
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary
| | - Eszter Farkas
- Hungarian Centre of Excellence for Molecular Medicine - University of Szeged Cerebral Blood Flow and Metabolism Research Group, Somogyi u 4, Szeged 6720, Hungary; Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary.
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Chiarini A, Armato U, Gui L, Dal Prà I. "Other Than NLRP3" Inflammasomes: Multiple Roles in Brain Disease. Neuroscientist 2024; 30:23-48. [PMID: 35815856 DOI: 10.1177/10738584221106114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Human neuroinflammatory and neurodegenerative diseases, whose prevalence keeps rising, are still unsolved pathobiological/therapeutical problems. Among others, recent etiology hypotheses stressed as their main driver a chronic neuroinflammation, which is mediated by innate immunity-related protein oligomers: the inflammasomes. A panoply of exogenous and/or endogenous harmful agents activates inflammasomes' assembly, signaling, and IL-1β/IL-18 production and neural cells' pyroptotic death. The underlying concept is that inflammasomes' chronic activation advances neurodegeneration while their short-lasting operation restores tissue homeostasis. Hence, from a therapeutic standpoint, it is crucial to understand inflammasomes' regulatory mechanisms. About this, a deluge of recent studies focused on the NLRP3 inflammasome with suggestions that its pharmacologic block would hinder neurodegeneration. Yet hitherto no evidence proves this view. Moreover, known inflammasomes are numerous, and the mechanisms regulating their expression and function may vary with the involved animal species and strains, as well as organs and cells, and the harmful factors triggered as a result. Therefore, while presently leaving out some little-studied inflammasomes, this review focuses on the "other than NLRP3" inflammasomes that participate in neuroinflammation's complex mechanisms: NLRP1, NLRP2, NLRC4, and AIM2. Although human-specific data about them are relatively scant, we stress that only a holistic view including several human brain inflammasomes and other potential pathogenetic drivers will lead to successful therapies for neuroinflammatory and neurodegenerative diseases.
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Affiliation(s)
- Anna Chiarini
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics, and Gynecology, University of Verona, Verona, Italy
| | - Ubaldo Armato
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics, and Gynecology, University of Verona, Verona, Italy
| | - Li Gui
- Department of Neurology, Southwest Hospital, Chongqing, China
| | - Ilaria Dal Prà
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics, and Gynecology, University of Verona, Verona, Italy
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Dorion MF, Yaqubi M, Senkevich K, Kieran NW, MacDonald A, Chen CXQ, Luo W, Wallis A, Shlaifer I, Hall JA, Dudley RWR, Glass IA, Stratton JA, Fon EA, Bartels T, Antel JP, Gan-or Z, Durcan TM, Healy LM. MerTK is a mediator of alpha-synuclein fibril uptake by human microglia. Brain 2024; 147:427-443. [PMID: 37671615 PMCID: PMC10834256 DOI: 10.1093/brain/awad298] [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: 03/08/2023] [Revised: 07/26/2023] [Accepted: 08/29/2023] [Indexed: 09/07/2023] Open
Abstract
Mer tyrosine kinase (MerTK) is a receptor tyrosine kinase that mediates non-inflammatory, homeostatic phagocytosis of diverse types of cellular debris. Highly expressed on the surface of microglial cells, MerTK is of importance in brain development, homeostasis, plasticity and disease. Yet, involvement of this receptor in the clearance of protein aggregates that accumulate with ageing and in neurodegenerative diseases has yet to be defined. The current study explored the function of MerTK in the microglial uptake of alpha-synuclein fibrils which play a causative role in the pathobiology of synucleinopathies. Using human primary and induced pluripotent stem cell-derived microglia, the MerTK-dependence of alpha-synuclein fibril internalization was investigated in vitro. Relevance of this pathway in synucleinopathies was assessed through burden analysis of MERTK variants and analysis of MerTK expression in patient-derived cells and tissues. Pharmacological inhibition of MerTK and siRNA-mediated MERTK knockdown both caused a decreased rate of alpha-synuclein fibril internalization by human microglia. Consistent with the non-inflammatory nature of MerTK-mediated phagocytosis, alpha-synuclein fibril internalization was not observed to induce secretion of pro-inflammatory cytokines such as IL-6 or TNF, and downmodulated IL-1β secretion from microglia. Burden analysis in two independent patient cohorts revealed a significant association between rare functionally deleterious MERTK variants and Parkinson's disease in one of the cohorts (P = 0.002). Despite a small upregulation in MERTK mRNA expression in nigral microglia from Parkinson's disease/Lewy body dementia patients compared to those from non-neurological control donors in a single-nuclei RNA-sequencing dataset (P = 5.08 × 10-21), no significant upregulation in MerTK protein expression was observed in human cortex and substantia nigra lysates from Lewy body dementia patients compared to controls. Taken together, our findings define a novel role for MerTK in mediating the uptake of alpha-synuclein fibrils by human microglia, with possible involvement in limiting alpha-synuclein spread in synucleinopathies such as Parkinson's disease. Upregulation of this pathway in synucleinopathies could have therapeutic values in enhancing alpha-synuclein fibril clearance in the brain.
