201
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Lee JW, Lee IH, Iimura T, Kong SW. Two macrophages, osteoclasts and microglia: from development to pleiotropy. Bone Res 2021; 9:11. [PMID: 33568650 PMCID: PMC7875961 DOI: 10.1038/s41413-020-00134-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 12/11/2022] Open
Abstract
Tissue-resident macrophages are highly specialized to their tissue-specific microenvironments, activated by various inflammatory signals and modulated by genetic and environmental factors. Osteoclasts and microglia are distinct tissue-resident cells of the macrophage lineage in bone and brain that are responsible for pathological changes in osteoporosis and Alzheimer’s disease (AD), respectively. Osteoporosis is more frequently observed in individuals with AD compared to the prevalence in general population. Diagnosis of AD is often delayed until underlying pathophysiological changes progress and cause irreversible damages in structure and function of brain. As such earlier diagnosis and intervention of individuals at higher risk would be indispensable to modify clinical courses. Pleiotropy is the phenomenon that a genetic variant affects multiple traits and the genetic correlation between two traits could suggest a shared molecular mechanism. In this review, we discuss that the Pyk2-mediated actin polymerization pathway in osteoclasts and microglia in bone and brain, respectively, is the horizontal pleiotropic mediator of shared risk factors for osteoporosis and AD.
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Affiliation(s)
- Ji-Won Lee
- Department of Nephrology, Transplant Research Program, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Pharmacology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, 060-8586, Japan
| | - In-Hee Lee
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Tadahiro Iimura
- Department of Pharmacology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, 060-8586, Japan
| | - Sek Won Kong
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA, 02115, USA. .,Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
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202
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Prinz M, Masuda T, Wheeler MA, Quintana FJ. Microglia and Central Nervous System-Associated Macrophages-From Origin to Disease Modulation. Annu Rev Immunol 2021; 39:251-277. [PMID: 33556248 DOI: 10.1146/annurev-immunol-093019-110159] [Citation(s) in RCA: 235] [Impact Index Per Article: 78.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The immune system of the central nervous system (CNS) consists primarily of innate immune cells. These are highly specialized macrophages found either in the parenchyma, called microglia, or at the CNS interfaces, such as leptomeningeal, perivascular, and choroid plexus macrophages. While they were primarily thought of as phagocytes, their function extends well beyond simple removal of cell debris during development and diseases. Brain-resident innate immune cells were found to be plastic, long-lived, and host to an outstanding number of risk genes for multiple pathologies. As a result, they are now considered the most suitable targets for modulating CNS diseases. Additionally, recent single-cell technologies enhanced our molecular understanding of their origins, fates, interactomes, and functional cell statesduring health and perturbation. Here, we review the current state of our understanding and challenges of the myeloid cell biology in the CNS and treatment options for related diseases.
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Affiliation(s)
- Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, D-79106 Freiburg, Germany; .,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, D-79106 Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies and Centre for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, D-79104 Freiburg, Germany
| | - Takahiro Masuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 812-8582 Fukuoka, Japan;
| | - Michael A Wheeler
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA; , .,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA; , .,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
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203
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Srimat Kandadai K, Kotur MB, Dokalis N, Amrein I, Keller CW, Münz C, Wolfer D, Prinz M, Lünemann JD. ATG5 in microglia does not contribute vitally to autoimmune neuroinflammation in mice. Autophagy 2021; 17:3566-3576. [PMID: 33522362 DOI: 10.1080/15548627.2021.1883880] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Microglia, resident myeloid immune cells of the central nervous system (CNS), actively shape the circuitry of the brain, maintain CNS homeostasis during the steady state and orchestrate immune responses upon CNS injury. Both canonical and non-canonical functions of the macroautophagy/autophagy-related protein ATG5 regulate myeloid cell survival and immune responses. Here, we report that loss of ATG5 in postnatal microglia does not perturb CNS tissue integrity, microglial cell survival, or immune activation. Learning task performances were unchanged in mutant mice. Furthermore, lack of ATG5 expression in microglia had no impact on the development of experimental autoimmune encephalomyelitis. These data indicate that, basal autophagy, identified to be essential for the survival and function of neuronal cells, is not required to maintain CNS homeostasis if absent in adult microglia and ATG5 expression is dispensable for the development of autoimmune neuroinflammation.Abbreviations Ag, antigen; APC, antigen presenting cell; ATG/Atg, autophagy-related; CD, cluster of differentiation; CNS, central nervous system; DC, dendritic cell; EAE, experimental autoimmune encephalomyelitis; fl, floxed; LAP, LC3-associated phagocytosis; LC3, microtubule-associated protein 1 light chain 3; MFI, median fluorescence intensity; MHCII, major histocompatibility complex class II; MOG, myelin oligodendrocyte glycoprotein; MS, multiple sclerosis.
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Affiliation(s)
- Keertana Srimat Kandadai
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany
| | - Monika B Kotur
- Laboratory of Neuroinflammation, Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - Nikolaos Dokalis
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Irmgard Amrein
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Christian W Keller
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany.,Laboratory of Neuroinflammation, Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - Christian Münz
- Laboratory of Viral Immunobiology, Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - David Wolfer
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Marco Prinz
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, University of Freiburg; Signalling Research Centres BIOSS and CIBSS, University of Freiburg; Center for Basics in NeuroModulation (Neuromodulbasics), University of Freiburg, Germany
| | - Jan D Lünemann
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany.,Laboratory of Neuroinflammation, Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
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204
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Allende ML, Zhu H, Kono M, Hoachlander-Hobby LE, Huso VL, Proia RL. Genetic defects in the sphingolipid degradation pathway and their effects on microglia in neurodegenerative disease. Cell Signal 2021; 78:109879. [PMID: 33296739 PMCID: PMC7775721 DOI: 10.1016/j.cellsig.2020.109879] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 12/15/2022]
Abstract
Sphingolipids, which function as plasma membrane lipids and signaling molecules, are highly enriched in neuronal and myelin membranes in the nervous system. They are degraded in lysosomes by a defined sequence of enzymatic steps. In the related group of disorders, the sphingolipidoses, mutations in the genes that encode the individual degradative enzymes cause lysosomal accumulation of sphingolipids and often result in severe neurodegenerative disease. Here we review the information indicating that microglia, which actively clear sphingolipid-rich membranes in the brain during development and homeostasis, are directly affected by these mutations and promote neurodegeneration in the sphingolipidoses. We also identify parallels between the sphingolipidoses and more common forms of neurodegeneration, which both exhibit evidence of defective sphingolipid clearance in the nervous system.
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Affiliation(s)
- Maria L Allende
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hongling Zhu
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mari Kono
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lila E Hoachlander-Hobby
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vienna L Huso
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA
| | - Richard L Proia
- Genetics of Development and Disease Section, Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 9000 Rockville Pike, National Institutes of Health, Bethesda, MD 20892, USA.
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205
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Abstract
PURPOSE OF REVIEW In multiple sclerosis, currently approved disease-modifying treatments are effective in modulating peripheral immunity, and coherently, in reducing clinical/radiological relapses, but still, they perform poorly in preventing disease progression and overall disability accrual. This review provides an up-to-date overview of the neuropathology of progressive multiple sclerosis, including a summary of the main mechanisms of disease progression. RECENT FINDINGS Clinical progression in multiple sclerosis is likely related to the accumulation of neuro-axonal loss in a lifelong inflammatory CNS environment (both adaptive and innate) and relative un-balance between damage, repair and brain functional reserve. A critical driver appears to be the T-cell and B-cell-mediated compartmentalized inflammation within the leptomeninges and within the parenchyma. Recent perspective highlighted also the role of the glial response to such lifelong inflammatory injury as the critical player for both pathological and clinical outcomes. SUMMARY The neuropathological and biological understanding of disease progression in multiple sclerosis have progressed in the last few years. As a consequence, new therapeutic approaches are emerging outside the modulation of T-cell activity and/or the depletion of B cells.
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206
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The aging mouse brain: cognition, connectivity and calcium. Cell Calcium 2021; 94:102358. [PMID: 33517250 DOI: 10.1016/j.ceca.2021.102358] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 02/08/2023]
Abstract
Aging is a complex process that differentially impacts multiple cognitive, sensory, neuronal and molecular processes. Technological innovations now allow for parallel investigation of neuronal circuit function, structure and molecular composition in the brain of awake behaving adult mice. Thus, mice have become a critical tool to better understand how aging impacts the brain. However, a more granular systems-based approach, which considers the impact of age on key features relating to neural processing, is required. Here, we review evidence probing the impact of age on the mouse brain. We focus on a range of processes relating to neuronal function, including cognitive abilities, sensory systems, synaptic plasticity and calcium regulation. Across many systems, we find evidence for prominent age-related dysregulation even before 12 months of age, suggesting that emerging age-related alterations can manifest by late adulthood. However, we also find reports suggesting that some processes are remarkably resilient to aging. The evidence suggests that aging does not drive a parallel, linear dysregulation of all systems, but instead impacts some processes earlier, and more severely, than others. We propose that capturing the more fine-scale emerging features of age-related vulnerability and resilience may provide better opportunities for the rejuvenation of the aged brain.
