201
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Manich G, Gómez-López AR, Almolda B, Villacampa N, Recasens M, Shrivastava K, González B, Castellano B. Differential Roles of TREM2+ Microglia in Anterograde and Retrograde Axonal Injury Models. Front Cell Neurosci 2020; 14:567404. [PMID: 33328887 PMCID: PMC7715005 DOI: 10.3389/fncel.2020.567404] [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: 05/29/2020] [Accepted: 10/14/2020] [Indexed: 11/13/2022] Open
Abstract
Microglia are the main immune cells of the central nervous system (CNS), and they are devoted to the active surveillance of the CNS during homeostasis and disease. In the last years, the microglial receptor Triggering Receptor Expressed on Myeloid cells-2 (TREM2) has been defined to mediate several microglial functions, including phagocytosis, survival, proliferation, and migration, and to be a key regulator of a new common microglial signature induced under neurodegenerative conditions and aging, also known as disease-associated microglia (DAM). Although microglial TREM2 has been mainly studied in chronic neurodegenerative diseases, few studies address its regulation and functions in acute inflammatory injuries. In this context, the present work aims to study the regulation of TREM2 and its functions after reparative axonal injuries, using two-well established animal models of anterograde and retrograde neuronal degeneration: the perforant pathway transection (PPT) and the facial nerve axotomy (FNA). Our results indicate the appearance of a subpopulation of microglia expressing TREM2 after both anterograde and retrograde axonal injury. TREM2+ microglia were not directly related to proliferation, instead, they were associated with specific recognition and/or phagocytosis of myelin and degenerating neurons, as assessed by immunohistochemistry and flow cytometry. Characterization of TREM2+ microglia showed expression of CD16/32, CD68, and occasional Galectin-3. However, specific singularities within each model were observed in P2RY12 expression, which was only downregulated after PPT, and in ApoE, where de novo expression was detected only in TREM2+ microglia after FNA. Finally, we report that the pro-inflammatory or anti-inflammatory cytokine microenvironment, which may affect phagocytosis, did not directly modify the induction of TREM2+ subpopulation in any injury model, although it changed TREM2 levels due to modification of the microglial activation pattern. In conclusion, we describe a unique TREM2+ microglial subpopulation induced after axonal injury, which is directly associated with phagocytosis of specific cell remnants and show different phenotypes, depending on the microglial activation status and the degree of tissue injury.
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Affiliation(s)
- Gemma Manich
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Ariadna Regina Gómez-López
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Beatriz Almolda
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Nàdia Villacampa
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Mireia Recasens
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Kalpana Shrivastava
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Berta González
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Bernardo Castellano
- Department of Cell Biology, Physiology, and Immunology, Institute of Neuroscience, Universitat Autònoma De Barcelona, Barcelona, Spain
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202
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How Repair-or-Dispose Decisions Under Stress Can Initiate Disease Progression. iScience 2020; 23:101701. [PMID: 33235980 PMCID: PMC7670198 DOI: 10.1016/j.isci.2020.101701] [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: 02/07/2020] [Revised: 07/17/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Glia, the helper cells of the brain, are essential in maintaining neural resilience across time and varying challenges: By reacting to changes in neuronal health glia carefully balance repair or disposal of injured neurons. Malfunction of these interactions is implicated in many neurodegenerative diseases. We present a reductionist model that mimics repair-or-dispose decisions to generate a hypothesis for the cause of disease onset. The model assumes four tissue states: healthy and challenged tissue, primed tissue at risk of acute damage propagation, and chronic neurodegeneration. We discuss analogies to progression stages observed in the most common neurodegenerative conditions and to experimental observations of cellular signaling pathways of glia-neuron crosstalk. The model suggests that the onset of neurodegeneration can result as a compromise between two conflicting goals: short-term resilience to stressors versus long-term prevention of tissue damage.
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203
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Picca A, Guerra F, Calvani R, Coelho-Júnior HJ, Landi F, Bernabei R, Romano R, Bucci C, Marzetti E. Extracellular Vesicles and Damage-Associated Molecular Patterns: A Pandora's Box in Health and Disease. Front Immunol 2020; 11:601740. [PMID: 33304353 PMCID: PMC7701251 DOI: 10.3389/fimmu.2020.601740] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
Sterile inflammation develops as part of an innate immunity response to molecules released upon tissue injury and collectively indicated as damage-associated molecular patterns (DAMPs). While coordinating the clearance of potential harmful stimuli, promotion of tissue repair, and restoration of tissue homeostasis, a hyper-activation of such an inflammatory response may be detrimental. The complex regulatory pathways modulating DAMPs generation and trafficking are actively investigated for their potential to provide relevant insights into physiological and pathological conditions. Abnormal circulating extracellular vesicles (EVs) stemming from altered endosomal-lysosomal system have also been reported in several age-related conditions, including cancer and neurodegeneration, and indicated as a promising route for therapeutic purposes. Along this pathway, mitochondria may dispose altered components to preserve organelle homeostasis. However, whether a common thread exists between DAMPs and EVs generation is yet to be clarified. A deeper understanding of the highly complex, dynamic, and variable intracellular and extracellular trafficking of DAMPs and EVs, including those of mitochondrial origin, is needed to unveil relevant pathogenic pathways and novel targets for drug development. Herein, we describe the mechanisms of generation of EVs and mitochondrial-derived vesicles along the endocytic pathway and discuss the involvement of the endosomal-lysosomal in cancer and neurodegeneration (i.e., Alzheimer's and Parkinson's disease).
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Affiliation(s)
- Anna Picca
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Flora Guerra
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Riccardo Calvani
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | | | - Francesco Landi
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Roberto Bernabei
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Roberta Romano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Emanuele Marzetti
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
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204
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Barros C, Fernandes A. Linking Cognitive Impairment to Neuroinflammation in Multiple Sclerosis using neuroimaging tools. Mult Scler Relat Disord 2020; 47:102622. [PMID: 33227630 DOI: 10.1016/j.msard.2020.102622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/24/2022]
Abstract
Multiple sclerosis (MS) is a complex chronic immune disease in the central nervous system, causing neurological disability among young and middle-aged adults. Impaired cognition is now emerging as a major clinical symptom being present in more than 50% of MS patients. Recent data support that neuroinflammation mediated by glial cells plays a key part in MS course and, particularly, microglia is responsible for the pruning of synapses possibly impacting on vital neural networks maintenance. However, the knowledge of microglia-mediated mechanisms underlying cognitive impairment in MS is poor and unfortunately, there are no medicines to overcome this "invisible" symptom. Interestingly, the use of powerful diagnostic imaging tools as structural and functional MRI as well as PET brought new insights into some biological mechanisms, but no link between the possibility to use early visible alterations to predict cognitive deficits was clarified yet. In this review, we focus on the interplay between MS-related cognitive structures and neuroinflammation, specifically the presence of microglia and their reactivity. Moreover, we also discuss new imaging tools to assess cognitive impairment and to track microglia activation. Understanding the role of microglia in cognitive impairment and how it can be prevented may be a promising contribution to innovative therapeutic strategies that culminate in the improvement of MS patients' life quality.
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Affiliation(s)
- Catarina Barros
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal
| | - Adelaide Fernandes
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal; Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Portugal.
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205
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Boi L, Pisanu A, Palmas MF, Fusco G, Carboni E, Casu MA, Satta V, Scherma M, Janda E, Mocci I, Mulas G, Ena A, Spiga S, Fadda P, De Simone A, Carta AR. Modeling Parkinson's Disease Neuropathology and Symptoms by Intranigral Inoculation of Preformed Human α-Synuclein Oligomers. Int J Mol Sci 2020; 21:E8535. [PMID: 33198335 PMCID: PMC7696693 DOI: 10.3390/ijms21228535] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/21/2022] Open
Abstract
The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson's disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies.
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Affiliation(s)
- Laura Boi
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | | | - Maria Francesca Palmas
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | - Giuliana Fusco
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, UK;
| | - Ezio Carboni
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | - Maria Antonietta Casu
- CNR Institute of Translational Pharmacology, 09010 Cagliari, Italy; (M.A.C.); (I.M.)
| | - Valentina Satta
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | - Maria Scherma
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | - Elzbieta Janda
- Department of Health Sciences, Magna Graecia University, 88100 Catanzaro, Italy;
| | - Ignazia Mocci
- CNR Institute of Translational Pharmacology, 09010 Cagliari, Italy; (M.A.C.); (I.M.)
| | - Giovanna Mulas
- Department of Life and Environmental Sciences, University of Cagliari, 09126 Cagliari, Italy; (G.M.); (S.S.)
| | - Anna Ena
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
| | - Saturnino Spiga
- Department of Life and Environmental Sciences, University of Cagliari, 09126 Cagliari, Italy; (G.M.); (S.S.)
| | - Paola Fadda
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
- CNR Institute of Neuroscience, 09042 Cagliari, Italy;
- Italian Neuroscience Institute (INN), 10126 Torino, Italy
| | - Alfonso De Simone
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Department of Pharmacy, University of Naples “Federico II”, 80131 Naples, Italy
| | - Anna R. Carta
- Department of Biomedical Sciences, University of Cagliari, 09042 Cagliari, Italy; (L.B.); (M.F.P.); (E.C.); (V.S.); (M.S.); (A.E.); (P.F.)
- Italian Neuroscience Institute (INN), 10126 Torino, Italy
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206
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Jeon YM, Kwon Y, Jo M, Lee S, Kim S, Kim HJ. The Role of Glial Mitochondria in α-Synuclein Toxicity. Front Cell Dev Biol 2020; 8:548283. [PMID: 33262983 PMCID: PMC7686475 DOI: 10.3389/fcell.2020.548283] [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: 08/13/2020] [Accepted: 10/20/2020] [Indexed: 12/18/2022] Open
Abstract
The abnormal accumulation of alpha-synuclein (α-syn) aggregates in neurons and glial cells is widely known to be associated with many neurodegenerative diseases, including Parkinson's disease (PD), Dementia with Lewy bodies (DLB), and Multiple system atrophy (MSA). Mitochondrial dysfunction in neurons and glia is known as a key feature of α-syn toxicity. Studies aimed at understanding α-syn-induced toxicity and its role in neurodegenerative diseases have primarily focused on neurons. However, a growing body of evidence demonstrates that glial cells such as microglia and astrocytes have been implicated in the initial pathogenesis and the progression of α-Synucleinopathy. Glial cells are important for supporting neuronal survival, synaptic functions, and local immunity. Furthermore, recent studies highlight the role of mitochondrial metabolism in the normal function of glial cells. In this work, we review the complex relationship between glial mitochondria and α-syn-mediated neurodegeneration, which may provide novel insights into the roles of glial cells in α-syn-associated neurodegenerative diseases.