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Affiliation(s)
- Marie-France Dorion
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Moein Yaqubi
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Konstantin Senkevich
- McGill Parkinson Program and Neurodegenerative Diseases Group, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Human Genetics, McGill University, Montreal H3A 0C7, Canada
| | - Nicholas W Kieran
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Adam MacDonald
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Carol X Q Chen
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Wen Luo
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Amber Wallis
- UK Dementia Research Institute, University College London, London WC1E 6BT, UK
| | - Irina Shlaifer
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Jeffery A Hall
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Roy W R Dudley
- Department of Pediatric Surgery, Division of Neurosurgery, Montreal Children's Hospital, McGill University Health Centers, Montreal H4A 3J1, Canada
| | - Ian A Glass
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | | | - Jo Anne Stratton
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Edward A Fon
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- McGill Parkinson Program and Neurodegenerative Diseases Group, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Tim Bartels
- UK Dementia Research Institute, University College London, London WC1E 6BT, UK
| | - Jack P Antel
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Ziv Gan-or
- McGill Parkinson Program and Neurodegenerative Diseases Group, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Human Genetics, McGill University, Montreal H3A 0C7, Canada
| | - Thomas M Durcan
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
| | - Luke M Healy
- Neuroimmunology Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal H3A 2B4, Canada
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Yaqubi M, Groh AMR, Dorion MF, Afanasiev E, Luo JXX, Hashemi H, Sinha S, Kieran NW, Blain M, Cui QL, Biernaskie J, Srour M, Dudley R, Hall JA, Sonnen JA, Arbour N, Prat A, Stratton JA, Antel J, Healy LM. Analysis of the microglia transcriptome across the human lifespan using single cell RNA sequencing. J Neuroinflammation 2023; 20:132. [PMID: 37254100 DOI: 10.1186/s12974-023-02809-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 05/17/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND Microglia are tissue resident macrophages with a wide range of critically important functions in central nervous system development and homeostasis. METHOD In this study, we aimed to characterize the transcriptional landscape of ex vivo human microglia across different developmental ages using cells derived from pre-natal, pediatric, adolescent, and adult brain samples. We further confirmed our transcriptional observations using ELISA and RNAscope. RESULTS We showed that pre-natal microglia have a distinct transcriptional and regulatory signature relative to their post-natal counterparts that includes an upregulation of phagocytic pathways. We confirmed upregulation of CD36, a positive regulator of phagocytosis, in pre-natal samples compared to adult samples in situ. Moreover, we showed adult microglia have more pro-inflammatory signature compared to microglia from other developmental ages. We indicated that adult microglia are more immune responsive by secreting increased levels of pro-inflammatory cytokines in response to LPS treatment compared to the pre-natal microglia. We further validated in situ up-regulation of IL18 and CXCR4 in human adult brain section compared to the pre-natal brain section. Finally, trajectory analysis indicated that the transcriptional signatures adopted by microglia throughout development are in response to a changing brain microenvironment and do not reflect predetermined developmental states. CONCLUSION In all, this study provides unique insight into the development of human microglia and a useful reference for understanding microglial contribution to developmental and age-related human disease.
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Affiliation(s)
- Moein Yaqubi
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Adam M R Groh
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Marie-France Dorion
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Elia Afanasiev
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Julia Xiao Xuan Luo
- Department of Microbiology and Immunology, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Hadi Hashemi
- Department of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Fars, Iran
| | - Sarthak Sinha
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
| | - Nicholas W Kieran
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Manon Blain
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Qiao-Ling Cui
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Jeff Biernaskie
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
| | - Myriam Srour
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
- Department of Pediatric Neurosurgery, Montreal Children's Hospital, Montreal, QC, Canada
| | - Roy Dudley
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
- Department of Pediatric Neurosurgery, Montreal Children's Hospital, Montreal, QC, Canada
| | - Jeffery A Hall
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Joshua A Sonnen
- Departments of Pathology, Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Nathalie Arbour
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de L, Université de Montréal (CRCHUM), Montreal, QC, Canada
- Department of Neurosciences, Université de Montréal, Montreal, QC, Canada
| | - Alexandre Prat
- Department of Neurosciences, Université de Montréal, Montreal, QC, Canada
| | - Jo Anne Stratton
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Jack Antel
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Luke M Healy
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada.