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207
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Changing Functional Signatures of Microglia along the Axis of Brain Aging. Int J Mol Sci 2021; 22:ijms22031091. [PMID: 33499206 PMCID: PMC7865559 DOI: 10.3390/ijms22031091] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Microglia, the innate immune cells of the brain, are commonly perceived as resident macrophages of the central nervous system (CNS). This definition, however, requires further specification, as under healthy homeostatic conditions, neither morphological nor functional properties of microglia mirror those of classical macrophages. Indeed, microglia adapt exceptionally well to their microenvironment, becoming a legitimate member of the cellular brain architecture. The ramified or surveillant microglia in the young adult brain are characterized by specific morphology (small cell body and long, thin motile processes) and physiology (a unique pattern of Ca2+ signaling, responsiveness to various neurotransmitters and hormones, in addition to classic “immune” stimuli). Their numerous physiological functions far exceed and complement their immune capabilities. As the brain ages, the respective changes in the microglial microenvironment impact the functional properties of microglia, triggering further rounds of adaptation. In this review, we discuss the recent data showing how functional properties of microglia adapt to age-related changes in brain parenchyma in a sex-specific manner, with a specific focus on early changes occurring at middle age as well as some strategies counteracting the aging of microglia.
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208
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Blanke N, Go V, Rosene DL, Bigio IJ. Quantitative birefringence microscopy for imaging the structural integrity of CNS myelin following circumscribed cortical injury in the rhesus monkey. NEUROPHOTONICS 2021; 8:015010. [PMID: 33763502 PMCID: PMC7984970 DOI: 10.1117/1.nph.8.1.015010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/04/2021] [Indexed: 05/12/2023]
Abstract
Significance: Myelin breakdown is likely a key factor in the loss of cognitive and motor function associated with many neurodegenerative diseases. Aim: New methods for imaging myelin structure are needed to characterize and quantify the degradation of myelin in standard whole-brain sections of nonhuman primates and in human brain. Approach: Quantitative birefringence microscopy (qBRM) is a label-free technique for rapid histopathological assessment of myelin structural breakdown following cortical injury in rhesus monkeys. Results: We validate birefringence microscopy for structural imaging of myelin in rhesus monkey brain sections, and we demonstrate the power of qBRM by characterizing the breakdown of myelin following cortical injury, as a model of stroke, in the motor cortex. Conclusions: Birefringence microscopy is a valuable tool for histopathology of myelin and for quantitative assessment of myelin structure. Compared to conventional methods, this label-free technique is sensitive to subtle changes in myelin structure, is fast, and enables more quantitative assessment, without the variability inherent in labeling procedures such as immunohistochemistry.
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Affiliation(s)
- Nathan Blanke
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Veronica Go
- Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, Massachusetts, United States
| | - Douglas L. Rosene
- Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, Massachusetts, United States
| | - Irving J. Bigio
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Department of Electrical and Computer Engineering, Boston, Massachusetts, United States
- Address all correspondence to Irving J. Bigio,
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209
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Berghoff SA, Spieth L, Sun T, Hosang L, Schlaphoff L, Depp C, Düking T, Winchenbach J, Neuber J, Ewers D, Scholz P, van der Meer F, Cantuti-Castelvetri L, Sasmita AO, Meschkat M, Ruhwedel T, Möbius W, Sankowski R, Prinz M, Huitinga I, Sereda MW, Odoardi F, Ischebeck T, Simons M, Stadelmann-Nessler C, Edgar JM, Nave KA, Saher G. Microglia facilitate repair of demyelinated lesions via post-squalene sterol synthesis. Nat Neurosci 2021; 24:47-60. [PMID: 33349711 PMCID: PMC7116742 DOI: 10.1038/s41593-020-00757-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/12/2020] [Indexed: 01/23/2023]
Abstract
The repair of inflamed, demyelinated lesions as in multiple sclerosis (MS) necessitates the clearance of cholesterol-rich myelin debris by microglia/macrophages and the switch from a pro-inflammatory to an anti-inflammatory lesion environment. Subsequently, oligodendrocytes increase cholesterol levels as a prerequisite for synthesizing new myelin membranes. We hypothesized that lesion resolution is regulated by the fate of cholesterol from damaged myelin and oligodendroglial sterol synthesis. By integrating gene expression profiling, genetics and comprehensive phenotyping, we found that, paradoxically, sterol synthesis in myelin-phagocytosing microglia/macrophages determines the repair of acutely demyelinated lesions. Rather than producing cholesterol, microglia/macrophages synthesized desmosterol, the immediate cholesterol precursor. Desmosterol activated liver X receptor (LXR) signaling to resolve inflammation, creating a permissive environment for oligodendrocyte differentiation. Moreover, LXR target gene products facilitated the efflux of lipid and cholesterol from lipid-laden microglia/macrophages to support remyelination by oligodendrocytes. Consequently, pharmacological stimulation of sterol synthesis boosted the repair of demyelinated lesions, suggesting novel therapeutic strategies for myelin repair in MS.
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Affiliation(s)
- Stefan A Berghoff
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Institute for Medical Systems Biology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
| | - Leon Hosang
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Lennart Schlaphoff
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Constanze Depp
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Tim Düking
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Jan Winchenbach
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Jonathan Neuber
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - David Ewers
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Department of Clinical Neurophysiology, University Medical Centre Göttingen, Göttingen, Germany
- Department of Neurology, University Medical Centre, Göttingen, Germany
| | - Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | | | - Ludovico Cantuti-Castelvetri
- Institute of Neuronal Cell Biology, Technical University Munich, German Center for Neurodegenerative Diseases, Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Andrew O Sasmita
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Roman Sankowski
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Inge Huitinga
- Neuroimmunology Research Group, Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Department of Clinical Neurophysiology, University Medical Centre Göttingen, Göttingen, Germany
- Department of Neurology, University Medical Centre, Göttingen, Germany
| | - Francesca Odoardi
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
- Service Unit for Metabolomics and Lipidomics, Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, German Center for Neurodegenerative Diseases, Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | | | - Julia M Edgar
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Applied Neurobiology Group, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
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210
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Martins-Ferreira R, Leal B, Costa PP, Ballestar E. Microglial innate memory and epigenetic reprogramming in neurological disorders. Prog Neurobiol 2020; 200:101971. [PMID: 33309803 DOI: 10.1016/j.pneurobio.2020.101971] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/30/2020] [Accepted: 12/06/2020] [Indexed: 02/06/2023]
Abstract
Microglia are myeloid-derived cells recognized as brain-resident macrophages. They act as the first and main line of immune defense in the central nervous system (CNS). Microglia have high phenotypic plasticity and are essential for regulating healthy brain homeostasis, and their dysregulation underlies the onset and progression of several CNS pathologies through impaired inflammatory responses. Aberrant microglial activation, following an inflammatory insult, is associated with epigenetic dysregulation in various CNS pathologies. Emerging data suggest that certain stimuli to myeloid cells determine enhanced or attenuated responses to subsequent stimuli. These phenomena, generally termed innate immune memory (IIM), are highly dependent on epigenetic reprogramming. Microglial priming has been reported in several neurological diseases and corresponds to a state of increased permissiveness or exacerbated response, promoted by continuous exposure to a chronic pro-inflammatory environment. In this article, we provide extensive evidence of these epigenetic-mediated phenomena under neurological conditions and discuss their contribution to pathogenesis and their clinical implications, including those concerning potential novel therapeutic approaches.
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Affiliation(s)
- Ricardo Martins-Ferreira
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain; Immunogenetics Lab, Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto De Ciências Biomédicas Abel Salazar - Universidade Do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Barbara Leal
- Immunogenetics Lab, Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto De Ciências Biomédicas Abel Salazar - Universidade Do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Paulo Pinho Costa
- Immunogenetics Lab, Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto De Ciências Biomédicas Abel Salazar - Universidade Do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Esteban Ballestar
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916, Badalona, Barcelona, Spain.
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211
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Cellular senescence and failure of myelin repair in multiple sclerosis. Mech Ageing Dev 2020; 192:111366. [DOI: 10.1016/j.mad.2020.111366] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/10/2020] [Accepted: 09/23/2020] [Indexed: 01/10/2023]
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212
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Lewcock JW, Schlepckow K, Di Paolo G, Tahirovic S, Monroe KM, Haass C. Emerging Microglia Biology Defines Novel Therapeutic Approaches for Alzheimer’s Disease. Neuron 2020; 108:801-821. [DOI: 10.1016/j.neuron.2020.09.029] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/19/2020] [Accepted: 09/22/2020] [Indexed: 02/01/2023]
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213
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Shi L, Rocha M, Zhang W, Jiang M, Li S, Ye Q, Hassan SH, Liu L, Adair MN, Xu J, Luo J, Hu X, Wechsler LR, Chen J, Shi Y. Genome-wide transcriptomic analysis of microglia reveals impaired responses in aged mice after cerebral ischemia. J Cereb Blood Flow Metab 2020; 40:S49-S66. [PMID: 32438860 PMCID: PMC7687039 DOI: 10.1177/0271678x20925655] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Senescence-associated alterations in microglia may have profound impact on cerebral homeostasis and stroke outcomes. However, the lack of a transcriptome-wide comparison between young and aged microglia in the context of ischemia limits our understanding of aging-related mechanisms. Herein, we performed RNA sequencing analysis of microglia purified from cerebral hemispheres of young adult (10-week-old) and aged (18-month-old) mice five days after distal middle cerebral artery occlusion or after sham operation. Considerable transcriptional differences were observed between young and aged microglia in healthy brains, indicating heightened chronic inflammation in aged microglia. Following stroke, the overall transcriptional activation was more robust (>13-fold in the number of genes upregulated) in young microglia than in aged microglia. Gene clusters with functional implications in immune inflammatory responses, immune cell chemotaxis, tissue remodeling, and cell-cell interactions were markedly activated in microglia of young but not aged stroke mice. Consistent with the genomic profiling predictions, post-stroke cerebral infiltration of peripheral immune cells was markedly decreased in aged mice compared to young mice. Moreover, post-ischemic aged microglia demonstrated reduced interaction with neighboring neurons and diminished polarity toward the infarct lesion. These alterations in microglial gene response and behavior may contribute to aging-driven vulnerability and poorer recovery after ischemic stroke.