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Affiliation(s)
- Yu-Mi Jeon
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Younghwi Kwon
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
- Department of Brain and Cognitive Sciences, DGIST, Daegu, South Korea
| | - Myungjin Jo
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Shinrye Lee
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Seyeon Kim
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
- Department of Brain and Cognitive Sciences, DGIST, Daegu, South Korea
| | - Hyung-Jun Kim
- Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea
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207
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Wu S, Romero-Ramírez L, Mey J. Retinoic acid increases phagocytosis of myelin by macrophages. J Cell Physiol 2020; 236:3929-3945. [PMID: 33165955 PMCID: PMC7984038 DOI: 10.1002/jcp.30137] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/28/2022]
Abstract
Traumatic injuries of the central nervous system (CNS) are followed by the accumulation of cellular debris including proteins and lipids from myelinated fiber tracts. Insufficient phagocytic clearance of myelin debris influences the pathological process because it induces inflammation and blocks axonal regeneration. We investigated whether ligands of nuclear receptor families retinoic acid receptors (RARs), retinoid X receptors, peroxisome proliferator-activated receptors, lipid X receptors, and farnesoid X receptors increase myelin phagocytosis by murine bone marrow-derived macrophages and Raw264.7 cells. Using in vitro assays with 3,3'-dioctadecyloxacarbocyanine perchlorate- and pHrodo-labeled myelin we found that the transcriptional activator all-trans retinoic acid (RA)enhanced endocytosis of myelin involving the induction of tissue transglutaminase-2. The RAR-dependent increase of phagocytosis was not associated with changes in gene expression of receptors FcγR1, FcγR2b, FcγR3, TREM2, DAP12, CR3, or MerTK. The combination of RA and myelin exposure significantly reduced the expression of M1 marker genes inducible nitric oxide synthase and interleukin-1β and increased expression of transmembrane proteins CD36 and ABC-A1, which are involved in lipid transport and metabolism. The present results suggest an additional mechanism for therapeutic applications of RA after CNS trauma. It remains to be studied whether endogenous RA-signaling regulates phagocytosis in vivo.
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Affiliation(s)
- Siyu Wu
- Laboratorio Regeneración Neuronal e Inmunidad Innata, Hospital Nacional de Parapléjicos, Toledo, Spain.,School of Mental Health and Neuroscience and EURON Graduate School of Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Lorenzo Romero-Ramírez
- Laboratorio Regeneración Neuronal e Inmunidad Innata, Hospital Nacional de Parapléjicos, Toledo, Spain
| | - Jörg Mey
- Laboratorio Regeneración Neuronal e Inmunidad Innata, Hospital Nacional de Parapléjicos, Toledo, Spain.,School of Mental Health and Neuroscience and EURON Graduate School of Neuroscience, Maastricht University, Maastricht, The Netherlands
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208
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Scalabrino G. Epidermal Growth Factor in the CNS: A Beguiling Journey from Integrated Cell Biology to Multiple Sclerosis. An Extensive Translational Overview. Cell Mol Neurobiol 2020; 42:891-916. [PMID: 33151415 PMCID: PMC8942922 DOI: 10.1007/s10571-020-00989-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/23/2020] [Indexed: 12/16/2022]
Abstract
This article reviews the wealth of papers dealing with the different effects of epidermal growth factor (EGF) on oligodendrocytes, astrocytes, neurons, and neural stem cells (NSCs). EGF induces the in vitro and in vivo proliferation of NSCs, their migration, and their differentiation towards the neuroglial cell line. It interacts with extracellular matrix components. NSCs are distributed in different CNS areas, serve as a reservoir of multipotent cells, and may be increased during CNS demyelinating diseases. EGF has pleiotropic differentiative and proliferative effects on the main CNS cell types, particularly oligodendrocytes and their precursors, and astrocytes. EGF mediates the in vivo myelinotrophic effect of cobalamin on the CNS, and modulates the synthesis and levels of CNS normal prions (PrPCs), both of which are indispensable for myelinogenesis and myelin maintenance. EGF levels are significantly lower in the cerebrospinal fluid and spinal cord of patients with multiple sclerosis (MS), which probably explains remyelination failure, also because of the EGF marginal role in immunology. When repeatedly administered, EGF protects mouse spinal cord from demyelination in various experimental models of autoimmune encephalomyelitis. It would be worth further investigating the role of EGF in the pathogenesis of MS because of its multifarious effects.
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Affiliation(s)
- Giuseppe Scalabrino
- Department of Biomedical Sciences, University of Milan, Via Mangiagalli 31, 20133, Milan, Italy.
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209
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Wang X, Tong Y, Zhang J, Khan N, Zhang K, Bai H, Zhang Q, Chen Y. Neuroinflammation changes with periodontal inflammation status during periodontitis in wild-type mice. Oral Dis 2020; 27:1001-1011. [PMID: 32815656 DOI: 10.1111/odi.13618] [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] [Received: 11/22/2019] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To investigate neuroinflammation under different periodontal status. MATERIALS AND METHODS Experimental periodontitis was induced by molar ligation (Lig group) or periodontal injection of lipopolysaccharide (LPS, Lps group). Periodontal status was assessed by alveolar bone resorption and periodontal inflammation. Micro-computed tomography and haematoxylin-eosin staining were performed to assess alveolar bone resorption and periodontal inflammation, respectively. Neuroinflammation was assessed by glial cell proliferation and proinflammatory factor expression. Microgliosis was determined by immunofluorescence. Astrogliosis was determined by immunohistochemistry. Expressions of tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-1β were assessed by enzyme-linked immunosorbent assay. RESULTS Microgliosis and astrogliosis in the Lig group were notable with molar ligation for 2 weeks and 4 weeks (p < .05), but were only slightly different similar from the control group by week 12. Microgliosis and astrogliosis in the Lps group were significant with LPS injection for 4 and 8 weeks (p < .05). The groups displayed a positive correlation between the degree of periodontal inflammation and the number of glial cells (p < .05). Expressions of IL-1β and TNF-α in the Lps group were significantly increased with LPS injection for 8 weeks (p < .05). In the Lig group, only TNF-α was highly expressed with molar ligation for 12 weeks (p < .05). CONCLUSION Both models demonstrated that the inflammatory response in the hippocampus of mice can change during periodontitis depending on the periodontal inflammation status.
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Affiliation(s)
- Xu Wang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | - Yuxin Tong
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | - Jiayu Zhang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | - Nazia Khan
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | - Kaili Zhang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | - Huihui Bai
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
| | | | - Yue Chen
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Xi'an Jiaotong University, Xi'an, China
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210
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Abstract
The innate immune system in the central nervous system (CNS) is mainly represented by specialized tissue-resident macrophages, called microglia. In the past years, various species-, host- and tissue-specific as well as environmental factors were recognized that essentially affect microglial properties and functions in the healthy and diseased brain. Host microbiota are mostly residing in the gut and contribute to microglial activation states, for example, via short-chain fatty acids (SCFAs) or aryl hydrocarbon receptor (AhR) ligands. Thereby, the gut microorganisms are deemed to influence numerous CNS diseases mediated by microglia. In this review, we summarize recent findings of the interaction between the host microbiota and the CNS in health and disease, where we specifically highlight the resident gut microbiota as a crucial environmental factor for microglial function as what we coin "the microbiota-microglia axis."
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Affiliation(s)
- Omar Mossad
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
- Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Daniel Erny
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
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211
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Jadhav VS, Lin PBC, Pennington T, Di Prisco GV, Jannu AJ, Xu G, Moutinho M, Zhang J, Atwood BK, Puntambekar SS, Bissel SJ, Oblak AL, Landreth GE, Lamb BT. Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice. Mol Neurodegener 2020; 15:62. [PMID: 33115519 PMCID: PMC7594478 DOI: 10.1186/s13024-020-00409-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/01/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer's disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer's disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia. METHODS To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2-/- mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches. RESULTS While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2-/- mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. CONCLUSION Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.
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Affiliation(s)
- Vaishnavi S Jadhav
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Peter B C Lin
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Taylor Pennington
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Gonzalo Viana Di Prisco
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Asha Jacob Jannu
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 462020, USA
| | - Guixiang Xu
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Miguel Moutinho
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Anatomy and Cell Biology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Jie Zhang
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Brady K Atwood
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Shweta S Puntambekar
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Stephanie J Bissel
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Adrian L Oblak
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Radiology & Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Gary E Landreth
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Anatomy and Cell Biology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Bruce T Lamb
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA.
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Delage CI, Cornil CA. Estrogen‐dependent sex difference in microglia in the developing brain of Japanese quail (
Coturnix japonica
). Dev Neurobiol 2020; 80:239-262. [DOI: 10.1002/dneu.22781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 12/26/2022]
Affiliation(s)
| | - Charlotte Anne Cornil
- Laboratory of Neuroendocrinology GIGA Neurosciences University of Liège Liège Belgium
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213
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Guo J, Zhang XLN, Bao ZR, Yang XK, Li LS, Zi Y, Li F, Wu CY, Li JJ, Yuan Y. Gastrodin Regulates the Notch Signaling Pathway and Sirt3 in Activated Microglia in Cerebral Hypoxic-Ischemia Neonatal Rats and in Activated BV-2 Microglia. Neuromolecular Med 2020; 23:348-362. [PMID: 33095377 DOI: 10.1007/s12017-020-08627-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/16/2020] [Indexed: 12/13/2022]
Abstract
In response to hypoxic-ischemic brain damage (HIBD), microglia activation and its mediated inflammation contribute to neuronal damage. Inhibition of over-activated microglia is deemed to be a potential therapeutic strategy. Our previous studies showed that gastrodin efficiently depressed the neuroinflammation mediated by activated microglia in HIBD neonatal rats. The underlying mechanisms through which gastrodin acts on activated microglia have not been fully elucidated. This study is designed to determine whether gastrodin would regulate the Notch signaling pathway and Sirtuin3 (Sirt3), which are implicated in regulating microglia activation. The present results showed that gastrodin markedly suppressed the expression of members of Notch signaling pathway (Notch-1, NICD, RBP-JK and Hes-1) in activated microglia both in vivo and in vitro. Conversely, Sirt3 expression was enhanced. In BV-2 microglia treated with a γ-secretase inhibitor of Notch pathway- DAPT, the expression of RBP-JK, Hes-1, and NICD was suppressed in activated microglia. Treatment with DAPT and gastrodin further decreased NICD and Hes-1 expression. Sirt3 expression was also decreased after DAPT treatment. However, Sirt3 expression in activated BV-2 microglia given a combined DAPT and gastrodin treatment was not further increased. In addition, combination of DAPT and Gastrodin cumulatively decreased tumor necrosis factor-α (TNF-α) expression. The results suggest that gastrodin regulates microglia activation via the Notch signaling pathway and Sirt3. More importantly, interference of the Notch signaling pathway inhibited Sirt3 expression, indicating that Sirt3 is a downstream gene of the Notch signaling pathway. It is suggested that Notch and Sirt3 synergistically regulate microglia activation such as in TNF-α production.