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5
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Dorion MF, Yaqubi M, Murdoch HJ, Hall JA, Dudley R, Antel JP, Durcan TM, Healy LM. Systematic comparison of culture media uncovers phenotypic shift of primary human microglia defined by reduced reliance to CSF1R signaling. Glia 2023; 71:1278-1293. [PMID: 36680780 DOI: 10.1002/glia.24338] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/17/2022] [Accepted: 01/02/2023] [Indexed: 01/22/2023]
Abstract
Efforts to understand microglia function in health and diseases have been hindered by the lack of culture models that recapitulate in situ cellular properties. In recent years, the use of serum-free media with brain-derived growth factors (colony stimulating factor 1 receptor [CSF1R] ligands and TGF-β1/2) have been favored for the maintenance of rodent microglia as they promote morphological features observed in situ. Here we study the functional and transcriptomic impacts of such media on human microglia (hMGL). Media formulation had little impact on microglia transcriptome assessed by RNA sequencing which was sufficient to significantly alter microglia capacity to phagocytose myelin debris and to elicit an inflammatory response to lipopolysaccharide. When compared to immediately ex vivo microglia from the same donors, the addition of fetal bovine serum to culture media, but not growth factors, was found to aid in the maintenance of key signature genes including those involved in phagocytic processes. A phenotypic shift characterized by CSF1R downregulation in culture correlated with a lack of reliance on CSF1R signaling for survival. Consequently, no improvement in cell survival was observed following culture supplementation with CSF1R ligands. Our study provides better understanding of hMGL in culture, with observations that diverge from those previously made in rodent microglia.
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Affiliation(s)
- Marie-France Dorion
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Moein Yaqubi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Hunter J Murdoch
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Jeffery A Hall
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Roy Dudley
- Department of Pediatric Neurosurgery, Montreal Children's Hospital, Montreal, Canada
| | - Jack P Antel
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Thomas Martin Durcan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Luke Michael Healy
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Québec, Canada
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6
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Davé VA, Klein RS. The multitaskers of the brain: Glial responses to viral infections and associated post-infectious neurologic sequelae. Glia 2023; 71:803-818. [PMID: 36334073 PMCID: PMC9931640 DOI: 10.1002/glia.24294] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 11/08/2022]
Abstract
Many viral infections cause acute and chronic neurologic diseases which can lead to degeneration of cortical functions. While neurotropic viruses that gain access to the central nervous system (CNS) may induce brain injury directly via infection of neurons or their supporting cells, they also alter brain function via indirect neuroimmune mechanisms that may disrupt the blood-brain barrier (BBB), eliminate synapses, and generate neurotoxic astrocytes and microglia that prevent recovery of neuronal circuits. Non-neuroinvasive, neurovirulent viruses may also trigger aberrant responses in glial cells, including those that interfere with motor and sensory behaviors, encoding of memories and executive function. Increasing evidence from human and animal studies indicate that neuroprotective antiviral responses that amplify levels of innate immune molecules dysregulate normal neuroimmune processes, even in the absence of neuroinvasion, which may persist after virus is cleared. In this review, we discuss how select emerging and re-emerging RNA viruses induce neuroimmunologic responses that lead to dysfunction of higher order processes including visuospatial recognition, learning and memory, and motor control. Identifying therapeutic targets that return the neuroimmune system to homeostasis is critical for preventing virus-induced neurodegenerative disorders.
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Affiliation(s)
- Veronica A Davé
- Center for Neuroimmunology & Neuroinfectious Diseases, Departments of Medicine, Pathology & Immunology, Neurosciences, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Robyn S Klein
- Center for Neuroimmunology & Neuroinfectious Diseases, Departments of Medicine, Pathology & Immunology, Neurosciences, Washington University School of Medicine, St. Louis, Missouri, USA
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7
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Lau V, Ramer L, Tremblay MÈ. An aging, pathology burden, and glial senescence build-up hypothesis for late onset Alzheimer's disease. Nat Commun 2023; 14:1670. [PMID: 36966157 PMCID: PMC10039917 DOI: 10.1038/s41467-023-37304-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 03/07/2023] [Indexed: 03/27/2023] Open
Abstract
Alzheimer's disease (AD) predominantly occurs as a late onset (LOAD) form involving neurodegeneration and cognitive decline with progressive memory loss. Risk factors that include aging promote accumulation of AD pathologies, such as amyloid-beta and tau aggregates, as well as inflammation and oxidative stress. Homeostatic glial states regulate and suppress pathology buildup; inflammatory states exacerbate pathology by releasing pro-inflammatory cytokines. Multiple stresses likely induce glial senescence, which could decrease supportive functions and reinforce inflammation. In this perspective, we hypothesize that aging first drives AD pathology burden, whereafter AD pathology putatively induces glial senescence in LOAD. We hypothesize that increasing glial senescence, particularly local senescent microglia accumulation, sustains and drives perpetuating buildup and spread of AD pathologies, glial aging, and further senescence. We predict that increasing glial senescence, particularly local senescent microglia accumulation, also transitions individuals from healthy cognition into mild cognitive impairment and LOAD diagnosis. These pathophysiological underpinnings may centrally contribute to LOAD onset, but require further mechanistic investigation.