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Affiliation(s)
- Ligen Shi
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marcelo Rocha
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wenting Zhang
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ming Jiang
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sicheng Li
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qing Ye
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA.,Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
| | - Sulaiman H Hassan
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Liqiang Liu
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Maya N Adair
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jing Xu
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jianhua Luo
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoming Hu
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA.,Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
| | - Lawrence R Wechsler
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jun Chen
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA.,Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
| | - Yejie Shi
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery and UPMC Stroke Institute, University of Pittsburgh, Pittsburgh, PA, USA.,Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
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214
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Gowrishankar S, Cologna SM, Givogri MI, Bongarzone ER. Deregulation of signalling in genetic conditions affecting the lysosomal metabolism of cholesterol and galactosyl-sphingolipids. Neurobiol Dis 2020; 146:105142. [PMID: 33080336 PMCID: PMC8862610 DOI: 10.1016/j.nbd.2020.105142] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 09/04/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
The role of lipids in neuroglial function is gaining momentum in part due to a better understanding of how many lipid species contribute to key cellular signalling pathways at the membrane level. The description of lipid rafts as membrane domains composed by defined classes of lipids such as cholesterol and sphingolipids has greatly helped in our understanding of how cellular signalling can be regulated and compartmentalized in neurons and glial cells. Genetic conditions affecting the metabolism of these lipids greatly impact on how some of these signalling pathways work, providing a context to understand the biological function of the lipid. Expectedly, abnormal metabolism of several lipids such as cholesterol and galactosyl-sphingolipids observed in several metabolic conditions involving lysosomal dysfunction are often accompanied by neuronal and myelin dysfunction. This review will discuss the role of lysosomal biology in the context of deficiencies in the metabolism of cholesterol and galactosyl-sphingolipids and their impact on neural function in three genetic disorders: Niemann-Pick type C, Metachromatic leukodystrophy and Krabbe's disease.
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Affiliation(s)
- S Gowrishankar
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
| | - S M Cologna
- Department of Chemistry, University of Illinois, Chicago, IL, USA.
| | - M I Givogri
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
| | - E R Bongarzone
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
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215
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Autophagy Pathways in CNS Myeloid Cell Immune Functions. Trends Neurosci 2020; 43:1024-1033. [DOI: 10.1016/j.tins.2020.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/17/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023]
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216
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Lochocki B, Morrema THJ, Ariese F, Hoozemans JJM, de Boer JF. The search for a unique Raman signature of amyloid-beta plaques in human brain tissue from Alzheimer's disease patients. Analyst 2020; 145:1724-1736. [PMID: 31907497 DOI: 10.1039/c9an02087j] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Definite Alzheimer's disease (AD) diagnosis is commonly done on ex vivo brain tissue using immuno-histochemical staining to visualize amyloid-beta (Aβ) aggregates, also known as Aβ plaques. Raman spectroscopy has shown its potential for non-invasive and label-free determination of bio-molecular compositions, aiding the post-mortem diagnosis of pathological tissue. Here, we investigated whether conventional Raman spectroscopy could be used for the detection of amyloid beta deposits in fixed, ex vivo human brain tissue, taken from the frontal cortex region. We examined the spectra and spectral maps of three severe AD cases and two healthy control cases and compared their spectral outcome among each other as well as to recent results in the literature obtained with various spectroscopic techniques. After hyperspectral Raman mapping, Aβ plaques were visualized using Thioflavin-S staining on the exact same tissue sections. As a result, we show that tiny diffuse or tangled-like morphological structures, visible under microscopic conditions on unstained tissue and often but erroneously assumed to be deposits of Aβ, are instead usually an aggregation of highly auto-fluorescent lipofuscin granulates without any, or limited, plaque or plaque-like association. The occurrence of these auto-fluorescent particles is equally distributed in both AD and healthy control cases. Therefore, they cannot be used as possible criteria for Alzheimer's disease diagnosis. Furthermore, a unique plaque-specific/Aβ spectrum could not be determined even after possible spectral interferences were carefully removed.
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Affiliation(s)
- Benjamin Lochocki
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU Amsterdam, The Netherlands.
| | - Tjado H J Morrema
- Department of Pathology, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Freek Ariese
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU Amsterdam, The Netherlands.
| | - Jeroen J M Hoozemans
- Department of Pathology, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Johannes F de Boer
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU Amsterdam, The Netherlands.
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217
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Mishra A, Shang Y, Wang Y, Bacon ER, Yin F, Brinton RD. Dynamic Neuroimmune Profile during Mid-life Aging in the Female Brain and Implications for Alzheimer Risk. iScience 2020; 23:101829. [PMID: 33319170 PMCID: PMC7724165 DOI: 10.1016/j.isci.2020.101829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/13/2020] [Accepted: 11/16/2020] [Indexed: 12/24/2022] Open
Abstract
Aging and endocrine transition states can significantly impact inflammation across organ systems. Neuroinflammation is well documented in Alzheimer disease (AD). Herein, we investigated neuroinflammation that emerges during mid-life aging, chronological and endocrinological, in the female brain as an early initiating mechanism driving AD risk later in life. Analyses were conducted in a translational rodent model of mid-life chronological and endocrinological aging followed by validation in transcriptomic profiles from women versus age-matched men. In the translational model, the neuroinflammatory profile of mid-life aging in females was endocrine and chronological state specific, dynamic, anatomically distributed, and persistent. Microarray dataset analyses of aging human hippocampus indicated a sex difference in neuroinflammatory profile in which women exhibited a profile comparable to the pattern discovered in our translational rodent model, whereas age-matched men exhibited a profile consistent with low neuroimmune activation. Translationally, these findings have implications for therapeutic interventions during mid-life to decrease late-onset AD risk.
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Affiliation(s)
- Aarti Mishra
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ 85719, USA
| | - Yuan Shang
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ 85719, USA
| | - Yiwei Wang
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ 85719, USA
| | - Eliza R Bacon
- Department of Medical Oncology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Fei Yin
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ 85719, USA
| | - Roberta D Brinton
- Center for Innovation in Brain Science, University of Arizona, Tucson, AZ 85719, USA
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218
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Chen D, Huang Y, Shi Z, Li J, Zhang Y, Wang K, Smith AD, Gong Y, Gao Y. Demyelinating processes in aging and stroke in the central nervous system and the prospect of treatment strategy. CNS Neurosci Ther 2020; 26:1219-1229. [PMID: 33210839 PMCID: PMC7702227 DOI: 10.1111/cns.13497] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Demyelination occurs in response to brain injury and is observed in many neurodegenerative diseases. Myelin is synthesized from oligodendrocytes in the central nervous system, and oligodendrocyte death‐induced demyelination is one of the mechanisms involved in white matter damage after stroke and neurodegeneration. Oligodendrocyte precursor cells (OPCs) exist in the brain of normal adults, and their differentiation into mature oligodendrocytes play a central role in remyelination. Although the differentiation and maturity of OPCs drive endogenous efforts for remyelination, the failure of axons to remyelinate is still the biggest obstacle to brain repair after injury or diseases. In recent years, studies have made attempts to promote remyelination after brain injury and disease, but its cellular or molecular mechanism is not yet fully understood. In this review, we discuss recent studies examining the demyelination process and potential therapeutic strategies for remyelination in aging and stroke. Based on our current understanding of the cellular and molecular mechanisms underlying remyelination, we hypothesize that myelin and oligodendrocytes are viable therapeutic targets to mitigate brain injury and to treat demyelinating‐related neurodegeneration diseases.
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Affiliation(s)
- Di Chen
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yichen Huang
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ziyu Shi
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Jiaying Li
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yue Zhang
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ke Wang
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Amanda D Smith
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
| | - Ye Gong
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yanqin Gao
- Department of Critical Care Medicine and Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
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219
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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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220
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Xie D, He M, Hu X. Microglia/macrophage diversities in central nervous system physiology and pathology. CNS Neurosci Ther 2020; 25:1287-1289. [PMID: 31793210 PMCID: PMC7154592 DOI: 10.1111/cns.13257] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/21/2019] [Accepted: 10/21/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Di Xie
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Maxine He
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Xiaoming Hu
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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221
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Lubart A, Benbenishty A, Har-Gil H, Laufer H, Gdalyahu A, Assaf Y, Blinder P. Single Cortical Microinfarcts Lead to Widespread Microglia/Macrophage Migration Along the White Matter. Cereb Cortex 2020; 31:248-266. [PMID: 32954425 DOI: 10.1093/cercor/bhaa223] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 12/31/2022] Open
Abstract
Loss of cognitive function with aging is a complex and poorly understood process. Recently, clinical research has linked the occurrence of cortical microinfarcts to cognitive decline. Cortical microinfarcts form following the occlusion of penetrating vessels and are considered to be restricted to the proximity of the occluded vessel. Whether and how such local events propagate and affect remote brain regions remain unknown. To this end, we combined histological analysis and longitudinal diffusion tensor imaging (DTI), following the targeted-photothrombotic occlusion of single cortical penetrating vessels. Occlusions resulted in distant tissue reorganization across the mouse brain. This remodeling co-occurred with the formation of a microglia/macrophage migratory path along subcortical white matter tracts, reaching the contralateral hemisphere through the corpus callosum and leaving a microstructural signature detected by DTI-tractography. CX3CR1-deficient mice exhibited shorter trail lengths, differential remodeling, and only ipsilateral white matter tract changes. We concluded that microinfarcts lead to brain-wide remodeling in a microglial CX3CR1-dependent manner.