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MESH Headings
- Animals
- Animals, Newborn
- Benzyl Alcohols/pharmacokinetics
- Benzyl Alcohols/pharmacology
- Carotid Artery, Common
- Cells, Cultured
- Cerebral Cortex/pathology
- Corpus Callosum/pathology
- Diamines/pharmacology
- Disease Models, Animal
- Drug Synergism
- Gene Expression Regulation/drug effects
- Glucosides/pharmacokinetics
- Glucosides/pharmacology
- Hypoxia-Ischemia, Brain/drug therapy
- Hypoxia-Ischemia, Brain/metabolism
- Hypoxia-Ischemia, Brain/pathology
- Ligation
- Lipopolysaccharides/pharmacology
- Microglia/drug effects
- Microglia/metabolism
- Neuroinflammatory Diseases/drug therapy
- Random Allocation
- Rats
- Rats, Sprague-Dawley
- Receptor, Notch1/biosynthesis
- Receptor, Notch1/genetics
- Receptor, Notch1/physiology
- Signal Transduction/drug effects
- Sirtuins/biosynthesis
- Sirtuins/genetics
- Sirtuins/physiology
- Thiazoles/pharmacology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/genetics
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Affiliation(s)
- Jing Guo
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Xiao-Li-Na Zhang
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
- First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650500, China
| | - Zhang-Rui Bao
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Xue-Ke Yang
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Ling-Shuang Li
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Yu Zi
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Fan Li
- Department of Pathology and Pathophysiology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Chun-Yun Wu
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China
| | - Juan-Juan Li
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China.
| | - Yun Yuan
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, China.
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214
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Lang GP, Ndongson-Dongmo B, Lajqi T, Brodhun M, Han Y, Wetzker R, Frasch MG, Bauer R. Impact of ambient temperature on inflammation-induced encephalopathy in endotoxemic mice-role of phosphoinositide 3-kinase gamma. J Neuroinflammation 2020; 17:292. [PMID: 33028343 PMCID: PMC7541275 DOI: 10.1186/s12974-020-01954-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sepsis-associated encephalopathy (SAE) is an early and frequent event of infection-induced systemic inflammatory response syndrome. Phosphoinositide 3-kinase γ (PI3Kγ) is linked to neuroinflammation and inflammation-related microglial activity. In homeotherms, variations in ambient temperature (Ta) outside the thermoneutral zone lead to thermoregulatory responses, mainly driven by a gradually increasing sympathetic activity, and may affect disease severity. We hypothesized that thermoregulatory response to hypothermia (reduced Ta) aggravates SAE in PI3Kγ-dependent manner. METHODS Experiments were performed in wild-type, PI3Kγ knockout, and PI3Kγ kinase-dead mice, which were kept at neutral (30 ± 0.5 °C) or moderately lowered (26 ± 0.5 °C) Ta. Mice were exposed to lipopolysaccharide (LPS, 10 μg/g, from Escherichia coli serotype 055:B5, single intraperitoneal injection)-evoked systemic inflammatory response (SIR) and monitored 24 h for thermoregulatory response and blood-brain barrier integrity. Primary microglial cells and brain tissue derived from treated mice were analyzed for inflammatory responses and related cell functions. Comparisons between groups were made with one-way or two-way analysis of variance, as appropriate. Post hoc comparisons were made with the Holm-Sidak test or t tests with Bonferroni's correction for adjustments of multiple comparisons. Data not following normal distribution was tested with Kruskal-Wallis test followed by Dunn's multiple comparisons test. RESULTS We show that a moderate reduction of ambient temperature triggers enhanced hypothermia of mice undergoing LPS-induced systemic inflammation by aggravated SAE. PI3Kγ deficiency enhances blood-brain barrier injury and upregulation of matrix metalloproteinases (MMPs) as well as an impaired microglial phagocytic activity. CONCLUSIONS Thermoregulatory adaptation in response to ambient temperatures below the thermoneutral range exacerbates LPS-induced blood-brain barrier injury and neuroinflammation. PI3Kγ serves a protective role in suppressing release of MMPs, maintaining microglial motility and reinforcing phagocytosis leading to improved brain tissue integrity. Thus, preclinical research targeting severe brain inflammation responses is seriously biased when basic physiological prerequisites of mammal species such as preferred ambient temperature are ignored.
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Affiliation(s)
- Guang-Ping Lang
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Joint International Research Laboratory of Ethnomedicine and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, 563006 China
| | - Bernadin Ndongson-Dongmo
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Trim Lajqi
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
- Department of Neonatology, University Children’s Hospital, Heidelberg, Germany
| | - Michael Brodhun
- Department of Pathology, Helios-Klinikum Erfurt, Erfurt, Germany
| | - Yingying Han
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, 60590 Frankfurt, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | | | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Hans-Knöll-Straße 2, D-07745 Jena, Germany
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215
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Peli1 impairs microglial Aβ phagocytosis through promoting C/EBPβ degradation. PLoS Biol 2020; 18:e3000837. [PMID: 33017390 PMCID: PMC7561136 DOI: 10.1371/journal.pbio.3000837] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 10/15/2020] [Accepted: 08/26/2020] [Indexed: 12/29/2022] Open
Abstract
Amyloid-β (Aβ) accumulation in the brain is a hallmark of Alzheimer’s disease (AD) pathology. However, the molecular mechanism controlling microglial Aβ phagocytosis is poorly understood. Here we found that the E3 ubiquitin ligase Pellino 1 (Peli1) is induced in the microglia of AD-like five familial AD (5×FAD) mice, whose phagocytic efficiency for Aβ was then impaired, and therefore Peli1 depletion suppressed the Aβ deposition in the brains of 5×FAD mice. Mechanistic characterizations indicated that Peli1 directly targeted CCAAT/enhancer-binding protein (C/EBP)β, a major transcription factor responsible for the transcription of scavenger receptor CD36. Peli1 functioned as a direct E3 ubiquitin ligase of C/EBPβ and mediated its ubiquitination-induced degradation. Consequently, loss of Peli1 increased the protein levels of C/EBPβ and the expression of CD36 and thus, promoted the phagocytic ability in microglial cells. Together, our findings established Peli1 as a critical regulator of microglial phagocytosis and highlighted the therapeutic potential by targeting Peli1 for the treatment of microglia-mediated neurological diseases. This study identifies Peli1, an E3 ubiqitin ligase enriched in microglia, as a restraining factor that curtails microglial phagocytosis of the amyloid Aβ. Correspondingly, deletion of Peli1 enhances Aβ phagocytosis and clearance in Alzheimer’s disease, implicating Peli1 as a therapeutic target with significant potential for the treatment of microglia-mediated neurological disease.
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216
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Cignarella F, Filipello F, Bollman B, Cantoni C, Locca A, Mikesell R, Manis M, Ibrahim A, Deng L, Benitez BA, Cruchaga C, Licastro D, Mihindukulasuriya K, Harari O, Buckland M, Holtzman DM, Rosenthal A, Schwabe T, Tassi I, Piccio L. TREM2 activation on microglia promotes myelin debris clearance and remyelination in a model of multiple sclerosis. Acta Neuropathol 2020; 140:513-534. [PMID: 32772264 PMCID: PMC7498497 DOI: 10.1007/s00401-020-02193-z] [Citation(s) in RCA: 171] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 01/13/2023]
Abstract
Multiple sclerosis (MS) is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS) triggered by autoimmune mechanisms. Microglia are critical for the clearance of myelin debris in areas of demyelination, a key step to allow remyelination. TREM2 is expressed by microglia and promotes microglial survival, proliferation, and phagocytic activity. Herein we demonstrate that TREM2 was highly expressed on myelin-laden phagocytes in active demyelinating lesions in the CNS of subjects with MS. In gene expression studies, macrophages from subjects with TREM2 genetic deficiency displayed a defect in phagocytic pathways. Treatment with a new TREM2 agonistic antibody promoted the clearance of myelin debris in the cuprizone model of CNS demyelination. Effects included enhancement of myelin uptake and degradation, resulting in accelerated myelin debris removal by microglia. Most importantly, antibody-dependent TREM2 activation on microglia increased density of oligodendrocyte precursors in areas of demyelination, as well as the formation of mature oligodendrocytes thus enhancing remyelination and axonal integrity. These results are relevant as they propose TREM2 on microglia as a potential new target to promote remyelination.
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Affiliation(s)
- Francesca Cignarella
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
- Alector, 131 Oyster Point Blvd #600, South San Francisco, CA, 94080, USA
| | - Fabia Filipello
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele - Milan, 20090, Italy
| | - Bryan Bollman
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
| | - Claudia Cantoni
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
| | - Alberto Locca
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
| | - Robert Mikesell
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
| | - Melissa Manis
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
| | - Adiljan Ibrahim
- Alector, 131 Oyster Point Blvd #600, South San Francisco, CA, 94080, USA
| | - Li Deng
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Bruno A Benitez
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Danilo Licastro
- ARGO Open Lab Platform for Genome sequencing, AREA Science Park, Padriciano 99, 34149, Trieste, Italy
| | - Kathie Mihindukulasuriya
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Oscar Harari
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Michael Buckland
- Brain and Mind Centre, University of Sydney, 94 Mallett St Camperdown, Sydney, NSW, 2050, Australia
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Arnon Rosenthal
- Alector, 131 Oyster Point Blvd #600, South San Francisco, CA, 94080, USA
| | - Tina Schwabe
- Alector, 131 Oyster Point Blvd #600, South San Francisco, CA, 94080, USA
| | - Ilaria Tassi
- Alector, 131 Oyster Point Blvd #600, South San Francisco, CA, 94080, USA.
| | - Laura Piccio
- Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA.
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Brain and Mind Centre, University of Sydney, 94 Mallett St Camperdown, Sydney, NSW, 2050, Australia.
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217
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Sariol A, Mackin S, Allred MG, Ma C, Zhou Y, Zhang Q, Zou X, Abrahante JE, Meyerholz DK, Perlman S. Microglia depletion exacerbates demyelination and impairs remyelination in a neurotropic coronavirus infection. Proc Natl Acad Sci U S A 2020; 117:24464-24474. [PMID: 32929007 PMCID: PMC7533697 DOI: 10.1073/pnas.2007814117] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microglia are considered both pathogenic and protective during recovery from demyelination, but their precise role remains ill defined. Here, using an inhibitor of colony stimulating factor 1 receptor (CSF1R), PLX5622, and mice infected with a neurotropic coronavirus (mouse hepatitis virus [MHV], strain JHMV), we show that depletion of microglia during the time of JHMV clearance resulted in impaired myelin repair and prolonged clinical disease without affecting the kinetics of virus clearance. Microglia were required only during the early stages of remyelination. Notably, large deposits of extracellular vesiculated myelin and cellular debris were detected in the spinal cords of PLX5622-treated and not control mice, which correlated with decreased numbers of oligodendrocytes in demyelinating lesions in drug-treated mice. Furthermore, gene expression analyses demonstrated differential expression of genes involved in myelin debris clearance, lipid and cholesterol recycling, and promotion of oligodendrocyte function. The results also demonstrate that microglial functions affected by depletion could not be compensated by infiltrating macrophages. Together, these results demonstrate that microglia play key roles in debris clearance and in the initiation of remyelination following infection with a neurotropic coronavirus but are not necessary during later stages of remyelination.