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Affiliation(s)
- Victor Lau
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Institute on Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
| | - Leanne Ramer
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Institute on Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada.
- The Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
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Chiarini A, Gui L, Viviani C, Armato U, Dal Prà I. NLRP3 Inflammasome’s Activation in Acute and Chronic Brain Diseases—An Update on Pathogenetic Mechanisms and Therapeutic Perspectives with Respect to Other Inflammasomes. Biomedicines 2023; 11:biomedicines11040999. [PMID: 37189617 DOI: 10.3390/biomedicines11040999] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 03/29/2023] Open
Abstract
Increasingly prevalent acute and chronic human brain diseases are scourges for the elderly. Besides the lack of therapies, these ailments share a neuroinflammation that is triggered/sustained by different innate immunity-related protein oligomers called inflammasomes. Relevant neuroinflammation players such as microglia/monocytes typically exhibit a strong NLRP3 inflammasome activation. Hence the idea that NLRP3 suppression might solve neurodegenerative ailments. Here we review the recent Literature about this topic. First, we update conditions and mechanisms, including RNAs, extracellular vesicles/exosomes, endogenous compounds, and ethnic/pharmacological agents/extracts regulating NLRP3 function. Second, we pinpoint NLRP3-activating mechanisms and known NLRP3 inhibition effects in acute (ischemia, stroke, hemorrhage), chronic (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, MS, ALS), and virus-induced (Zika, SARS-CoV-2, and others) human brain diseases. The available data show that (i) disease-specific divergent mechanisms activate the (mainly animal) brains NLRP3; (ii) no evidence proves that NLRP3 inhibition modifies human brain diseases (yet ad hoc trials are ongoing); and (iii) no findings exclude that concurrently activated other-than-NLRP3 inflammasomes might functionally replace the inhibited NLRP3. Finally, we highlight that among the causes of the persistent lack of therapies are the species difference problem in disease models and a preference for symptomatic over etiologic therapeutic approaches. Therefore, we posit that human neural cell-based disease models could drive etiological, pathogenetic, and therapeutic advances, including NLRP3’s and other inflammasomes’ regulation, while minimizing failure risks in candidate drug trials.
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9
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Tang YM, Pulimood NS, Stifani S. Comparing the Characteristics of Microglia Preparations Generated Using Different Human iPSC-Based Differentiation Methods to Model Neurodegenerative Diseases. ASN Neuro 2022; 14:17590914221145105. [PMID: 36524236 PMCID: PMC9761225 DOI: 10.1177/17590914221145105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
As the resident immune cells of the healthy nervous system, homeostatic microglia can rapidly become activated in response to injury/disease. Dysregulated microglia activation is a hallmark of nervous system disorders including neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. The elucidation of the biological and pathological roles of microglia has recently benefitted from the development of microglia-like cells using human induced pluripotent stem cell (iPSC)-based approaches. The success of iPSC-derived microglia preparations as a disease-relevant model system depends on their representation of the in vivo spatial and temporal heterogeneity of microglia under pathological conditions. Little is currently known about the potential of human iPSC-derived microglia generated using different methods for the study of neurodegenerative diseases. We compared the transcriptomes of human iPSC-derived microglia generated using two frequently used in vitro differentiation methods to determine whether separate strategies can generate microglia with distinct transcriptional signatures in vitro. We show that microglia derived using different differentiation methods display distinct maturation characteristics after equivalent times in culture. We also reveal that iPSC-derived microglia preparations generated using these two methods are composed of different subpopulations with transcriptomic signatures resembling those of in vivo regionally distinct microglia subtypes, specifically white-matter and gray-matter microglia. These findings highlight the need to better characterize the subtype composition of each microglia preparation prior to its use to model neurodegenerative diseases.
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Affiliation(s)
- Ye Man Tang
- Department of Neurology and Neurosurgery, Montreal Neurological
Institute-Hospital, McGill
University, Montreal, Quebec, Canada
| | - Nisha S. Pulimood
- Department of Neurology and Neurosurgery, Montreal Neurological
Institute-Hospital, McGill
University, Montreal, Quebec, Canada
| | - Stefano Stifani
- Department of Neurology and Neurosurgery, Montreal Neurological
Institute-Hospital, McGill
University, Montreal, Quebec, Canada,Stefano Stifani, Department of Neurology
and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University,
Montreal, Quebec, Canada H3A 2B4.