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Affiliation(s)
- Alisa Lubart
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amit Benbenishty
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Biological Regulation Department, The Weizmann Institute of Science, Rehovot, Israel
| | - Hagai Har-Gil
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Hadas Laufer
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amos Gdalyahu
- Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Yaniv Assaf
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Pablo Blinder
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
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222
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Role of Microglia in Modulating Adult Neurogenesis in Health and Neurodegeneration. Int J Mol Sci 2020; 21:ijms21186875. [PMID: 32961703 PMCID: PMC7555074 DOI: 10.3390/ijms21186875] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 09/18/2020] [Indexed: 02/06/2023] Open
Abstract
Microglia are the resident immune cells of the brain, constituting the powerhouse of brain innate immunity. They originate from hematopoietic precursors that infiltrate the developing brain during different stages of embryogenesis, acquiring a phenotype characterized by the presence of dense ramifications. Microglial cells play key roles in maintaining brain homeostasis and regulating brain immune responses. They continuously scan and sense the brain environment to detect any occurring changes. Upon detection of a signal related to physiological or pathological processes, the cells are activated and transform to an amoeboid-like phenotype, mounting adequate responses that range from phagocytosis to secretion of inflammatory and trophic factors. The overwhelming evidence suggests that microglia are crucially implicated in influencing neuronal proliferation and differentiation, as well as synaptic connections, and thereby cognitive and behavioral functions. Here, we review the role of microglia in adult neurogenesis under physiological conditions, and how this role is affected in neurodegenerative diseases.
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223
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Vanhunsel S, Beckers A, Moons L. Designing neuroreparative strategies using aged regenerating animal models. Ageing Res Rev 2020; 62:101086. [PMID: 32492480 DOI: 10.1016/j.arr.2020.101086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/13/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022]
Abstract
In our ever-aging world population, the risk of age-related neuropathies has been increasing, representing both a social and economic burden to society. Since the ability to regenerate in the adult mammalian central nervous system is very limited, brain trauma and neurodegeneration are often permanent. As a consequence, novel scientific challenges have emerged and many research efforts currently focus on triggering repair in the damaged or diseased brain. Nevertheless, stimulating neuroregeneration remains ambitious. Even though important discoveries have been made over the past decades, they did not translate into a therapy yet. Actually, this is not surprising; while these disorders mainly manifest in aged individuals, most of the research is being performed in young animal models. Aging of neurons and their environment, however, greatly affects the central nervous system and its capacity to repair. This review provides a detailed overview of the impact of aging on central nervous system functioning and regeneration potential, both in non-regenerating and spontaneously regenerating animal models. Additionally, we highlight the need for aging animal models with regenerative capacities in the search for neuroreparative strategies.
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Affiliation(s)
- Sophie Vanhunsel
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - An Beckers
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium.
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224
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Dwyer CM, Nguyen LTT, Healy LM, Dutta R, Ludwin S, Antel J, Binder MD, Kilpatrick TJ. Multiple Sclerosis as a Syndrome-Implications for Future Management. Front Neurol 2020; 11:784. [PMID: 32982904 PMCID: PMC7483755 DOI: 10.3389/fneur.2020.00784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/25/2020] [Indexed: 12/25/2022] Open
Abstract
We propose that multiple sclerosis (MS) is best characterized as a syndrome rather than a single disease because different pathogenetic mechanisms can result in the constellation of symptoms and signs by which MS is clinically characterized. We describe several cellular mechanisms that could generate inflammatory demyelination through disruption of homeostatic interactions between immune and neural cells. We illustrate that genomics is important in identifying phenocopies, in particular for primary progressive MS. We posit that molecular profiling, rather than traditional clinical phenotyping, will facilitate meaningful patient stratification, as illustrated by interactions between HLA and a regulator of homeostatic phagocytosis, MERTK. We envisage a personalized approach to MS management where genetic, molecular, and cellular information guides management.
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Affiliation(s)
- Christopher M Dwyer
- Florey Institute of Neuroscience and Mental Health, Florey Department, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Linda Thien-Trang Nguyen
- Florey Institute of Neuroscience and Mental Health, Florey Department, The University of Melbourne, Parkville, VIC, Australia
| | - Luke M Healy
- Neuroimmunology Unit, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Ranjan Dutta
- Department of Neurosciences, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Samuel Ludwin
- Neuroimmunology Unit, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Jack Antel
- Neuroimmunology Unit, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Michele D Binder
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, Australia
| | - Trevor J Kilpatrick
- Florey Institute of Neuroscience and Mental Health, Florey Department, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, VIC, Australia
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225
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Acute brain injuries trigger microglia as an additional source of the proteoglycan NG2. Acta Neuropathol Commun 2020; 8:146. [PMID: 32843103 PMCID: PMC7449013 DOI: 10.1186/s40478-020-01016-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/10/2020] [Indexed: 01/07/2023] Open
Abstract
NG2 is a type I transmembrane glycoprotein known as chondroitin sulfate proteoglycan 4 (CSPG4). In the healthy central nervous system, NG2 is exclusively expressed by oligodendrocyte progenitor cells and by vasculature pericytes. A large body of immunohistochemical studies showed that under pathological conditions such as acute brain injuries and experimental autoimmune encephalomyelitis (EAE), a number of activated microglia were NG2 immuno-positive, suggesting NG2 expression in these cells. Alternative explanations for the microglial NG2 labeling consider the biochemical properties of NG2 or the phagocytic activity of activated microglia. Reportedly, the transmembrane NG2 proteoglycan can be cleaved by a variety of proteases to deposit the NG2 ectodomain into the extracellular matrix. The ectodomain, however, could also stick to the microglial surface. Since microglia are phagocytic cells engulfing debris of dying cells, it is difficult to identify a genuine expression of NG2. Recent studies showing (1) pericytes giving rise to microglial after stroke, and (2) immune cells of NG2-EYFP knock-in mice lacking NG2 expression in an EAE model generated doubts for the de novo expression of NG2 in microglia after acute brain injuries. In the current study, we took advantage of three knock-in mouse lines (NG2-CreERT2, CX3CR1-EGFP and NG2-EYFP) to study NG2 expression indicated by transgenic fluorescent proteins in microglia after tMCAO (transient middle cerebral artery occlusion) or cortical stab wound injury (SWI). We provide strong evidence that NG2-expressing cells, including OPCs and pericytes, did not differentiate into microglia after acute brain injuries, whereas activated microglia did express NG2 in a disease-dependent manner. A subset of microglia continuously activated the NG2 gene at least within the first week after tMCAO, whereas within 3 days after SWI a limited number of microglia at the lesion site transiently expressed NG2. Immunohistochemical studies demonstrated that these microglia with NG2 gene activity also synthesized the NG2 protein, suggesting activated microglia as an additional source of the NG2 proteoglycan after acute brain injuries.
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226
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Chausse B, Kakimoto PA, Kann O. Microglia and lipids: how metabolism controls brain innate immunity. Semin Cell Dev Biol 2020; 112:137-144. [PMID: 32807643 DOI: 10.1016/j.semcdb.2020.08.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 12/26/2022]
Abstract
Microglia are universal sensors of alterations in CNS physiology. These cells integrate complex molecular signals and undergo comprehensive phenotypical remodeling to adapt inflammatory responses. In the last years, single-cell analyses have revealed that microglia exhibit diverse phenotypes during development, growth and disease. Emerging evidence suggests that such phenotype transitions are mediated by reprogramming of cell metabolism. Indeed, metabolic pathways are distinctively altered in activated microglia and are central nodes controlling microglial responses. Microglial lipid metabolism has been specifically involved in the control of microglial activation and effector functions, such as migration, phagocytosis and inflammatory signaling, and minor disturbances in microglial lipid handling associates with altered brain function in disorders featuring neuroinflammation. In this review, we explore new and relevant aspects of microglial metabolism in health and disease. We give special focus on how different branches of lipid metabolism, such as lipid sensing, synthesis and oxidation, integrate and control essential aspects of microglial biology, and how disturbances in these processes associate with aging and the pathogenesis of, for instance, multiple sclerosis and Alzheimer's disease. Finally, challenges and advances in microglial lipid research are discussed.