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Affiliation(s)
- Alan Sariol
- Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242
| | - Samantha Mackin
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242
| | - Merri-Grace Allred
- Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242
| | - Chen Ma
- School of Mathematics and Statistics, Wuhan University, 430072 Wuhan, China
| | - Yu Zhou
- School of Mathematics and Statistics, Wuhan University, 430072 Wuhan, China
| | - Qinran Zhang
- School of Mathematics and Statistics, Wuhan University, 430072 Wuhan, China
| | - Xiufen Zou
- School of Mathematics and Statistics, Wuhan University, 430072 Wuhan, China
| | - Juan E Abrahante
- University of Minnesota Informatics Institute (UMII), Minneapolis, MN 55455
| | | | - Stanley Perlman
- Interdisciplinary Program in Immunology, University of Iowa, Iowa City, IA 52242;
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242
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218
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Abstract
The central nervous system is simply divided into two distinct anatomical regions based on the color of tissues, i.e. the gray and white matter. The gray matter is composed of neuronal cell bodies, glial cells, dendrites, immune cells, and the vascular system, while the white matter is composed of concentrated myelinated axonal fibers extending from neuronal soma and glial cells, such as oligodendrocyte precursor cells (OPCs), oligodendrocytes, astrocytes, and microglia. As neuronal cell bodies are located in the gray matter, great attention has been focused mainly on the gray matter regarding the understanding of the functions of the brain throughout the neurophysiological areas, leading to a scenario in which the function of the white matter is relatively underestimated or has not received much attention. However, increasing evidence shows that the white matter plays highly significant and pivotal functions in the brain based on the fact that its abnormalities are associated with numerous neurological diseases. In this review, we will broadly discuss the pathways and functions of myelination, which is one of the main processes that modulate the functions of the white matter, as well as the manner in which its abnormalities are related to neurological disorders.
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219
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Pons V, Rivest S. Beneficial Roles of Microglia and Growth Factors in MS, a Brief Review. Front Cell Neurosci 2020; 14:284. [PMID: 33173466 PMCID: PMC7538672 DOI: 10.3389/fncel.2020.00284] [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: 05/20/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022] Open
Abstract
Microglia are the brain resident immune cells; they can produce a large variety of growth factors (GFs) to prevent neuronal damages and promote recovery. In neurodegenerative diseases, microglia can play both benefic and deleterious roles, depending on different factors and disease context. In multiple sclerosis, microglia are involved in both demyelination (DM) and remyelination (RM) processes. Recent studies suggest a beneficial role of microglia in regenerative processes. These include the regenerative development of myelin after DM. This review gives an overlook of how microglia and GFs can influence the RM properties.
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Affiliation(s)
- Vincent Pons
- Neuroscience Laboratory, Department of Molecular Medicine, Faculty of Medicine, CHU de Québec Research Center, Laval University, Québec City, QC, Canada
| | - Serge Rivest
- Neuroscience Laboratory, Department of Molecular Medicine, Faculty of Medicine, CHU de Québec Research Center, Laval University, Québec City, QC, Canada
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220
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Shibahara T, Ago T, Tachibana M, Nakamura K, Yamanaka K, Kuroda J, Wakisaka Y, Kitazono T. Reciprocal Interaction Between Pericytes and Macrophage in Poststroke Tissue Repair and Functional Recovery. Stroke 2020; 51:3095-3106. [PMID: 32933419 DOI: 10.1161/strokeaha.120.029827] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Poststroke tissue repair, comprised of macrophage-mediated clearance of myelin debris and pericyte-mediated fibrotic response within the infarct area, is an important process for functional recovery. Herein, we investigated the reciprocal interaction between pericytes and macrophages during poststroke repair and functional recovery. METHODS We performed a permanent middle cerebral artery occlusion in both wild-type and pericyte-deficient PDGFRβ (platelet-derived growth factor receptor β) heterozygous knockout (Pdgfrb+/-) mice and compared histological changes and neurological functions between the 2 groups. We also examined the effects of conditioned medium harvested from cultured pericytes, or bone marrow-derived macrophages, on the functions of other cell types. RESULTS Localization of PDGFRβ-positive pericytes and F4/80-positive macrophages was temporally and spatially very similar following permanent middle cerebral artery occlusion. Intrainfarct accumulation of macrophages was significantly attenuated in Pdgfrb+/- mice. Intrainfarct pericytes expressed CCL2 (C-C motif ligand 2) and CSF1 (colony stimulating factor 1), both of which were significantly lower in Pdgfrb+/- mice. Cultured pericytes expressed Ccl2 and Csf1, both of which were significantly increased by PDGF-BB and suppressed by a PDGFRβ inhibitor. Pericyte conditioned medium significantly enhanced migration and proliferation of bone marrow-derived macrophages. Poststroke clearance of myelin debris was significantly attenuated in Pdgfrb+/- mice. Pericyte conditioned medium promoted phagocytic activity in bone marrow-derived macrophages, also enhancing both STAT3 (signal transducer and activator of transcription 3) phosphorylation and expression of scavenger receptors, Msr1 and Lrp1. Macrophages processing myelin debris produced trophic factors, enhancing PDGFRβ signaling in pericytes leading to the production of ECM (extracellular matrix) proteins and oligodendrogenesis. Functional recovery was significantly attenuated in Pdgfrb+/- mice, parallel with the extent of tissue repair. CONCLUSIONS A reciprocal interaction between pericytes and macrophages is important for poststroke tissue repair and functional recovery.
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Affiliation(s)
- Tomoya Shibahara
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Tetsuro Ago
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Masaki Tachibana
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Kuniyuki Nakamura
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Kei Yamanaka
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Junya Kuroda
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Yoshinobu Wakisaka
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Takanari Kitazono
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Japan
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Teixeira-Pinheiro LC, Toledo MF, Nascimento-Dos-Santos G, Mendez-Otero R, Mesentier-Louro LA, Santiago MF. Paracrine signaling of human mesenchymal stem cell modulates retinal microglia population number and phenotype in vitro. Exp Eye Res 2020; 200:108212. [PMID: 32910940 DOI: 10.1016/j.exer.2020.108212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/13/2020] [Accepted: 08/31/2020] [Indexed: 01/13/2023]
Abstract
PURPOSE Cellular therapy with mesenchymal stem cells (MSC) is emerging as an effective option to treat optic neuropathies. In models of retinal degeneration, MSC injected in the vitreous body protects injured retinal ganglion cells and stimulate their regeneration, however the mechanism is still unknown. Considering the immunomodulating proprieties of MSC and the controversial role of microglial contribution on retinal regeneration, we developed an in vitro co-culture model to analyze the effect of MSC on retinal microglia population. METHODS We used whole adult rat retinal explants in co-culture with human Wharton's jelly mesenchymal stem cells (hMSC) separated by a transwell membrane and analyzed hMSC effect on both retinal ganglion cells (RGCs) and retinal microglia. RESULTS hMSC in co-culture protected RGCs after 3 days in vitro by paracrine signaling. In addition, hMSC reduced microglia population and inhibited the pro-inflammatory phenotype of the remaining microglia. CONCLUSIONS Using a co-culture model, we demonstrated the paracrine effect of hMSC on RGC survival after injury concomitant with a reduction of microglial population. Paracrine signaling of hMSC also changed microglia phenotype and the expression of antiinflammatory factors in the retina. Our results are consistent with a detrimental effect of microglia on RGC survival and regeneration after injury.
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Affiliation(s)
- Leandro C Teixeira-Pinheiro
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, Brazil.
| | - Maria F Toledo
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, Brazil
| | | | - Rosalia Mendez-Otero
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, Brazil
| | - Louise A Mesentier-Louro
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil; Department of Ophthalmology, Stanford University, Palo Alto, USA
| | - Marcelo F Santiago
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa, Brazil
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von Saucken VE, Jay TR, Landreth GE. The effect of amyloid on microglia-neuron interactions before plaque onset occurs independently of TREM2 in a mouse model of Alzheimer's disease. Neurobiol Dis 2020; 145:105072. [PMID: 32890775 PMCID: PMC7808254 DOI: 10.1016/j.nbd.2020.105072] [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: 06/19/2020] [Revised: 08/13/2020] [Accepted: 08/30/2020] [Indexed: 12/23/2022] Open
Abstract
Genetic studies identified mutations in several immune-related genes that confer increased risk for developing Alzheimer’s disease (AD), suggesting a key role for microglia in AD pathology. Microglia are recruited to and actively modulate the local toxicity of amyloid plaques in models of AD through these cells’ transcriptional and functional reprogramming to a disease-associated phenotype. However, it remains unknown whether microglia actively respond to amyloid accumulation before plaque deposition in AD. We compared microglial interactions with neurons that exhibit amyloid accumulation to those that do not in 1-month-old 5XFAD mice to determine which aspects of microglial morphology and function are altered by early 6E10+ amyloid accumulation. We provide evidence of preferential microglial process engagement of amyloid laden neurons. Microglia, on exposure to amyloid, also increase their internalization of neurites even before plaque onset. Unexpectedly, we found that triggering receptor expressed on myeloid cells 2 (TREM2), which is critical for microglial responses to amyloid plaque pathology later in disease, is not required for enhanced microglial interactions with neurons or neurite internalization early in disease. However, TREM2 was still required for early morphological changes exhibited by microglia. These data demonstrate that microglia sense and respond to amyloid accumulation before plaques form using a distinct mechanism from the TREM2-dependent pathway required later in disease.
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Affiliation(s)
- Victoria E von Saucken
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Taylor R Jay
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gary E Landreth
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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Hughes AN, Appel B. Microglia phagocytose myelin sheaths to modify developmental myelination. Nat Neurosci 2020; 23:1055-1066. [PMID: 32632287 PMCID: PMC7483351 DOI: 10.1038/s41593-020-0654-2] [Citation(s) in RCA: 172] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 05/13/2020] [Indexed: 12/15/2022]
Abstract
During development, oligodendrocytes contact and wrap neuronal axons with myelin. Similarly to neurons and synapses, excess myelin sheaths are produced and selectively eliminated, but how elimination occurs is unknown. Microglia, the resident immune cells of the central nervous system, engulf surplus neurons and synapses. To determine whether microglia also prune myelin sheaths, we used zebrafish to visualize and manipulate interactions between microglia, oligodendrocytes, and neurons during development. We found that microglia closely associate with oligodendrocytes and specifically phagocytose myelin sheaths. By using a combination of optical, genetic, chemogenetic, and behavioral approaches, we reveal that neuronal activity bidirectionally balances microglial association with neuronal cell bodies and myelin phagocytosis in the optic tectum. Furthermore, multiple strategies to deplete microglia resulted in oligodendrocytes maintaining excessive and ectopic myelin. Our work reveals a neuronal activity-regulated role for microglia in modifying developmental myelin targeting by oligodendrocytes.