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10
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Li ZQ, Li TX, Tian M, Ren ZS, Yuan CY, Yang RK, Shi SJ, Li H, Kou ZZ. Glial cells and neurologic autoimmune disorders. Front Cell Neurosci 2022; 16:1028653. [PMID: 36385950 PMCID: PMC9644207 DOI: 10.3389/fncel.2022.1028653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/03/2022] [Indexed: 12/01/2023] Open
Abstract
Neurologic autoimmune disorders affect people's physical and mental health seriously. Glial cells, as an important part of the nervous system, play a vital role in the occurrence of neurologic autoimmune disorders. Glial cells can be hyperactivated in the presence of autoantibodies or pathological changes, to influence neurologic autoimmune disorders. This review is mainly focused on the roles of glial cells in neurologic autoimmune disorders and the influence of autoantibodies produced by autoimmune disorders on glial cells. We speculate that the possibility of glial cells might be a novel way for the investigation and therapy of neurologic autoimmune disorders.
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Affiliation(s)
| | | | | | | | | | | | | | - Hui Li
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi’an, China
| | - Zhen-Zhen Kou
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi’an, China
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11
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Tiedt S, Buchan AM, Dichgans M, Lizasoain I, Moro MA, Lo EH. The neurovascular unit and systemic biology in stroke - implications for translation and treatment. Nat Rev Neurol 2022; 18:597-612. [PMID: 36085420 DOI: 10.1038/s41582-022-00703-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2022] [Indexed: 12/24/2022]
Abstract
Ischaemic stroke is a leading cause of disability and death for which no acute treatments exist beyond recanalization. The development of novel therapies has been repeatedly hindered by translational failures that have changed the way we think about tissue damage after stroke. What was initially a neuron-centric view has been replaced with the concept of the neurovascular unit (NVU), which encompasses neuronal, glial and vascular compartments, and the biphasic nature of neural-glial-vascular signalling. However, it is now clear that the brain is not the private niche it was traditionally thought to be and that the NVU interacts bidirectionally with systemic biology, such as systemic metabolism, the peripheral immune system and the gut microbiota. Furthermore, these interactions are profoundly modified by internal and external factors, such as ageing, temperature and day-night cycles. In this Review, we propose an extension of the concept of the NVU to include its dynamic interactions with systemic biology. We anticipate that this integrated view will lead to the identification of novel mechanisms of stroke pathophysiology, potentially explain previous translational failures, and improve stroke care by identifying new biomarkers of and treatment targets in stroke.
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Affiliation(s)
- Steffen Tiedt
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA), . .,Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Alastair M Buchan
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA).,Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Martin Dichgans
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA).,Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Ignacio Lizasoain
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA).,Department of Pharmacology and Toxicology, Complutense Medical School, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain
| | - Maria A Moro
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA).,Centro Nacional de Investigaciones Cardiovasculares, CNIC, Madrid, Spain
| | - Eng H Lo
- Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA), . .,Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. .,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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12
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Integration of Genetic and Immune Infiltration Insights into Data Mining of Multiple Sclerosis Pathogenesis. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2022; 2022:1661334. [PMID: 35795733 PMCID: PMC9252675 DOI: 10.1155/2022/1661334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022]
Abstract
Background Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system. MS pathogenesis is closely related to the environment, genetic, and immune system, but the underlying interactions have not been clearly elucidated. This study aims to unveil the genetic basis and immune landscape of MS pathogenesis with bioinformatics. Methods Gene matrix was retrieved from the gene expression database NCBI-GEO. Then, bioinformatics was used to standardize the samples and obtain differentially expressed genes (DEGs). The protein-protein interaction network was constructed with DEGs on the STRING website. Cytohubba plug-in and MCODE plug-in were used to mine hub genes. Meanwhile, the CIBERSORTX algorithm was used to explore the characteristics of immune cell infiltration in MS brain tissues. Spearman correlation analysis was performed between genes and immune cells, and the correlation between genes and different types of brain tissues was also analyzed using the WGCNA method. Results A total of 90 samples from 2 datasets were included, and 882 DEGs and 10 hub genes closely related to MS were extracted. Functional enrichment analysis suggested the role of immune response in MS. Besides, CIBERSORTX algorithm results showed that MS brain tissues contained a variety of infiltrating immune cells. Correlation analysis suggested that the hub genes were highly relevant to chronic active white matter lesions. Certain hub genes played a role in the activation of immune cells such as macrophages and natural killer cells. Conclusions Our study shall provide guidance for the further study of the genetic basis and immune infiltration mechanism of MS.
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13
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Immune Mechanism of Epileptogenesis and Related Therapeutic Strategies. Biomedicines 2022; 10:biomedicines10030716. [PMID: 35327518 PMCID: PMC8945207 DOI: 10.3390/biomedicines10030716] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/05/2023] Open
Abstract
Immunologic and neuroinflammatory pathways have been found to play a major role in the pathogenesis of many neurological disorders such as epilepsy, proposing the use of novel therapeutic strategies. In the era of personalized medicine and in the face of the exhaustion of anti-seizure therapeutic resources, it is worth looking at the current or future possibilities that neuroimmunomodulator or anti-inflammatory therapy can offer us in the management of patients with epilepsy. For this reason, we performed a narrative review on the recent advances on the basic epileptogenic mechanisms related to the activation of immunity or neuroinflammation with special attention to current and future opportunities for novel treatments in epilepsy. Neuroinflammation can be considered a universal phenomenon and occurs in structural, infectious, post-traumatic, autoimmune, or even genetically based epilepsies. The emerging research developed in recent years has allowed us to identify the main molecular pathways involved in these processes. These molecular pathways could constitute future therapeutic targets for epilepsy. Different drugs current or in development have demonstrated their capacity to inhibit or modulate molecular pathways involved in the immunologic or neuroinflammatory mechanisms described in epilepsy. Some of them should be tested in the future as possible antiepileptic drugs.