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Affiliation(s)
- Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany.
| | - Pamela A Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, Brazil
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences, University of Heidelberg, D-69120 Heidelberg, Germany
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227
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Morgan ML, Kaushik DK, Stys PK, Caprariello AV. Autofluorescence spectroscopy as a proxy for chronic white matter pathology. Mult Scler 2020; 27:1046-1056. [PMID: 32779553 DOI: 10.1177/1352458520948221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The balance of tissue injury and repair ultimately determines outcomes of chronic neurological disorders, such as progressive multiple sclerosis (MS). However, the extent of pathology can be difficult to detect, particularly when it is insidious and/or offset by tissue regeneration. OBJECTIVES The objective of this research is to evaluate whether tissue autofluorescence-typically a source of contamination-provides a surrogate marker of white matter injury. METHODS Tissue autofluorescence in autopsied specimens both experimental and clinical was characterized by spectral confocal microscopy and correlated to severity and chronicity as determined by standard histopathology. RESULTS Months after cuprizone (CPZ)-induced demyelination, despite robust remyelination, autofluorescent deposits progressively accumulated in regions of prior pathology. Autofluorescent deposits (likely reflecting myelin debris remnants) were conspicuously localized to white matter, proportional to lesion severity, and displayed differential fluorescence over time. Strikingly, similar features were apparent also in autopsied MS tissue. CONCLUSION Autofluorescence spectroscopy illuminates prior and ongoing white matter injury. The accumulation of autofluorescence in proportion to the extent of progressive atrophy, despite robust remyelination in the CPZ brain, provides important proof-of-concept of a phenomenon (insidious ongoing damage masked by mechanisms of tissue repair) that we hypothesize is highly relevant to the progressive phase of MS.
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Affiliation(s)
- Megan L Morgan
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Deepak K Kaushik
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Peter K Stys
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Andrew V Caprariello
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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228
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Rawji KS, Gonzalez Martinez GA, Sharma A, Franklin RJ. The Role of Astrocytes in Remyelination. Trends Neurosci 2020; 43:596-607. [DOI: 10.1016/j.tins.2020.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/05/2020] [Accepted: 05/26/2020] [Indexed: 12/21/2022]
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229
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McCarthy DM, Lowe SE, Morgan TJ, Cannon EN, Biederman J, Spencer TJ, Bhide PG. Transgenerational transmission of behavioral phenotypes produced by exposure of male mice to saccharin and nicotine. Sci Rep 2020; 10:11974. [PMID: 32686722 PMCID: PMC7371742 DOI: 10.1038/s41598-020-68883-6] [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: 03/08/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022] Open
Abstract
The use of non-nutritive sweeteners such as saccharin is widely prevalent. Although saccharin is considered safe for human consumption, it produces behavioral changes in experimental animals. We report that saccharin’s behavioral effects are much more pervasive than currently recognized. In a mouse model, saccharin exposure produced motor impulsivity not only in the saccharin-exposed males but also in their offspring. In addition, the offspring showed locomotor hyperactivity and working memory deficit not observed in fathers. Spermatazoal DNA was hypermethylated in the saccharin-exposed fathers, especially at dopamine receptor promoter regions, suggesting that epigenetic modification of germ cell DNA may mediate transgenerational transmission of behavioral phenotypes. Dopamine’s role in hyperactivity was further highlighted by the finding that the stimulant drug methylphenidate mitigated the hyperactivity. Nicotine is another substance that is widely used. Its use via smokeless tobacco products, some of which contain saccharin, is on the rise contributing to concerns about adverse outcomes of co-exposure to saccharin and nicotine. We found that co-exposure of male mice to saccharin and nicotine produced significant behavioral impairment in their offspring. Thus, our data point to potential adverse neurobehavioral consequences of exposure to saccharin alone or saccharin and nicotine for the exposed individuals and their descendants.
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Affiliation(s)
- Deirdre M McCarthy
- Biomedical Sciences and Center for Brain Repair, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA
| | - Sarah E Lowe
- Biomedical Sciences and Center for Brain Repair, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA
| | - Thomas J Morgan
- Biomedical Sciences and Center for Brain Repair, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA.,School of Physician Assistant Practice, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA
| | - Elisa N Cannon
- Biomedical Sciences and Center for Brain Repair, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA
| | - Joseph Biederman
- Pediatric Psychopharmacology, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Thomas J Spencer
- Pediatric Psychopharmacology, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Pradeep G Bhide
- Biomedical Sciences and Center for Brain Repair, College of Medicine, Florida State University, 1115, West Call Street, Tallahassee, FL, 32306, USA.
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230
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Kokkosis AG, Tsirka SE. Neuroimmune Mechanisms and Sex/Gender-Dependent Effects in the Pathophysiology of Mental Disorders. J Pharmacol Exp Ther 2020; 375:175-192. [PMID: 32661057 DOI: 10.1124/jpet.120.266163] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022] Open
Abstract
Innate and adaptive immune mechanisms have emerged as critical regulators of CNS homeostasis and mental health. A plethora of immunologic factors have been reported to interact with emotion- and behavior-related neuronal circuits, modulating susceptibility and resilience to mental disorders. However, it remains unclear whether immune dysregulation is a cardinal causal factor or an outcome of the pathologies associated with mental disorders. Emerging variations in immune regulatory pathways based on sex differences provide an additional framework for discussion in these psychiatric disorders. In this review, we present the current literature pertaining to the effects that disrupted immune pathways have in mental disorder pathophysiology, including immune dysregulation in CNS and periphery, microglial activation, and disturbances of the blood-brain barrier. In addition, we present the suggested origins of such immune dysregulation and discuss the gender and sex influence of the neuroimmune substrates that contribute to mental disorders. The findings challenge the conventional view of these disorders and open the window to a diverse spectrum of innovative therapeutic targets that focus on the immune-specific pathophenotypes in neuronal circuits and behavior. SIGNIFICANCE STATEMENT: The involvement of gender-dependent inflammatory mechanisms on the development of mental pathologies is gaining momentum. This review addresses these novel factors and presents the accumulating evidence introducing microglia and proinflammatory elements as critical components and potential targets for the treatment of mental disorders.
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Affiliation(s)
- Alexandros G Kokkosis
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York
| | - Stella E Tsirka
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York
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231
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Salas IH, Burgado J, Allen NJ. Glia: victims or villains of the aging brain? Neurobiol Dis 2020; 143:105008. [PMID: 32622920 DOI: 10.1016/j.nbd.2020.105008] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/14/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
Aging is the strongest risk factor for metabolic, vascular and neurodegenerative diseases. Aging alone is associated with a gradual decline of cognitive and motor functions. Considering an increasing elderly population in the last century, understanding the cellular and molecular mechanisms contributing to brain aging is of vital importance. Recent genetic and transcriptomic findings strongly suggest that glia are the first cells changing with aging. Glial cells constitute around 50% of the total cells in the brain and play key roles regulating brain homeostasis in health and disease. Their essential functions include providing nutritional support to neurons, activation of immune responses, and regulation of synaptic transmission and plasticity. In this review we discuss how glia are altered in the aging brain and whether these alterations are protective or contribute to the age-related pathological cascade. We focus on the major morphological, transcriptional and functional changes affecting glia in a range of systems, including human, non-human primates, and rodents. We also highlight future directions for investigating the roles of glia in brain aging.
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Affiliation(s)
- Isabel H Salas
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jillybeth Burgado
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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232
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Saez-Atienzar S, Masliah E. Cellular senescence and Alzheimer disease: the egg and the chicken scenario. Nat Rev Neurosci 2020; 21:433-444. [PMID: 32601397 DOI: 10.1038/s41583-020-0325-z] [Citation(s) in RCA: 136] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2020] [Indexed: 12/21/2022]
Abstract
Globally, 50 million people live with dementia, with Alzheimer disease (AD) being responsible for two-thirds of the total cases. As ageing is the main risk factor for dementia-related neurodegeneration, changes in the timing or nature of the cellular hallmarks of normal ageing might be key to understanding the events that convert normal ageing into neurodegeneration. Cellular senescence is a candidate mechanism that might be important for this conversion. Under persistent stress, as occurs in ageing, both postmitotic cells - including neurons - and proliferative cells - such as astrocytes and microglia, among others - can engender a state of chronic cellular senescence that is characterized by the secretion of pro-inflammatory molecules that promote the functional decline of tissues and organs. Ablation of senescent cells has been postulated as a promising therapeutic venue to target the ageing phenotype and, thus, prevent or mitigate ageing-related diseases. However, owing to a lack of evidence, it is not possible to label cellular senescence as a cause or a consequence of neurodegeneration. This Review examines cellular senescence in the context of ageing and AD, and discusses which of the processes - cellular senescence or AD - might come first.
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Affiliation(s)
- Sara Saez-Atienzar
- Neuromuscular Disease Research Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Eliezer Masliah
- Molecular Neuropathology Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA. .,Division of Neuroscience, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
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233
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Burns JC, Cotleur B, Walther DM, Bajrami B, Rubino SJ, Wei R, Franchimont N, Cotman SL, Ransohoff RM, Mingueneau M. Differential accumulation of storage bodies with aging defines discrete subsets of microglia in the healthy brain. eLife 2020; 9:e57495. [PMID: 32579115 PMCID: PMC7367682 DOI: 10.7554/elife.57495] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/21/2020] [Indexed: 12/19/2022] Open
Abstract
To date, microglia subsets in the healthy CNS have not been identified. Utilizing autofluorescence (AF) as a discriminating parameter, we identified two novel microglia subsets in both mice and non-human primates, termed autofluorescence-positive (AF+) and negative (AF-). While their proportion remained constant throughout most adult life, the AF signal linearly and specifically increased in AF+ microglia with age and correlated with a commensurate increase in size and complexity of lysosomal storage bodies, as detected by transmission electron microscopy and LAMP1 levels. Post-depletion repopulation kinetics revealed AF- cells as likely precursors of AF+ microglia. At the molecular level, the proteome of AF+ microglia showed overrepresentation of endolysosomal, autophagic, catabolic, and mTOR-related proteins. Mimicking the effect of advanced aging, genetic disruption of lysosomal function accelerated the accumulation of storage bodies in AF+ cells and led to impaired microglia physiology and cell death, suggestive of a mechanistic convergence between aging and lysosomal storage disorders.