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Affiliation(s)
| | - Bruce Appel
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Aurora, CO, USA.
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224
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Pinto MV, Fernandes A. Microglial Phagocytosis-Rational but Challenging Therapeutic Target in Multiple Sclerosis. Int J Mol Sci 2020; 21:ijms21175960. [PMID: 32825077 PMCID: PMC7504120 DOI: 10.3390/ijms21175960] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022] Open
Abstract
Multiple sclerosis (MS) is the most common autoimmune and demyelinating disease of the central nervous system (CNS), characterized, in the majority of cases, by initial relapses that later evolve into progressive neurodegeneration, severely impacting patients’ motor and cognitive functions. Despite the availability of immunomodulatory therapies effective to reduce relapse rate and slow disease progression, they all failed to restore CNS myelin that is necessary for MS full recovery. Microglia are the primary inflammatory cells present in MS lesions, therefore strongly contributing to demyelination and lesion extension. Thus, many microglial-based therapeutic strategies have been focused on the suppression of microglial pro-inflammatory phenotype and neurodegenerative state to reduce disease severity. On the other hand, the contribution of myelin phagocytosis advocating the neuroprotective role of microglia in MS has been less explored. Indeed, despite the presence of functional oligodendrocyte precursor cells (OPCs), within lesioned areas, MS plaques fail to remyelinate as a result of the over-accumulation of myelin-toxic debris that must be cleared away by microglia. Dysregulation of this process has been associated with the impaired neuronal recovery and deficient remyelination. In line with this, here we provide a comprehensive review of microglial myelin phagocytosis and its involvement in MS development and repair. Alongside, we discuss the potential of phagocytic-mediated therapeutic approaches and encourage their modulation as a novel and rational approach to ameliorate MS-associated pathology.
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Affiliation(s)
- Maria V. Pinto
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal;
| | - Adelaide Fernandes
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal;
- Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal
- Correspondence: ; Tel.: +351-217946400
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225
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Willis EF, MacDonald KPA, Nguyen QH, Garrido AL, Gillespie ER, Harley SBR, Bartlett PF, Schroder WA, Yates AG, Anthony DC, Rose-John S, Ruitenberg MJ, Vukovic J. Repopulating Microglia Promote Brain Repair in an IL-6-Dependent Manner. Cell 2020; 180:833-846.e16. [PMID: 32142677 DOI: 10.1016/j.cell.2020.02.013] [Citation(s) in RCA: 264] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 11/21/2019] [Accepted: 02/05/2020] [Indexed: 12/20/2022]
Abstract
Cognitive dysfunction and reactive microglia are hallmarks of traumatic brain injury (TBI), yet whether these cells contribute to cognitive deficits and secondary inflammatory pathology remains poorly understood. Here, we show that removal of microglia from the mouse brain has little effect on the outcome of TBI, but inducing the turnover of these cells through either pharmacologic or genetic approaches can yield a neuroprotective microglial phenotype that profoundly aids recovery. The beneficial effects of these repopulating microglia are critically dependent on interleukin-6 (IL-6) trans-signaling via the soluble IL-6 receptor (IL-6R) and robustly support adult neurogenesis, specifically by augmenting the survival of newborn neurons that directly support cognitive function. We conclude that microglia in the mammalian brain can be manipulated to adopt a neuroprotective and pro-regenerative phenotype that can aid repair and alleviate the cognitive deficits arising from brain injury.
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Affiliation(s)
- Emily F Willis
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Kelli P A MacDonald
- Department of Immunology, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Quan H Nguyen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Adahir Labrador Garrido
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Ellen R Gillespie
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Samuel B R Harley
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Perry F Bartlett
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Wayne A Schroder
- Department of Immunology, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; School of Environment and Science, Griffith University, QLD, Brisbane, Australia
| | - Abi G Yates
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Daniel C Anthony
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Stefan Rose-John
- Biochemisches Institut, Christian Albrechts Universität Kiel, Kiel, Germany
| | - Marc J Ruitenberg
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Jana Vukovic
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
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226
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Jurga AM, Paleczna M, Kuter KZ. Overview of General and Discriminating Markers of Differential Microglia Phenotypes. Front Cell Neurosci 2020; 14:198. [PMID: 32848611 PMCID: PMC7424058 DOI: 10.3389/fncel.2020.00198] [Citation(s) in RCA: 486] [Impact Index Per Article: 121.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/05/2020] [Indexed: 12/12/2022] Open
Abstract
Inflammatory processes and microglia activation accompany most of the pathophysiological diseases in the central nervous system. It is proven that glial pathology precedes and even drives the development of multiple neurodegenerative conditions. A growing number of studies point out the importance of microglia in brain development as well as in physiological functioning. These resident brain immune cells are divergent from the peripherally infiltrated macrophages, but their precise in situ discrimination is surprisingly difficult. Microglial heterogeneity in the brain is especially visible in their morphology and cell density in particular brain structures but also in the expression of cellular markers. This often determines their role in physiology or pathology of brain functioning. The species differences between rodent and human markers add complexity to the whole picture. Furthermore, due to activation, microglia show a broad spectrum of phenotypes ranging from the pro-inflammatory, potentially cytotoxic M1 to the anti-inflammatory, scavenging, and regenerative M2. A precise distinction of specific phenotypes is nowadays essential to study microglial functions and tissue state in such a quickly changing environment. Due to the overwhelming amount of data on multiple sets of markers that is available for such studies, the choice of appropriate markers is a scientific challenge. This review gathers, classifies, and describes known and recently discovered protein markers expressed by microglial cells in their different phenotypes. The presented microglia markers include qualitative and semi-quantitative, general and specific, surface and intracellular proteins, as well as secreted molecules. The information provided here creates a comprehensive and practical guide through the current knowledge and will facilitate the choosing of proper, more specific markers for detailed studies on microglia and neuroinflammatory mechanisms in various physiological as well as pathological conditions. Both basic research and clinical medicine need clearly described and validated molecular markers of microglia phenotype, which are essential in diagnostics, treatment, and prevention of diseases engaging glia activation.
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Affiliation(s)
- Agnieszka M Jurga
- Maj Institute of Pharmacology, Department of Neuropsychopharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Martyna Paleczna
- Maj Institute of Pharmacology, Department of Neuropsychopharmacology, Polish Academy of Sciences, Krakow, Poland
| | - Katarzyna Z Kuter
- Maj Institute of Pharmacology, Department of Neuropsychopharmacology, Polish Academy of Sciences, Krakow, Poland
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227
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Anti-inflammatory effects of higenamine (Hig) on LPS-activated mouse microglia (BV2) through NF-κB and Nrf2/HO-1 signaling pathways. Int Immunopharmacol 2020; 85:106629. [DOI: 10.1016/j.intimp.2020.106629] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/09/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022]
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228
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Yanguas‐Casás N, Crespo‐Castrillo A, Arevalo M, Garcia‐Segura LM. Aging and sex: Impact on microglia phagocytosis. Aging Cell 2020; 19:e13182. [PMID: 32725944 PMCID: PMC7431836 DOI: 10.1111/acel.13182] [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: 04/07/2020] [Revised: 05/23/2020] [Accepted: 06/06/2020] [Indexed: 01/08/2023] Open
Abstract
Microglia dysfunction and activation are important hallmarks of the aging brain and are concomitant with age-related neurodegeneration and cognitive decline. Age-associated changes in microglia migration and phagocytic capacity result in maladaptive responses, chronic neuroinflammation, and worsened outcomes in neurodegenerative disorders. Given the sex bias in the incidence, prevalence, and therapy response of most neurological disorders, we have here examined whether the phagocytic activity of aged microglia is different in males and females. With this aim, the phagocytosis activity of male and female cells was compared in an in vitro aged microglia model and in microglia isolated from adult (5-month-old) or aged (18-month-old) mice. In both models, the phagocytosis of neural debris increased with aging in male and female cells and was higher in aged female microglia than in aged male cells. However, female aged microglia lost its ability to adapt its phagocytic activity to inflammatory conditions. These findings suggest that microglia phagocytosis of neural debris may represent a previously unexplored neuroprotective characteristic of aged microglia that may contribute to the generation of sex differences in the manifestation of neurodegenerative diseases.
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Affiliation(s)
- Natalia Yanguas‐Casás
- Consejo Superior de Investigaciones Científicas (CSIC) Instituto Cajal Madrid Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES) Instituto de Salud Carlos III Madrid Spain
| | | | - Maria‐Angeles Arevalo
- Consejo Superior de Investigaciones Científicas (CSIC) Instituto Cajal Madrid Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES) Instituto de Salud Carlos III Madrid Spain
| | - Luis Miguel Garcia‐Segura
- Consejo Superior de Investigaciones Científicas (CSIC) Instituto Cajal Madrid Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES) Instituto de Salud Carlos III Madrid Spain
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229
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Picca A, Calvani R, Coelho-Junior HJ, Landi F, Bernabei R, Marzetti E. Mitochondrial Dysfunction, Oxidative Stress, and Neuroinflammation: Intertwined Roads to Neurodegeneration. Antioxidants (Basel) 2020; 9:antiox9080647. [PMID: 32707949 PMCID: PMC7466131 DOI: 10.3390/antiox9080647] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress develops as a response to injury and reflects a breach in the cell’s antioxidant capacity. Therefore, the fine-tuning of reactive oxygen species (ROS) generation is crucial for preserving cell’s homeostasis. Mitochondria are a major source and an immediate target of ROS. Under different stimuli, including oxidative stress and impaired quality control, mitochondrial constituents (e.g., mitochondrial DNA, mtDNA) are displaced toward intra- or extracellular compartments. However, the mechanisms responsible for mtDNA unloading remain largely unclear. While shuttling freely within the cell, mtDNA can be delivered into the extracellular compartment via either extrusion of entire nucleoids or the generation and release of extracellular vesicles. Once discarded, mtDNA may act as a damage-associated molecular pattern (DAMP) and trigger an innate immune inflammatory response by binding to danger-signal receptors. Neuroinflammation is associated with a large array of neurological disorders for which mitochondrial DAMPs could represent a common thread supporting disease progression. The exploration of non-canonical pathways involved in mitochondrial quality control and neurodegeneration may unveil novel targets for the development of therapeutic agents. Here, we discuss these processes in the setting of two common neurodegenerative diseases (Alzheimer’s and Parkinson’s disease) and Down syndrome, the most frequent progeroid syndrome.