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14
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IL-1 reprogramming of adult neural stem cells limits neurocognitive recovery after viral encephalitis by maintaining a proinflammatory state. Brain Behav Immun 2022; 99:383-396. [PMID: 34695572 DOI: 10.1016/j.bbi.2021.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 02/07/2023] Open
Abstract
Innate immune responses to emerging RNA viruses are increasingly recognized as having significant contributions to neurologic sequelae, especially memory disorders. Using a recovery model of West Nile virus (WNV) encephalitis, we show that, while macrophages deliver the antiviral and anti-neurogenic cytokine IL-1β during acute infection; viral recovery is associated with continued astrocyte inflammasome-mediated production of inflammatory levels of IL-1β, which is maintained by hippocampal astrogenesis via IL-1R1 signaling in neural stem cells (NSC). Accordingly, aberrant astrogenesis is prevented in the absence of IL-1 signaling in NSC, indicating that only newly generated astrocytes exert neurotoxic effects, preventing synapse repair and promoting spatial learning deficits. Ex vivo evaluation of IL-1β-treated adult hippocampal NSC revealed the upregulation of developmental differentiation pathways that derail adult neurogenesis in favor of astrogenesis, following viral infection. We conclude that NSC-specific IL-1 signaling within the hippocampus during viral encephalitis prevents synapse recovery and promotes spatial learning defects via altered fates of NSC progeny that maintain inflammation.
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15
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Wu F, Liu Z, Li G, Zhou L, Huang K, Wu Z, Zhan R, Shen J. Inflammation and Oxidative Stress: Potential Targets for Improving Prognosis After Subarachnoid Hemorrhage. Front Cell Neurosci 2021; 15:739506. [PMID: 34630043 PMCID: PMC8497759 DOI: 10.3389/fncel.2021.739506] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/20/2021] [Indexed: 12/13/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) has a high mortality rate and causes long-term disability in many patients, often associated with cognitive impairment. However, the pathogenesis of delayed brain dysfunction after SAH is not fully understood. A growing body of evidence suggests that neuroinflammation and oxidative stress play a negative role in neurofunctional deficits. Red blood cells and hemoglobin, immune cells, proinflammatory cytokines, and peroxidases are directly or indirectly involved in the regulation of neuroinflammation and oxidative stress in the central nervous system after SAH. This review explores the role of various cellular and acellular components in secondary inflammation and oxidative stress after SAH, and aims to provide new ideas for clinical treatment to improve the prognosis of SAH.
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Affiliation(s)
- Fan Wu
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zongchi Liu
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Ganglei Li
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Lihui Zhou
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Kaiyuan Huang
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zhanxiong Wu
- College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, China
| | - Renya Zhan
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jian Shen
- First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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16
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Neuroinflammation: An Integrating Overview of Reactive-Neuroimmune Cell Interactions in Health and Disease. Mediators Inflamm 2021; 2021:9999146. [PMID: 34158806 PMCID: PMC8187052 DOI: 10.1155/2021/9999146] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 05/04/2021] [Indexed: 12/14/2022] Open
Abstract
The concept of central nervous system (CNS) inflammation has evolved over the last decades. Neuroinflammation is the response of reactive CNS components to altered homeostasis, regardless of the cause to be endogenous or exogenous. Neurological diseases, whether traumatic, neoplastic, ischemic, metabolic, toxic, infectious, autoimmune, developmental, or degenerative, involve direct and indirect immune-related neuroinflammation. Brain infiltrates of the innate and adaptive immune system cells appear in response to an infective or otherwise noxious agent and produce inflammatory mediators. Mediators of inflammation include local and recruited cells and signals. Processes derived from extrinsic and intrinsic CNS diseases also elicit the CNS inflammatory response. A deeper understanding of immune-related inflammation in health and disease is necessary to find potential therapeutic targets for preventing or reducing CNS damage. This review is aimed at discussing the innate and adaptive immune system functions and their roles in regulating brain cell responses in disease and homeostasis maintenance.