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Affiliation(s)
- Jeremy Carlos Burns
- Multiple Sclerosis & Neurorepair Research Unit, BiogenCambridgeUnited States
- Department of Pharmacology & Experimental Therapeutics, Boston University School of MedicineBostonUnited States
| | - Bunny Cotleur
- Emerging Neurosciences Research Unit, BiogenCambridgeUnited States
| | | | - Bekim Bajrami
- Chemical Biology and ProteomicsCambridgeUnited States
| | - Stephen J Rubino
- Multiple Sclerosis & Neurorepair Research Unit, BiogenCambridgeUnited States
| | - Ru Wei
- Chemical Biology and ProteomicsCambridgeUnited States
| | | | - Susan L Cotman
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | | | - Michael Mingueneau
- Multiple Sclerosis & Neurorepair Research Unit, BiogenCambridgeUnited States
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234
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Bonomo R, Cavaletti G, Skene DJ. Metabolomics markers in Neurology: current knowledge and future perspectives for therapeutic targeting. Expert Rev Neurother 2020; 20:725-738. [PMID: 32538242 DOI: 10.1080/14737175.2020.1782746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Metabolomics is an emerging approach providing new insights into the metabolic changes and underlying mechanisms involved in the pathogenesis of neurological disorders. AREAS COVERED Here, the authors present an overview of the current knowledge of metabolic profiling (metabolomics) to provide critical insight on the role of biochemical markers and metabolic alterations in neurological diseases. EXPERT OPINION Elucidation of characteristic metabolic alterations in neurological disorders is crucial for a better understanding of their pathogenesis, and for identifying potential biomarkers and drug targets. Nevertheless, discrepancies in diagnostic criteria, sample handling protocols, and analytical methods still affect the generalizability of current study results.
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Affiliation(s)
- Roberta Bonomo
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy.,Chronobiology, Faculty of Health and Medical Sciences, University of Surrey , Guildford, UK
| | - Guido Cavaletti
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca , Monza, Italy
| | - Debra J Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey , Guildford, UK
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235
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Alzheimer's-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci 2020; 23:927-938. [PMID: 32514138 DOI: 10.1038/s41593-020-0650-6] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 05/01/2020] [Indexed: 02/08/2023]
Abstract
Human genetic data indicate that microglial dysfunction contributes to the pathology of Alzheimer's disease (AD), exemplified by the identification of coding variants in triggering receptor expressed on myeloid cells 2 (TREM2) and, more recently, in PLCG2, a phospholipase-encoding gene expressed in microglia. Although studies in mouse models have implicated specific Trem2-dependent microglial functions in AD, the underlying molecular mechanisms and translatability to human disease remain poorly defined. In this study, we used genetically engineered human induced pluripotent stem cell-derived microglia-like cells to show that TREM2 signals through PLCγ2 to mediate cell survival, phagocytosis, processing of neuronal debris, and lipid metabolism. Loss of TREM2 or PLCγ2 signaling leads to a shared signature of transcriptional dysregulation that underlies these phenotypes. Independent of TREM2, PLCγ2 also signals downstream of Toll-like receptors to mediate inflammatory responses. Therefore, PLCγ2 activity regulates divergent microglial functions via distinct TREM2-dependent and -independent signaling and might be involved in the transition to a microglial state associated with neurodegenerative disease.
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236
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Ward H, West SJ. Microglia: sculptors of neuropathic pain? ROYAL SOCIETY OPEN SCIENCE 2020; 7:200260. [PMID: 32742693 PMCID: PMC7353970 DOI: 10.1098/rsos.200260] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/01/2020] [Indexed: 05/02/2023]
Abstract
Neuropathic pain presents a huge societal and individual burden. The limited efficacy of current analgesics, diagnostic markers and clinical trial outcome measures arises from an incomplete understanding of the underlying mechanisms. A large and growing body of evidence has established the important role of microglia in the onset and possible maintenance of neuropathic pain, and these cells may represent an important target for future therapy. Microglial research has further revealed their important role in structural remodelling of the nervous system. In this review, we aim to explore the evidence for microglia in sculpting nervous system structure and function, as well as their important role in neuropathic pain, and finally integrate these studies to synthesize a new model for microglia in somatosensory circuit remodelling, composed of six key and inter-related mechanisms. Summarizing the mechanisms through which microglia modulate nervous system structure and function helps to frame a better understanding of neuropathic pain, and provide a clear roadmap for future research.
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Affiliation(s)
- Harry Ward
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Steven J. West
- Sainsbury Wellcome Centre, University College London, 25 Howland St, London WC1E 6BT, UK
- Author for correspondence: Steven J. West e-mail:
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237
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Age-related cognitive decline in baboons: modeling the prodromal phase of Alzheimer's disease and related dementias. Aging (Albany NY) 2020; 12:10099-10116. [PMID: 32427127 PMCID: PMC7346018 DOI: 10.18632/aging.103272] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/01/2020] [Indexed: 12/12/2022]
Abstract
The aging of brain cells and synaptic loss are the major underlying pathophysiological processes contributing to the progressive decline in cognitive functions and Alzheimer’s disease. The difference in cognitive performances observed between adult and aged subjects across species highlights the decline of brain systems with age. The inflection point in age-related cognitive decline is important for our understanding of the pathophysiology of neurodegenerative diseases and for timing therapeutic interventions. Humans and nonhuman primates share many similarities including age-dependent changes in gene expression and decline in neural and immune functions. Given these evolutionary conserved organ systems, complex human-like behavioral and age-dependent changes may be modeled and monitored longitudinally in nonhuman primates. We integrated three clinically relevant outcome measures to investigate the effect of age on cognition, motor function and diurnal activity in aged baboons. We provide evidence of a naturally-occurring age-dependent precipitous decline in movement planning, in learning novel tasks, in simple discrimination and in motivation. These results suggest that baboons aged ~20 years (equivalent to ~60 year old humans) may offer a relevant model for the prodromal phase of Alzheimer’s disease and related dementias to investigate mechanisms involved in the precipitous decline in cognitive functions and to develop early therapeutic interventions
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238
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Kempthorne L, Yoon H, Madore C, Smith S, Wszolek ZK, Rademakers R, Kim J, Butovsky O, Dickson DW. Loss of homeostatic microglial phenotype in CSF1R-related Leukoencephalopathy. Acta Neuropathol Commun 2020; 8:72. [PMID: 32430064 PMCID: PMC7236286 DOI: 10.1186/s40478-020-00947-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 12/30/2022] Open
Abstract
Microglia are resident macrophages of the central nervous system, and their unique molecular signature is dependent upon CSF-1 signaling. Previous studies have demonstrated the importance of CSF-1R in survival and development of microglia in animal models, but the findings are of uncertain relevance to understanding the influence of CSF-1R on microglia in humans. Hereditary diffuse leukoencephalopathy with spheroids (HDLS) [also known as adult onset leukoencephalopathy with spheroids and pigmented glia (ALSP)] is a neurodegenerative disorder primarily affecting cerebral white matter, most often caused by mutations of CSF1R. Therefore, we hypothesized that the molecular profile of microglia may be affected in HDLS. Semi-quantitative immunohistochemistry and quantitative transcriptomic profiling revealed reduced expression of IBA-1 and P2RY12 in both white and gray matter microglia of HDLS. In contrast, there was increased expression of CD68 and CD163 in microglia in affected white matter. In addition, expression of selective and specific microglial markers, including P2RY12, CX3CR1 and CSF-1R, were reduced in affected white matter. These results suggest that microglia in white matter in HDLS lose their homeostatic phenotype. Supported by gene ontology analysis, it is likely that an inflammatory phenotype is a key pathogenic feature of microglia in vulnerable brain regions of HDLS. Our findings suggest a potential mechanism of disease pathogenesis by linking aberrant CSF-1 signaling to altered microglial phenotype. They also support the idea that HDLS may be a primary microgliopathy. We observed increased expression of CSF-2 in gray matter compared to affected white matter, which may contribute to selective vulnerability of white matter in HDLS. Our findings suggest that methods that restore the homeostatic phenotype of microglia might be considered treatment approaches in HDLS.
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Affiliation(s)
- Liam Kempthorne
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Institute of Neurology, University College London, London, UK
| | - Hyejin Yoon
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Charlotte Madore
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Scott Smith
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Zbigniew K Wszolek
- Department of Neurology, Mayo Clinic College of Medicine, Jacksonville, FL, USA
| | - Rosa Rademakers
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Jungsu Kim
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Oleg Butovsky
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Evergrande Center for Immunologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
- Neurobiology of Disease Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA.