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Affiliation(s)
- Anna Picca
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Rome, Italy; (A.P.); (F.L.); (E.M.)
| | - Riccardo Calvani
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Rome, Italy; (A.P.); (F.L.); (E.M.)
- Correspondence: (R.C.); (R.B.); Tel.: +39-06-3015-5559 (R.C. & R.B.); Fax: +39-06-3051-911 (R.C. & R.B.)
| | | | - Francesco Landi
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Rome, Italy; (A.P.); (F.L.); (E.M.)
- Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
| | - Roberto Bernabei
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Rome, Italy; (A.P.); (F.L.); (E.M.)
- Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
- Correspondence: (R.C.); (R.B.); Tel.: +39-06-3015-5559 (R.C. & R.B.); Fax: +39-06-3051-911 (R.C. & R.B.)
| | - Emanuele Marzetti
- Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Rome, Italy; (A.P.); (F.L.); (E.M.)
- Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
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Guedes VA, Devoto C, Leete J, Sass D, Acott JD, Mithani S, Gill JM. Extracellular Vesicle Proteins and MicroRNAs as Biomarkers for Traumatic Brain Injury. Front Neurol 2020; 11:663. [PMID: 32765398 PMCID: PMC7378746 DOI: 10.3389/fneur.2020.00663] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022] Open
Abstract
Traumatic brain injury (TBI) is a heterogeneous condition, associated with diverse etiologies, clinical presentations and degrees of severity, and may result in chronic neurobehavioral sequelae. The field of TBI biomarkers is rapidly evolving to address the many facets of TBI pathology and improve its clinical management. Recent years have witnessed a marked increase in the number of publications and interest in the role of extracellular vesicles (EVs), which include exosomes, cell signaling, immune responses, and as biomarkers in a number of pathologies. Exosomes have a well-defined lipid bilayer with surface markers that reflect the cell of origin and an aqueous core that contains a variety of biological material including proteins (e.g., cytokines and growth factors) and nucleic acids (e.g., microRNAs). The presence of proteins associated with neurodegenerative changes such as amyloid-β, α-synuclein and phosphorylated tau in exosomes suggests a role in the initiation and propagation of neurological diseases. However, mechanisms of cell communication involving exosomes in the brain and their role in TBI pathology are poorly understood. Exosomes are promising TBI biomarkers as they can cross the blood-brain barrier and can be isolated from peripheral fluids, including serum, saliva, sweat, and urine. Exosomal content is protected from enzymatic degradation by exosome membranes and reflects the internal environment of their cell of origin, offering insights into tissue-specific pathological processes. Challenges in the clinical use of exosomal cargo as biomarkers include difficulty in isolating pure exosomes, variable yields of the isolation processes, quantification of vesicles, and lack of specificity of exosomal markers. Moreover, there is no consensus regarding nomenclature and characteristics of EV subtypes. In this review, we discuss current technical limitations and challenges of using exosomes and other EVs as blood-based biomarkers, highlighting their potential as diagnostic and prognostic tools in TBI.
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Affiliation(s)
- Vivian A Guedes
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Christina Devoto
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Jacqueline Leete
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Delia Sass
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Jedidiah D Acott
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Sara Mithani
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Jessica M Gill
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
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Zhou W, Zhou Y, Wang M, Qian C, Wang C, Tang J, Cai Z, Dai W, Zhu X. Pharmacological inhibition of CXCR2 alleviates neuropathic pain by inactivating microglia in a rat L5 spinal nerve ligation model. Am J Transl Res 2020; 12:3803-3812. [PMID: 32774736 PMCID: PMC7407742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
Peripheral nerve injury (PNI)-induced neuropathic pain is a prevalent and severe clinical problem. It has been shown that microglia-mediated neuroinflammation plays a crucial role in neuropathic pain. The present study investigated the abnormal expression of C-X-C motif chemokine receptor type 2 (CXCR2) in a rat L5 spinal nerve ligation (SNL) model and evaluated the role of SB225002, a specific antagonist of CXCR2, in repressing neuroinflammation and neuropathic pain. It was found that CXCR2 expression was significantly upregulated in the dorsal horn of L5-SNL rats compared with sham control. Moreover, CXCR2 expression was increased in spinal microglia of rats after L5-SNL. Based on these results, the present study further examined whether pharmacological inhibition of CXCR2 suppressed microglial activation and neuropathic pain. It was demonstrated that SB225002 treatment inhibited L5-SNL-induced microglia proliferation and activation. Furthermore, SB225002 also significantly suppressed the L5-SNL-induced pro-inflammatory response, as indicated by decreased production of tumor necrosis factor-α, interleukin (IL)-1β and IL-6 in spinal cord tissues. The results indicated that SB225002 also significantly inhibited microglial cell viability and lipopolysaccharide-induced production of pro-inflammatory cytokines in cultured microglia. Functionally, SB225002 treatment effectively repressed mechanical and cold hypersensitivity after peripheral nerve injury. Collectively, the present results suggested that pharmacological inhibition of CXCR2 by SB225002 suppressed L5-SNL-induced neuroinflammation and neuropathic pain, thus offering a potential therapeutic strategy for neuropathic pain treatment.
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Affiliation(s)
- Wang Zhou
- Department of Anesthesiology, Affiliated Hospital of Nantong UniversityNantong 226001, Jiangsu, P. R. China
- School of Medicine, Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Yuan Zhou
- Department of Anesthesiology, Affiliated Hospital of Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Miqun Wang
- Department of Anesthesiology, Qingdao Women and Children’s HospitalQingdao 266034, P. R. China
| | - Cheng Qian
- Department of Traditional Chinese Medicine, Affiliated Hospital of Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Cancan Wang
- School of Medicine, Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Jiani Tang
- School of Medicine, Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Zhenyuan Cai
- School of Medicine, Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Wei Dai
- School of Medicine, Nantong UniversityNantong 226001, Jiangsu, P. R. China
| | - Xiang Zhu
- Department of Anesthesiology, Affiliated Hospital of Nantong UniversityNantong 226001, Jiangsu, P. R. China
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232
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Fu H, Zhao Y, Hu D, Wang S, Yu T, Zhang L. Depletion of microglia exacerbates injury and impairs function recovery after spinal cord injury in mice. Cell Death Dis 2020; 11:528. [PMID: 32661227 PMCID: PMC7359318 DOI: 10.1038/s41419-020-2733-4] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 11/24/2022]
Abstract
The role of microglia in spinal cord injury (SCI) remains ambiguous, partially due to the paucity of efficient methods to discriminate these resident microglia with blood-derived monocytes/macrophages. Here, we used pharmacological treatments to specifically eliminate microglia and subsequently to investigate the response of microglia after SCI in mice. We showed that treatment with colony stimulating factor 1 receptor (CSF1R) inhibitor PLX3397 eliminated ~90% microglia and did not affect other cell types in mouse spinal cord. PLX3397 treatment also induced a strong decrease in microglial proliferation induced by SCI. Depletion of microglia after SCI disrupted glial scar formation, enhanced immune cell infiltrates, reduced neuronal survival, delayed astrocyte repopulation, exacerbated axonal dieback, and impaired locomotor recovery. Therefore, our findings suggest microglia may play a protective role after SCI in mice.
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Affiliation(s)
- Haitao Fu
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China.,Department of Orthopaedics, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yanpeng Zhao
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Die Hu
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Song Wang
- School of Medicine, Nankai University, Tianjin, China
| | - Tengbo Yu
- Department of Orthopaedics, The Affiliated Hospital of Qingdao University, Qingdao, China.
| | - Licheng Zhang
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China.
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233
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Han KM, Kang RJ, Jeon H, Lee HJ, Lee JS, Park H, Gak Jeon S, Suk K, Seo J, Hoe HS. Regorafenib Regulates AD Pathology, Neuroinflammation, and Dendritic Spinogenesis in Cells and a Mouse Model of AD. Cells 2020; 9:cells9071655. [PMID: 32660121 PMCID: PMC7408082 DOI: 10.3390/cells9071655] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/27/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
The oral multi-target kinase inhibitor regorafenib, which targets the oncogenic receptor tyrosine kinase (RTK), is an effective therapeutic for patients with advanced gastrointestinal stromal tumors or metastatic colorectal cancer. However, whether regorafenib treatment has beneficial effects on neuroinflammation and Alzheimer’s disease (AD) pathology has not been carefully addressed. Here, we report the regulatory function of regorafenib in neuroinflammatory responses and AD-related pathology in vitro and in vivo. Regorafenib affected AKT signaling to attenuate lipopolysaccharide (LPS)-mediated expression of proinflammatory cytokines in BV2 microglial cells and primary cultured microglia and astrocytes. In addition, regorafenib suppressed LPS-induced neuroinflammatory responses in LPS-injected wild-type mice. In 5x FAD mice (a mouse model of AD), regorafenib ameliorated AD pathology, as evidenced by increased dendritic spine density and decreased Aβ plaque levels, by modulating APP processing and APP processing-associated proteins. Furthermore, regorafenib-injected 5x FAD mice displayed significantly reduced tau phosphorylation at T212 and S214 (AT100) due to the downregulation of glycogen synthase kinase-3 beta (GSK3β) activity. Taken together, our results indicate that regorafenib has beneficial effects on neuroinflammation, AD pathology, and dendritic spine formation in vitro and in vivo.
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Affiliation(s)
- Kyung-Min Han
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu 42988, Korea
| | - Ri Jin Kang
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
- Department of Pharmacology, Brain Science & Engineering Institute, School of Medicine, Kyungpook National University, Daegu 41944, Korea;
| | - Hyongjun Jeon
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
| | - Hyun-ju Lee
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
| | - Ji-Soo Lee
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
| | - HyunHee Park
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
| | - Seong Gak Jeon
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science & Engineering Institute, School of Medicine, Kyungpook National University, Daegu 41944, Korea;
| | - Jinsoo Seo
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu 42988, Korea
- Correspondence: (J.S.); (H.-S.H.); Tel.: +82-53-420-4835 (J.S.); +82-53-980-8310 (H.-S.H.)
| | - Hyang-Sook Hoe
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu 41068, Korea; (K.-M.H.); (R.J.K.); (H.J.); (H.-j.L.); (J.-S.L.); (H.P.); (S.G.J.)
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu 42988, Korea
- Correspondence: (J.S.); (H.-S.H.); Tel.: +82-53-420-4835 (J.S.); +82-53-980-8310 (H.-S.H.)
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234
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Var SR, Byrd-Jacobs CA. Role of Macrophages and Microglia in Zebrafish Regeneration. Int J Mol Sci 2020; 21:E4768. [PMID: 32635596 PMCID: PMC7369716 DOI: 10.3390/ijms21134768] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022] Open
Abstract
Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.