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17
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Danger-Sensing/Patten Recognition Receptors and Neuroinflammation in Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21239036. [PMID: 33261147 PMCID: PMC7731137 DOI: 10.3390/ijms21239036] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
Fibrillar aggregates and soluble oligomers of both Amyloid-β peptides (Aβs) and hyperphosphorylated Tau proteins (p-Tau-es), as well as a chronic neuroinflammation are the main drivers causing progressive neuronal losses and dementia in Alzheimer’s disease (AD). However, the underlying pathogenetic mechanisms are still much disputed. Several endogenous neurotoxic ligands, including Aβs, and/or p-Tau-es activate innate immunity-related danger-sensing/pattern recognition receptors (PPRs) thereby advancing AD’s neuroinflammation and progression. The major PRR families involved include scavenger, Toll-like, NOD-like, AIM2-like, RIG-like, and CLEC-2 receptors, plus the calcium-sensing receptor (CaSR). This quite intricate picture stresses the need to identify the pathogenetically topmost Aβ-activated PRR, whose signaling would trigger AD’s three main drivers and their intra-brain spread. In theory, the candidate might belong to any PRR family. However, results of preclinical studies using in vitro nontumorigenic human cortical neurons and astrocytes and in vivo AD-model animals have started converging on the CaSR as the pathogenetically upmost PRR candidate. In fact, the CaSR binds both Ca2+ and Aβs and promotes the spread of both Ca2+ dyshomeostasis and AD’s three main drivers, causing a progressive neurons’ death. Since CaSR’s negative allosteric modulators block all these effects, CaSR’s candidacy for topmost pathogenetic PRR has assumed a growing therapeutic potential worth clinical testing.
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18
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Zia S, Rawji KS, Michaels NJ, Burr M, Kerr BJ, Healy LM, Plemel JR. Microglia Diversity in Health and Multiple Sclerosis. Front Immunol 2020; 11:588021. [PMID: 33240276 PMCID: PMC7677361 DOI: 10.3389/fimmu.2020.588021] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/14/2020] [Indexed: 12/11/2022] Open
Abstract
Multiple Sclerosis (MS) is a neurodegenerative disease characterized by multiple focal lesions, ongoing demyelination and, for most people, a lack of remyelination. MS lesions are enriched with monocyte-derived macrophages and brain-resident microglia that, together, are likely responsible for much of the immune-mediated neurotoxicity. However, microglia and macrophage also have documented neuroprotective and regenerative roles, suggesting a potential diversity in their functions. Linked with microglial functional diversity, they take on diverse phenotypes developmentally, regionally and across disease conditions. Advances in technologies such as single-cell RNA sequencing and mass cytometry of immune cells has led to dramatic developments in understanding the phenotypic changes of microglia and macrophages. This review highlights the origins of microglia, their heterogeneity throughout normal ageing and their contribution to pathology and repair, with a specific focus on autoimmunity and MS. As phenotype dictates function, the emerging heterogeneity of microglia and macrophage populations in MS offers new insights into the potential immune mechanisms that result in inflammation and regeneration.
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Affiliation(s)
- Sameera Zia
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Khalil S Rawji
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Campus, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom
| | - Nathan J Michaels
- Ministry of Health, British Columbia Government, Victoria, BC, Canada
| | - Mena Burr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Luke M Healy
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Jason R Plemel
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.,Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB, Canada
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19
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Hanger B, Couch A, Rajendran L, Srivastava DP, Vernon AC. Emerging Developments in Human Induced Pluripotent Stem Cell-Derived Microglia: Implications for Modelling Psychiatric Disorders With a Neurodevelopmental Origin. Front Psychiatry 2020; 11:789. [PMID: 32848951 PMCID: PMC7433763 DOI: 10.3389/fpsyt.2020.00789] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
Microglia, the resident tissue macrophages of the brain, are increasingly implicated in the pathophysiology of psychiatric disorders with a neurodevelopmental origin, including schizophrenia. To date, however, our understanding of the potential role for these cells in schizophrenia has been informed by studies of aged post-mortem samples, low resolution in vivo neuroimaging and rodent models. Whilst these have provided important insights, including signs of the heterogeneous nature of microglia, we currently lack a validated human in vitro system to characterize microglia in the context of brain health and disease during neurodevelopment. Primarily, this reflects a lack of access to human primary tissue during developmental stages. In this review, we first describe microglia, including their ontogeny and heterogeneity and consider their role in brain development. We then provide an evaluation of the potential for differentiating microglia from human induced pluripotent stem cells (hiPSCs) as a robust in vitro human model system to study these cells. We find the majority of protocols for hiPSC-derived microglia generate cells characteristically similar to foetal stage microglia when exposed to neuronal environment-like cues. This may represent a robust and relevant model for the study of cellular and molecular mechanisms in schizophrenia. Each protocol however, provides unique benefits as well as shortcomings, highlighting the need for context-dependent protocol choice and cross-lab collaboration and communication to identify the most robust and translatable microglia model.