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239
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Rawji KS, Young AMH, Ghosh T, Michaels NJ, Mirzaei R, Kappen J, Kolehmainen KL, Alaeiilkhchi N, Lozinski B, Mishra MK, Pu A, Tang W, Zein S, Kaushik DK, Keough MB, Plemel JR, Calvert F, Knights AJ, Gaffney DJ, Tetzlaff W, Franklin RJM, Yong VW. Niacin-mediated rejuvenation of macrophage/microglia enhances remyelination of the aging central nervous system. Acta Neuropathol 2020; 139:893-909. [PMID: 32030468 PMCID: PMC7181452 DOI: 10.1007/s00401-020-02129-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/19/2020] [Accepted: 01/23/2020] [Indexed: 12/17/2022]
Abstract
Remyelination following CNS demyelination restores rapid signal propagation and protects axons; however, its efficiency declines with increasing age. Both intrinsic changes in the oligodendrocyte progenitor cell population and extrinsic factors in the lesion microenvironment of older subjects contribute to this decline. Microglia and monocyte-derived macrophages are critical for successful remyelination, releasing growth factors and clearing inhibitory myelin debris. Several studies have implicated delayed recruitment of macrophages/microglia into lesions as a key contributor to the decline in remyelination observed in older subjects. Here we show that the decreased expression of the scavenger receptor CD36 of aging mouse microglia and human microglia in culture underlies their reduced phagocytic activity. Overexpression of CD36 in cultured microglia rescues the deficit in phagocytosis of myelin debris. By screening for clinically approved agents that stimulate macrophages/microglia, we have found that niacin (vitamin B3) upregulates CD36 expression and enhances myelin phagocytosis by microglia in culture. This increase in myelin phagocytosis is mediated through the niacin receptor (hydroxycarboxylic acid receptor 2). Genetic fate mapping and multiphoton live imaging show that systemic treatment of 9-12-month-old demyelinated mice with therapeutically relevant doses of niacin promotes myelin debris clearance in lesions by both peripherally derived macrophages and microglia. This is accompanied by enhancement of oligodendrocyte progenitor cell numbers and by improved remyelination in the treated mice. Niacin represents a safe and translationally amenable regenerative therapy for chronic demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Khalil S Rawji
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Adam M H Young
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Tanay Ghosh
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Nathan J Michaels
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Reza Mirzaei
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Janson Kappen
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | | | | | - Brian Lozinski
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Manoj K Mishra
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Annie Pu
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Weiwen Tang
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Salma Zein
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Deepak K Kaushik
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | | | | | - Fiona Calvert
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | | | | | | | - Robin J M Franklin
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - V Wee Yong
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada.
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240
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Scheiblich H, Trombly M, Ramirez A, Heneka MT. Neuroimmune Connections in Aging and Neurodegenerative Diseases. Trends Immunol 2020; 41:300-312. [DOI: 10.1016/j.it.2020.02.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 11/26/2022]
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241
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Sutherland TC, Geoffroy CG. The Influence of Neuron-Extrinsic Factors and Aging on Injury Progression and Axonal Repair in the Central Nervous System. Front Cell Dev Biol 2020; 8:190. [PMID: 32269994 PMCID: PMC7109259 DOI: 10.3389/fcell.2020.00190] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/06/2020] [Indexed: 12/21/2022] Open
Abstract
In the aging western population, the average age of incidence for spinal cord injury (SCI) has increased, as has the length of survival of SCI patients. This places great importance on understanding SCI in middle-aged and aging patients. Axon regeneration after injury is an area of study that has received substantial attention and made important experimental progress, however, our understanding of how aging affects this process, and any therapeutic effort to modulate repair, is incomplete. The growth and regeneration of axons is mediated by both neuron intrinsic and extrinsic factors. In this review we explore some of the key extrinsic influences on axon regeneration in the literature, focusing on inflammation and astrogliosis, other cellular responses, components of the extracellular matrix, and myelin proteins. We will describe how each element supports the contention that axonal growth after injury in the central nervous system shows an age-dependent decline, and how this may affect outcomes after a SCI.
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Affiliation(s)
- Theresa C Sutherland
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, United States
| | - Cédric G Geoffroy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, United States
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242
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Erny D, Prinz M. How microbiota shape microglial phenotypes and epigenetics. Glia 2020; 68:1655-1672. [PMID: 32181523 DOI: 10.1002/glia.23822] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 12/17/2022]
Abstract
Among the myeloid cells in the central nervous system (CNS) microglia are the main representatives of the innate immune system. Microglial fulfil tasks beyond phagocytosing debris and host defense against invading microorganism. During brain development microglia guide for example neurons for proper CNS formation, in adulthood they maintain tissue homeostasis and in aging microglia may become pro-inflammatory and finally exhausted. Recently, several endogenous and exogenous factors were identified that essentially shape the microglial phenotype during both steady-state and pathological conditions. On the one hand, microglia receive inputs from CNS-endogenous sources for example, via crosstalk with other glial cells and neurons but on the other hand microglia are also highly modulated by external signals. Among them, host microbiota-the host's resident bacteria-are vital regulators of the CNS innate immune system. This review summarizes key extrinsic and intrinsic factors, with special focus on the host microbiota, that essentially influence microglia functions and states during development, homeostasis, and disease.
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Affiliation(s)
- Daniel Erny
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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243
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Honig MG, Dorian CC, Worthen JD, Micetich AC, Mulder IA, Sanchez KB, Pierce WF, Del Mar NA, Reiner A. Progressive long-term spatial memory loss following repeat concussive and subconcussive brain injury in mice, associated with dorsal hippocampal neuron loss, microglial phenotype shift, and vascular abnormalities. Eur J Neurosci 2020; 54:5844-5879. [PMID: 32090401 PMCID: PMC7483557 DOI: 10.1111/ejn.14711] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 12/14/2022]
Abstract
There is considerable concern about the long‐term deleterious effects of repeat head trauma on cognition, but little is known about underlying mechanisms and pathology. To examine this, we delivered four air blasts to the left side of the mouse cranium, a week apart, with an intensity that causes deficits when delivered singly and considered “concussive,” or an intensity that does not yield significant deficits when delivered singly and considered “subconcussive.” Neither repeat concussive nor subconcussive blast produced spatial memory deficits at 4 months, but both yielded deficits at 14 months, and dorsal hippocampal neuron loss. Hierarchical cluster analysis of dorsal hippocampal microglia across the three groups based on morphology and expression of MHCII, CX3CR1, CD68 and IBA1 revealed five distinct phenotypes. Types 1A and 1B microglia were more common in sham mice, linked to better neuron survival and memory, and appeared mildly activated. By contrast, 2B and 2C microglia were more common in repeat concussive and subconcussive mice, linked to poorer neuron survival and memory, and characterized by low expression levels and attenuated processes, suggesting they were de‐activated and dysfunctional. In addition, endothelial cells in repeat concussive mice exhibited reduced CD31 and eNOS expression, which was correlated with the prevalence of type 2B and 2C microglia. Our findings suggest that both repeat concussive and subconcussive head injury engender progressive pathogenic processes, possibly through sustained effects on microglia that over time lead to increased prevalence of dysfunctional microglia, adversely affecting neurons and blood vessels, and thereby driving neurodegeneration and memory decline.
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Affiliation(s)
- Marcia G Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Conor C Dorian
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - John D Worthen
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Anthony C Micetich
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Isabelle A Mulder
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Katelyn B Sanchez
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - William F Pierce
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN, USA
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244
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Chitu V, Biundo F, Shlager GGL, Park ES, Wang P, Gulinello ME, Gokhan Ş, Ketchum HC, Saha K, DeTure MA, Dickson DW, Wszolek ZK, Zheng D, Croxford AL, Becher B, Sun D, Mehler MF, Stanley ER. Microglial Homeostasis Requires Balanced CSF-1/CSF-2 Receptor Signaling. Cell Rep 2020; 30:3004-3019.e5. [PMID: 32130903 PMCID: PMC7370656 DOI: 10.1016/j.celrep.2020.02.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 12/18/2019] [Accepted: 02/06/2020] [Indexed: 02/08/2023] Open
Abstract
CSF-1R haploinsufficiency causes adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). Previous studies in the Csf1r+/- mouse model of ALSP hypothesized a central role of elevated cerebral Csf2 expression. Here, we show that monoallelic deletion of Csf2 rescues most behavioral deficits and histopathological changes in Csf1r+/- mice by preventing microgliosis and eliminating most microglial transcriptomic alterations, including those indicative of oxidative stress and demyelination. We also show elevation of Csf2 transcripts and of several CSF-2 downstream targets in the brains of ALSP patients, demonstrating that the mechanisms identified in the mouse model are functional in humans. Our data provide insights into the mechanisms underlying ALSP. Because increased CSF2 levels and decreased microglial Csf1r expression have also been reported in Alzheimer's disease and multiple sclerosis, we suggest that the unbalanced CSF-1R/CSF-2 signaling we describe in the present study may contribute to the pathogenesis of other neurodegenerative conditions.