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235
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Tyrosine Kinase Receptors Axl and MerTK Mediate the Beneficial Effect of Electroacupuncture in a Cuprizone-Induced Demyelinating Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:3205176. [PMID: 32714402 PMCID: PMC7355344 DOI: 10.1155/2020/3205176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/16/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022]
Abstract
Electroacupuncture has been shown to promote remyelination in a demyelinating model of multiple sclerosis (MS) through enhanced microglial clearance of degraded myelin debris. However, the mechanisms involved in this process are yet to be clearly elucidated. It has been revealed that TAM receptor tyrosine kinases (Tyro3, Axl, and MerTK) play pivotal roles in regulating multiple features of microglia, including the phagocytic function and myelin clearance. Therefore, the aim of this study is to further confirm whether electroacupuncture improves functional recovery in this model and to characterise the involvement of the TAM receptor during this process. In addition to naive control mice, a cuprizone-induced demyelinating model was established, and long-term electroacupuncture treatment was administrated. To evaluate the efficiency of functional recovery following demyelination, we performed beam-walking test and rotarod performance test; to objectify the degree of remyelination, we performed transmission electron microscopy and protein quantification of mature oligodendrocyte markers. Oil Red O staining was used to evaluate the deposit of myelin debris. We confirmed that, in cuprizone-treated mice, electroacupuncture significantly ameliorates motor-coordinative dysfunction and counteracts demyelinating processes, with less deposit of myelin debris accumulating in the corpus callosum. Surprisingly, mRNA expression of TAM receptors was significantly upregulated after electroacupuncture treatment, and we further confirmed an increased protein expression of Axl and MerTK after electroacupuncture treatment, indicating their involvement during electroacupuncture treatment. Finally, LDC1267, a selective TAM kinase inhibitor, abolished the therapeutic effect of electroacupuncture on motor-coordinative dysfunction. Overall, our data demonstrate that electroacupuncture could mitigate the progression of demyelination by enhancing the TAM receptor expression to facilitate the clearance of myelin debris. Our results also suggest that electroacupuncture may be a potential curative treatment for MS patients.
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236
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Apamin Suppresses LPS-Induced Neuroinflammatory Responses by Regulating SK Channels and TLR4-Mediated Signaling Pathways. Int J Mol Sci 2020; 21:ijms21124319. [PMID: 32560481 PMCID: PMC7352249 DOI: 10.3390/ijms21124319] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/11/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroinflammation plays a vital role in neurodegenerative conditions. Microglia are a key component of the neuroinflammatory response. There is a growing interest in developing drugs to target microglia and thereby control neuroinflammatory processes. Apamin (APM) is a specifically selective antagonist of small conductance calcium-activated potassium (SK) channels. However, its effect on neuroinflammation is largely unknown. We examine the effects of APM on lipopolysaccharide (LPS)-stimulated BV2 and rat primary microglial cells. Regarding the molecular mechanism by which APM significantly inhibits proinflammatory cytokine production and microglial cell activation, we found that APM does so by reducing the expression of phosphorylated CaMKII and toll-like receptor (TLR4). In particular, APM potently suppressed the translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/signal transducer and activator of transcription (STAT)3 and phosphorylated mitogen-activated protein kinases (MAPK)-extracellular signal-regulated kinase (ERK). In addition, the correlation of NF-κB/STAT3 and MAPK-ERK in the neuroinflammatory response was verified through inhibitors. The literature and our findings suggest that APM is a promising candidate for an anti-neuroinflammatory agent and can potentially be used for the prevention and treatment of various neurological disorders.
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237
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Zhang C, Frye MD, Sun W, Sharma A, Manohar S, Salvi R, Hu BH. New insights on repeated acoustic injury: Augmentation of cochlear susceptibility and inflammatory reaction resultant of prior acoustic injury. Hear Res 2020; 393:107996. [PMID: 32534268 DOI: 10.1016/j.heares.2020.107996] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 04/29/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022]
Abstract
In industrial and military settings, individuals who suffer from one episode of acoustic trauma are likely to sustain another episode of acoustic stress, creating an opportunity for a potential interaction between the two stress conditions. We previously demonstrated that acoustic overstimulation perturbs the cochlear immune environment. However, how the cochlear immune system responds to repeated acoustic overstimulation is unknown. Here, we used a mouse model to investigate the cochlear immune response to repeated stress. We reveal that exposure to an intense noise at 120 dB SPL for 1 h activates the cochlear immune response in a time-dependent fashion with substantial expansion and activation of the macrophage population in the cochlea at 2-days post-exposure. At 20-days post-exposure, the number and pro-inflammatory phenotypes of cochlear macrophages have significantly subsided, but have yet to return to homeostatic levels. Monocytes with anti-inflammatory phenotypes are recruited into the cochlea. With the presence of this residual immune activation, a second exposure to the same noise provokes an exaggerated inflammatory response as evidenced by exacerbated maturation of macrophages. Furthermore, the second noise causes greater sensory cell pathogenesis. Unlike the first noise-induced damage that occurs mainly between 0 and 2 days post-exposure, the second noise-induced damage occurs more frequently between 2 and 20 days post-exposure, the period when secondary damage takes place. These observations suggest that repeated acoustic overstimulation exacerbates cochlear inflammation and secondary sensory cell pathogenesis. Together, our results suggest that the cochlear immune system plays an important role in modulating cochlear responses to repeated acoustic stress.
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Affiliation(s)
- Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Mitchell D Frye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Wei Sun
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Ashu Sharma
- Department of Oral Biology, University at Buffalo, School of Dental Medicine, University of Buffalo, The State University of New York, Buffalo, NY, USA, 14214.
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
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238
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Tahirbegi B, Magness AJ, Piersimoni ME, Knöpfel T, Willison KR, Klug DR, Ying L. A Novel Aβ 40 Assembly at Physiological Concentration. Sci Rep 2020; 10:9477. [PMID: 32528074 PMCID: PMC7289798 DOI: 10.1038/s41598-020-66373-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/15/2020] [Indexed: 01/27/2023] Open
Abstract
Aggregates of amyloid-β (Aβ) are characteristic of Alzheimer's disease, but there is no consensus as to either the nature of the toxic molecular complex or the mechanism by which toxic aggregates are produced. We report on a novel feature of amyloid-lipid interactions where discontinuities in the lipid continuum can serve as catalytic centers for a previously unseen microscale aggregation phenomenon. We show that specific lipid membrane conditions rapidly produce long contours of lipid-bound peptide, even at sub-physiological concentrations of Aβ. Using single molecule fluorescence, time-lapse TIRF microscopy and AFM imaging we characterize this phenomenon and identify some exceptional properties of the aggregation pathway which make it a likely contributor to early oligomer and fibril formation, and thus a potential critical mechanism in the etiology of AD. We infer that these amyloidogenic events occur only at areas of high membrane curvature, which suggests a range of possible mechanisms by which accumulated physiological changes may lead to their inception. The speed of the formation is in hours to days, even at 1 nM peptide concentrations. Lipid features of this type may act like an assembly line for monomeric and small oligomeric subunits of Aβ to increase their aggregation states. We conclude that under lipid environmental conditions, where catalytic centers of the observed type are common, key pathological features of AD may arise on a very short timescale under physiological concentration.
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Affiliation(s)
- Bogachan Tahirbegi
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Alastair J Magness
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Thomas Knöpfel
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Keith R Willison
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - David R Klug
- Department of Chemistry, Imperial College London, London, United Kingdom.
| | - Liming Ying
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.
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239
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Genetically Modified Mesenchymal Stem Cells: The Next Generation of Stem Cell-Based Therapy for TBI. Int J Mol Sci 2020; 21:ijms21114051. [PMID: 32516998 PMCID: PMC7312789 DOI: 10.3390/ijms21114051] [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: 05/19/2020] [Revised: 05/29/2020] [Accepted: 06/04/2020] [Indexed: 02/07/2023] Open
Abstract
Mesenchymal stem cells (MSCs) are emerging as an attractive approach for restorative medicine in central nervous system (CNS) diseases and injuries, such as traumatic brain injury (TBI), due to their relatively easy derivation and therapeutic effect following transplantation. However, the long-term survival of the grafted cells and therapeutic efficacy need improvement. Here, we review the recent application of MSCs in TBI treatment in preclinical models. We discuss the genetic modification approaches designed to enhance the therapeutic potency of MSCs for TBI treatment by improving their survival after transplantation, enhancing their homing abilities and overexpressing neuroprotective and neuroregenerative factors. We highlight the latest preclinical studies that have used genetically modified MSCs for TBI treatment. The recent developments in MSCs’ biology and potential TBI therapeutic targets may sufficiently improve the genetic modification strategies for MSCs, potentially bringing effective MSC-based therapies for TBI treatment in humans.
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240
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Hall CM, Moeendarbary E, Sheridan GK. Mechanobiology of the brain in ageing and Alzheimer's disease. Eur J Neurosci 2020; 53:3851-3878. [DOI: 10.1111/ejn.14766] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 02/07/2023]
Affiliation(s)
- Chloe M. Hall
- Department of Mechanical Engineering University College London London UK
- School of Pharmacy and Biomolecular Sciences University of Brighton Brighton UK
| | - Emad Moeendarbary
- Department of Mechanical Engineering University College London London UK
- Department of Biological Engineering Massachusetts Institute of Technology Cambridge MA USA
| | - Graham K. Sheridan
- School of Life Sciences Queens Medical Centre University of Nottingham Nottingham UK
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241
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Vinueza-Veloz MF, Martín-Román C, Robalino-Valdivieso MP, White T, Kushner SA, De Zeeuw CI. Genetic risk for Alzheimer disease in children: Evidence from early-life IQ and brain white-matter microstructure. GENES BRAIN AND BEHAVIOR 2020; 19:e12656. [PMID: 32383552 PMCID: PMC7507145 DOI: 10.1111/gbb.12656] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/01/2020] [Accepted: 04/17/2020] [Indexed: 01/21/2023]
Abstract
It remains unclear whether the genetic risk for late‐onset Alzheimer disease (AD) is linked to premorbid individual differences in general cognitive ability and brain structure. The objective of the present study was to determine whether the genetic risk of late‐onset AD is related to premorbid individual differences in intelligence quotient (IQ) and characteristics of the cerebral white‐matter in children. The study sample included children of the Generation R Study from Rotterdam, The Netherlands. IQ was measured using a well‐validated Dutch nonverbal IQ test (n = 1908) at ages 5 to 9 years. White‐matter microstructure was assessed by measuring fractional anisotropy (FA) of white‐matter tracts using diffusion tensor imaging (DTI) (n = 919) at ages 9 to 12 years. Genetic risk was quantified using three biologically defined genetic risk scores (GRSs) hypothesized to be related to the pathophysiology of late‐onset AD: immune response, cholesterol/lipid metabolism and endocytosis. Higher genetic risk for late‐onset AD that included genes associated with immune responsivity had a negative influence on cognition and cerebral white‐matter microstructure. For each unit increase in the immune response GRS, IQ decreased by 0.259 SD (95% CI [−0.500, −0.017]). For each unit increase in the immune response GRS, global FA decreased by 0.373 SD (95% CI [−0.721, −0.026]). Neither cholesterol/lipid metabolism nor endocytosis GRSs were associated with IQ or cerebral white‐matter microstructure. Our findings suggest that elevated genetic risk for late‐onset AD may in part be manifest during childhood neurodevelopment through alterations in immune responsivity.