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Affiliation(s)
- Bjørn Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
| | - Amalie Couch
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
| | - Lawrence Rajendran
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- UK Dementia Research Institute, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Deepak P. Srivastava
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Anthony C. Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
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20
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Harry GJ, Childers G, Giridharan S, Hernandes IL. An association between mitochondria and microglia effector function. What do we think we know? NEUROIMMUNOLOGY AND NEUROINFLAMMATION 2020; 7:150-165. [PMID: 32934971 PMCID: PMC7489447 DOI: 10.20517/2347-8659.2020.07] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While resident innate immune cells of the central nervous system, the microglia, represent a cell population unique in origin, microenvironment, and longevity, they assume many properties displayed by peripheral macrophages. One prominent shared property is the ability to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS) upon activation by the pro-inflammatory stimuli lipopolysaccharide. This shift serves to meet specific cellular demands and allows for cell survival, similar to the Warburg effect demonstrated in cancer cells. In contrast, normal survelliance phenotype or stimulation to a non-proinflammatory phenotype relies primarily on OXPHOS and fatty acid oxidation. Thus, mitochondria appear to function as a pivotal signaling platform linking energy metabolism and macrophage polarization upon activation. These unique shifts in cell bioenergetics in response to different stimuli are essential for proper effector responses at sites of infection, inflammation, or injury. Here we present a summary of recent developments as to how these dynamics characterized in peripheral macrophages are displayed in microglia. The new insights provided by an increased understanding of metabolic reprogramming in macrophages may allow for translation to the CNS and a better understanding of microglia heterogeneity, regulation, and function.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
| | - Gabrielle Childers
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
- Current affiliation: Gabrielle Childers, University of Alabama, Birmingham, AL
| | - Sahana Giridharan
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
- Giridharan, Duke University, Durham, NC
| | - Irisyunuel Lopez Hernandes
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
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21
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Morales I, Sanchez A, Puertas-Avendaño R, Rodriguez-Sabate C, Perez-Barreto A, Rodriguez M. Neuroglial transmitophagy and Parkinson's disease. Glia 2020; 68:2277-2299. [PMID: 32415886 DOI: 10.1002/glia.23839] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/28/2022]
Abstract
Mitophagy is essential for the health of dopaminergic neurons because mitochondrial damage is a keystone of Parkinson's disease. The aim of the present work was to study the degradation of mitochondria in the degenerating dopaminergic synapse. Adult Sprague-Dawley rats and YFP-Mito-DAn mice with fluorescent mitochondria in dopaminergic neurons were injected in the lateral ventricles with 6-hydroxydopamine, a toxic that inhibits the mitochondrial chain of dopaminergic neurons and blockades the axonal transport. Dopaminergic terminals closest to the lateral ventricle showed an axonal fragmentation and an accumulation of damaged mitochondria in 2-9 μ saccular structures (spheroids). Damaged mitochondria accumulated in spheroids initiated (showing high Pink1, parkin, ubiquitin, p-S65-Ubi, AMBRA1, and BCL2L13 immunoreactivity and developing autophagosomes) but did not complete (mitochondria were not polyubiquitinated, autophagosomes had no STX17, and no lysosomes were found in spheroids) the mitophagy process. Then, spheroids were penetrated by astrocytic processes and DAergic mitochondria were transferred to astrocytes where they were polyubiquitinated (UbiK63+) and linked to mature autophagosomes (STX17+) which became autophagolysosomes (Lamp1/Lamp2 which co-localized with LC3). Present data provide evidence that the mitophagy of degenerating dopaminergic terminals starts in the dopaminergic spheroids and finishes in the surrounding astrocytes (spheroid-mediated transmitophagy). The neuron-astrocyte transmitophagy could be critical for preventing the release of damaged mitochondria to the extracellular medium and the neuro-inflammatory activity which characterizes Parkinson's disease.
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Affiliation(s)
- Ingrid Morales
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain.,Center for Networked Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
| | - Alberto Sanchez
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | - Ricardo Puertas-Avendaño
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | | | - Adrian Perez-Barreto
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | - Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain.,Center for Networked Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
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22
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Guerrero BL, Sicotte NL. Microglia in Multiple Sclerosis: Friend or Foe? Front Immunol 2020; 11:374. [PMID: 32265902 PMCID: PMC7098953 DOI: 10.3389/fimmu.2020.00374] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Microglia originate from myeloid progenitors in the embryonic yolk sac and play an integral role in central nervous system (CNS) development, immune surveillance and repair. The role of microglia in multiple sclerosis (MS) has been complex and controversial, with evidence suggesting that these cells play key roles in both active inflammation and remyelination. Here we will review the most recent histological classification of MS lesions as well as the evidence supporting both inflammatory and reparative functions of these cells. We will also review how microglia may yield new biomarkers for MS activity and serve as a potential target for therapy.
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Affiliation(s)
- Brooke L Guerrero
- Multiple Sclerosis and Neuroimmunology Program, Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Nancy L Sicotte
- Multiple Sclerosis and Neuroimmunology Program, Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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