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Affiliation(s)
- Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Fabrizio Biundo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Gabriel G L Shlager
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Eun S Park
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maria E Gulinello
- Behavioral Core Facility, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Şölen Gokhan
- Institute for Brain Disorders and Neural Regeneration, Departments of Neurology, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harmony C Ketchum
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kusumika Saha
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Michael A DeTure
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Deyou Zheng
- The Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, and Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Burkhard Becher
- Institute of Experimental Immunology, University of Zurich, Zurich 8057, Switzerland
| | - Daqian Sun
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Mark F Mehler
- Institute for Brain Disorders and Neural Regeneration, Departments of Neurology, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - E Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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245
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Nugent AA, Lin K, van Lengerich B, Lianoglou S, Przybyla L, Davis SS, Llapashtica C, Wang J, Kim DJ, Xia D, Lucas A, Baskaran S, Haddick PC, Lenser M, Earr TK, Shi J, Dugas JC, Andreone BJ, Logan T, Solanoy HO, Chen H, Srivastava A, Poda SB, Sanchez PE, Watts RJ, Sandmann T, Astarita G, Lewcock JW, Monroe KM, Di Paolo G. TREM2 Regulates Microglial Cholesterol Metabolism upon Chronic Phagocytic Challenge. Neuron 2020; 105:837-854.e9. [DOI: 10.1016/j.neuron.2019.12.007] [Citation(s) in RCA: 207] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 08/07/2019] [Accepted: 12/04/2019] [Indexed: 12/26/2022]
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246
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Joffre C, Dinel AL, Chataigner M, Pallet V, Layé S. n-3 Polyunsaturated Fatty Acids and Their Derivates Reduce Neuroinflammation during Aging. Nutrients 2020; 12:nu12030647. [PMID: 32121189 PMCID: PMC7146513 DOI: 10.3390/nu12030647] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/15/2022] Open
Abstract
: Aging is associated to cognitive decline, which can lead to loss of life quality, personal suffering, and ultimately neurodegenerative diseases. Neuroinflammation is one of the mechanisms explaining the loss of cognitive functions. Indeed, aging is associated to the activation of inflammatory signaling pathways, which can be targeted by specific nutrients with anti-inflammatory effects. Dietary n-3 polyunsaturated fatty acids (PUFAs) are particularly attractive as they are present in the brain, possess immunomodulatory properties, and are precursors of lipid derivates named specialized pro-resolving mediators (SPM). SPMs are crucially involved in the resolution of inflammation that is modified during aging, resulting in chronic inflammation. In this review, we first examine the effect of aging on neuroinflammation and then evaluate the potential beneficial effect of n-3 PUFA as precursors of bioactive derivates, particularly during aging, on the resolution of inflammation. Lastly, we highlight evidence supporting a role of n-3 PUFA during aging.
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Affiliation(s)
- Corinne Joffre
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, 146 rue Léo Saignat, 33076 Bordeaux, France; (M.C.); (V.P.); (S.L.)
- Correspondence:
| | - Anne-Laure Dinel
- NutriBrain Research and Technology Transfer, NutriNeuro, 146 rue Léo Saignat, 33076 Bordeaux, France
| | - Mathilde Chataigner
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, 146 rue Léo Saignat, 33076 Bordeaux, France; (M.C.); (V.P.); (S.L.)
- Abyss Ingredients, 56850 Caudan, France
| | - Véronique Pallet
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, 146 rue Léo Saignat, 33076 Bordeaux, France; (M.C.); (V.P.); (S.L.)
| | - Sophie Layé
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, 146 rue Léo Saignat, 33076 Bordeaux, France; (M.C.); (V.P.); (S.L.)
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247
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Murgoci AN, Duhamel M, Raffo-Romero A, Mallah K, Aboulouard S, Lefebvre C, Kobeissy F, Fournier I, Zilkova M, Maderova D, Cizek M, Cizkova D, Salzet M. Location of neonatal microglia drives small extracellular vesicles content and biological functions in vitro. J Extracell Vesicles 2020; 9:1727637. [PMID: 32158520 PMCID: PMC7049881 DOI: 10.1080/20013078.2020.1727637] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/19/2022] Open
Abstract
Combining proteomics and systems biology approaches, we demonstrate that neonatal microglial cells derived from two different CNS locations, cortex and spinal cord, and cultured in vitro displayed different phenotypes upon different physiological or pathological conditions. These cells also exhibited greater variability in terms of cellular and small extracellular vesicles (sEVs) protein content and levels. Bioinformatic data analysis showed that cortical microglia exerted anti-inflammatory and neurogenesis/tumorigenesis properties, while the spinal cord microglia were more inflammatory. Interestingly, while both sEVs microglia sources enhanced growth of DRGs processes, only the spinal cord-derived sEVs microglia under LPS stimulation significantly attenuated glioma proliferation. These results were confirmed using the neurite outgrowth assay on DRGs cells and glioma proliferation analysis in 3D spheroid cultures. Results from these in vitro assays suggest that the microglia localized at different CNS regions can ensure different biological functions. Together, this study indicates that neonatal microglia locations regulate their physiological and pathological functional fates and could affect the high prevalence of brain vs spinal cord gliomas in adults.
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Affiliation(s)
- Adriana-Natalia Murgoci
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Marie Duhamel
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Antonella Raffo-Romero
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Khalil Mallah
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Soulaimane Aboulouard
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Christophe Lefebvre
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Firas Kobeissy
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Isabelle Fournier
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Monika Zilkova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Denisa Maderova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Milan Cizek
- Department of Epizootiology and Parasitology, University of Veterinary Medicine and Pharmacy in Košice, KošiceSlovakia
| | - Dasa Cizkova
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Michel Salzet
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
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248
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Wang F, Ren SY, Chen JF, Liu K, Li RX, Li ZF, Hu B, Niu JQ, Xiao L, Chan JR, Mei F. Myelin degeneration and diminished myelin renewal contribute to age-related deficits in memory. Nat Neurosci 2020; 23:481-486. [PMID: 32042174 DOI: 10.1038/s41593-020-0588-8] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 01/03/2020] [Indexed: 12/21/2022]
Abstract
Cognitive decline remains an unaddressed problem for the elderly. We show that myelination is highly active in young mice and greatly inhibited in aged mice, coinciding with spatial memory deficits. Inhibiting myelination by deletion of Olig2 in oligodendrocyte precursor cells impairs spatial memory in young mice, while enhancing myelination by deleting the muscarinic acetylcholine receptor 1 in oligodendrocyte precursor cells, or promoting oligodendroglial differentiation and myelination via clemastine treatment, rescues spatial memory decline during aging.
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Affiliation(s)
- Fei Wang
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Shu-Yu Ren
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Jing-Fei Chen
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Kun Liu
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Rui-Xue Li
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Zhi-Fang Li
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China.,Department of Neurology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Bo Hu
- Department of Physiology, Third Military Medical University, Chongqing, China
| | - Jian-Qin Niu
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Lan Xiao
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China
| | - Jonah R Chan
- UCSF Weill Institute for Neurosciences, Department of Neurology, University of California at San Francisco, San Francisco, CA, USA.
| | - Feng Mei
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing, China.
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249
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Vazquez‐Villaseñor I, Garwood CJ, Heath PR, Simpson JE, Ince PG, Wharton SB. Expression of p16 and p21 in the frontal association cortex of ALS/MND brains suggests neuronal cell cycle dysregulation and astrocyte senescence in early stages of the disease. Neuropathol Appl Neurobiol 2020; 46:171-185. [PMID: 31077599 PMCID: PMC7217199 DOI: 10.1111/nan.12559] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 05/11/2019] [Accepted: 05/08/2019] [Indexed: 12/30/2022]
Abstract
AIMS Cellular senescence plays a role in organismal ageing and has been linked to persistent DNA damage in age-related diseases. Brain senescence has been described in astrocytes and microglia, but it is less well understood in neurones. Evidence suggests that neurones activate a senescence-like mechanism that could contribute to neurodegeneration. We aimed to determine whether a persistent DNA damage response (DDR) and senescence activation are features of motor neurone disease (amyotrophic lateral sclerosis, ALS/MND). METHODS We examined expression of senescence (p16 and p21) and DNA damage markers (8-OHdG and γH2AX) in motor cortex (MCx), frontal association cortex (FACx) and occipital cortex (OCx) in post-mortem tissue donated by patients with ALS/MND and controls. RESULTS Nuclear expression of p16 and p21 was detected in glial cells; double immunofluorescence for p16/p21 and glial fibrillary acidic protein (GFAP) suggested that some of these cells were GFAP+ astrocytes. p21 nuclear expression was also found in neurones. Higher levels of p16+ (glia, P = 0.028) and p21+ (glia, P = 0.003; neurones, P = 0.008) cells were found in the FACx of ALS/MND donors but not in the MCx or OCx. Expression of p16 and p21 did not correlate with 8-OHdG or γH2AX. CONCLUSIONS Expression of p16 and p21 in glia, mainly in astrocytes, suggests senescence induction in these cells; however, neuronal p21 expression might reflect a more general mechanism of age-related cell cycle dysregulation. The significantly higher proportion of cells expressing either p16 or p21 in the FACx of ALS/MND donors could indicate senescence activation and cell cycle dysregulation in early stages of the disease.
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Affiliation(s)
- I. Vazquez‐Villaseñor
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - C. J. Garwood
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - P. R. Heath
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - J. E. Simpson
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - P. G. Ince
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - S. B. Wharton
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
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250
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Gosselin D. Epigenomic and transcriptional determinants of microglial cell identity. Glia 2020; 68:1643-1654. [PMID: 31994799 DOI: 10.1002/glia.23787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/08/2020] [Accepted: 01/16/2020] [Indexed: 11/09/2022]
Abstract
Microglia perform multiple tasks that are essential to ensure proper cerebral functions, including synaptic remodeling, clearance of molecular debris, prevention of infections, and so forth. Furthermore, accumulating genetic and pathological evidence implicates microglial cell activity in the etiology of numerous neurodegenerative diseases and psychiatric disorders. Given this, efforts aimed at understanding the molecular mechanisms underlying microglial cell functions hold great potential for the development of novel therapies for various conditions affecting the central nervous system. In that regard, the application of paradigms in epigenomics to study transcription in microglia has provided significant insights into the molecular mechanisms that control the ontogeny and functions of these cells. With a focus on the roles of genomic regulatory elements and the epigenetic marks that control microglial gene expression, we review here recent key advancements in our comprehension of the epigenomic and transcriptional mechanisms that enable microglial cell development and activity.
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Affiliation(s)
- David Gosselin
- Department of Molecular Medicine, Faculty of Medicine, CHU de Québec Research Center, Université Laval, Quebec City, Quebec, Canada
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