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Affiliation(s)
- María Fernanda Vinueza-Veloz
- School of Medicine, Escuela Superior Politécnica de Chimborazo, Riobamba, Ecuador.,Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Carlos Martín-Román
- Leiden Institute for Advanced Computer Science, Leiden University, Leiden, The Netherlands
| | | | - Tonya White
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, Rotterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus MC, Rotterdam, The Netherlands.,Department of Psychiatry, Columbia University, New York City, United States of America, United States of America
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.,Royal Netherlands Academy of Arts and Sciences, The Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
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242
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Collins L, Brunjes P. Experimental Demyelination of the Lateral Olfactory Tract and Anterior Commissure. Neuroscience 2020; 434:93-101. [PMID: 32224229 DOI: 10.1016/j.neuroscience.2020.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 11/27/2022]
Abstract
Demyelination significantly affects brain function. Several experimental methods, each inducing varying levels of myelin and neuronal damage, have been developed to understand the process of myelin loss and to find new therapies to promote remyelination. The present work investigates the effect of one such method, lysolecithin administration, on the white matter tracts in the olfactory system. The olfactory forebrain contains two distinct tracts with differing developmental histories, axonal composition, and function: the lateral olfactory tract (LOT), which carries ipsilateral olfactory information from the olfactory bulb to olfactory cortex, and the anterior commissure (AC), which interconnects olfactory regions across hemispheres. The effects of lysolecithin injections were assessed in two ways: (1) the expression of myelin basic protein, a component of compacted myelin sheaths, was quantified using immunohistochemistry and (2) electron microscopy was used to obtain measurements of myelin thickness of individual axons as well as qualitative descriptions of the extent of damage to myelin and surrounding tissue. Data were collected at 7, 14, 21, and 30 days post-injection (dpi). While both the LOT and AC exhibited significant demyelination at 7 dpi and had returned to control levels by 30 dpi, the process differed between the two tracts. Remyelination occurred more rapidly in the LOT: substantial recovery was observed in the LOT by 14 dpi, but not in the AC until 21 dpi. The findings indicate that (a) the LOT and AC are indeed suitable tracts for studying lysolecithin-induced de- and remyelination and (b) experimental demyelination proceeds differently between the two tracts.
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Affiliation(s)
- Lindsay Collins
- University of Virginia, Department of Psychology, United States; University of Oregon, Institute of Neuroscience, United States.
| | - Peter Brunjes
- University of Virginia, Department of Psychology, United States
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243
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Zhao J, Wang B, Wu X, Yang Z, Huang T, Guo X, Guo D, Liu Z, Song J. TGFβ1 alleviates axonal injury by regulating microglia/macrophages alternative activation in traumatic brain injury. Brain Res Bull 2020; 161:21-32. [PMID: 32389801 DOI: 10.1016/j.brainresbull.2020.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/21/2020] [Accepted: 04/15/2020] [Indexed: 12/26/2022]
Abstract
Traumatic brain injury (TBI) causes substantial mortality and long-term disability worldwide. TGFβ1 is a unique molecular and functional signature in microglia, but the role of TGFβ1 in TBI is not clear. The purpose of this study was to investigate the role of TGFβ1 in TBI. The weight dropping device was used to establish TBI model of rats. Hematoxylin eosin staining and Bielschowsky silver staining were used to assess tissue loss. Beam walking and muscle strength tests were used to assess neurological deficits. Immunohistochemical staining was used to assess axonal injures. Western blotting was used to detect expression of related proteins. RT-PCR was used to detect expression of cytokines. Immunofluorescence staining was used to assess the microglia/macrophages activation. We observed obvious axonal injury and microglia/macrophages activation in the peri-lesion cortex. The expression of inflammatory cytokines was markedly high after TBI. The expression of TGFβ1 and TGFβRI were significantly reduced after TBI. TGFβ1 promoted the functional recovery and alleviated axonal injury 1 day after TBI. TGFβ1 promoted microglia/macrophages polarizing to alternative activation and alleviated neuroinflammation. These effects of TGFβ1 could be inhibited by LY2109761, the inhibitor of TGFRI/II. These results suggested that TGFβ1 played a protective role in axonal injury and could be a potential therapeutic target in early stages following TBI.
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Affiliation(s)
- Junjie Zhao
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Bo Wang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Xiang Wu
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Zhongbo Yang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Tingqin Huang
- Department of Neurosurgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Xiaoye Guo
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Dan Guo
- Department of Science and Technology, Xi'an Medical University, Xi'an, Shaanxi 710021, China
| | - Zunwei Liu
- Institute of Organ Transplantation, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China; Department of Renal Transplantation, Nephropathy Hospital, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Jinning Song
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China.
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Yoon Y, Kim HS, Jeon I, Noh JE, Park HJ, Lee S, Park IH, Stevanato L, Hicks C, Corteling R, Barker RA, Sinden JD, Song J. Implantation of the clinical-grade human neural stem cell line, CTX0E03, rescues the behavioral and pathological deficits in the quinolinic acid-lesioned rodent model of Huntington's disease. Stem Cells 2020; 38:936-947. [PMID: 32374064 PMCID: PMC7496241 DOI: 10.1002/stem.3191] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 03/23/2020] [Accepted: 04/01/2020] [Indexed: 12/27/2022]
Abstract
Huntington's disease (HD) is a devastating, autosomal-dominant neurodegenerative disease, for which there are currently no disease-modifying therapies. Clinical trials to replace the damaged striatal medium spiny neurons (MSNs) have been attempted in the past two decades but have met with only limited success. In this study, we investigated whether a clonal, conditionally immortalized neural stem cell line (CTX0E03), which has already shown safety and signals of efficacy in chronic ischemic stroke patients, could rescue deficits seen in an animal model of HD. After CTX0E03 transplantation into the quinolinic acid-lesioned rat model of HD, behavioral changes were measured using the rotarod, stepping, and staircase tests. In vivo differentiation and neuronal connections of the transplanted CTX0E03 cells were evaluated with immunohistochemical staining and retrograde tracing with Fluoro-Gold. We found that transplantation of CTX0E03 gave rise to a significant behavioral improvement compared with the sham- or fibroblast-transplanted group. Transplanted CTX0E03 formed MSNs (DARPP-32) and GABAergic neurons (GABA, GAD65/67) with BDNF expression in the striatum, while cortically transplanted cells formed Tbr1-positive neurons. Using a retrograde label, we also found stable engraftment and connection of the transplanted cells with host brain tissues. CTX0E03 transplantation also reduced glial scar formation and inflammation, as well as increasing endogenous neurogenesis and angiogenesis. Overall, our results demonstrate that CTX0E03, a clinical-grade neural stem cell line, is effective for preclinical test in HD, and, therefore, will be useful for clinical development in the treatment of HD patients.
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Affiliation(s)
- Yongwoo Yoon
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Hyun Sook Kim
- Department of Neurology, CHA Bundang Medical Center, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Iksoo Jeon
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Jeong-Eun Noh
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Hyun Jung Park
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Suji Lee
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut, USA
| | | | | | | | - Roger A Barker
- John van Geest Cambridge Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | | | - Jihwan Song
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea.,iPS Bio, Inc., Seongnam-si, Gyeonggi-do, Republic of Korea
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245
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The Role of Osteopontin in Amyotrophic Lateral Sclerosis: A Systematic Review. ARCHIVES OF NEUROSCIENCE 2020. [DOI: 10.5812/ans.94205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Context: Osteopontin (OPN) is a matrix phosphoprotein expressed by a variety of tissues and cells, including the immune system and the nervous system. Previous studies have shown that OPN may have a role in neurodegenerative diseases, including multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease. Objectives: The present study aimed to systematically review studies investigating the role of OPN in amyotrophic lateral sclerosis (ALS) patients or the disease animal model. Evidence Acquisition: We searched the Cochrane Library, PubMed, Web of Science, and Scopus to find relevant articles published up to January 20, 2019. Both human and animal model studies of ALS were considered. Results: A total of nine articles (four human studies and five animal model studies) were included. Two of the human studies reported that the CSF levels of OPN were higher among ALS patients compared to controls. The other two human studies found that OPN levels in cortical neurons did not differ significantly between ALS cases and the non-neurological control group. One of the studies found that the expression level of OPN in astrocytes was similar between ALS patients and the control group, but the level of microglial OPN significantly increased in ALS cases. Four of the animal model studies reported that the expression of OPN mRNA in spinal cord microglia significantly increased during the disease progression. The remaining animal model study found that OPN was selectively expressed by fast fatigue-resistant and slow motor neurons (MNs), which are resistant to ALS, and that the OPN expression was low among fast-fatigable MNs. Conclusions: Prompt microglial activation is a hallmark pathology of ALS, and OPN is among the most widely expressed proteins by these activated glial cells. Therefore, OPN might have a role in ALS pathogenesis. The existing evidence is not sufficient to justify whether OPN has a neurotoxic or neuroprotective role in ALS. We encourage researchers to investigate the role of OPN in ALS pathogenesis more extensively.
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246
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Microglial and Astrocytic Function in Physiological and Pathological Conditions: Estrogenic Modulation. Int J Mol Sci 2020; 21:ijms21093219. [PMID: 32370112 PMCID: PMC7247358 DOI: 10.3390/ijms21093219] [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: 03/30/2020] [Revised: 04/24/2020] [Accepted: 04/30/2020] [Indexed: 12/20/2022] Open
Abstract
There are sexual differences in the onset, prevalence, and outcome of numerous neurological diseases. Thus, in Alzheimer’s disease, multiple sclerosis, and major depression disorder, the incidence in women is higher than in men. In contrast, men are more likely to present other pathologies, such as amyotrophic lateral sclerosis, Parkinson’s disease, and autism spectrum. Although the neurological contribution to these diseases has classically always been studied, the truth is that neurons are not the only cells to be affected, and there are other cells, such as glial cells, that are also involved and could be key to understanding the development of these pathologies. Sexual differences exist not only in pathology but also in physiological processes, which shows how cells are differentially regulated in males and females. One of the reasons these sexual differences may occur could be due to the different action of sex hormones. Many studies have shown an increase in aromatase levels in the brain, which could indicate the main role of estrogens in modulating proinflammatory processes. This review will highlight data about sex differences in glial physiology and how estrogenic compounds, such as estradiol and tibolone, could be used as treatment in neurological diseases due to their anti-inflammatory effects and the ability to modulate glial cell functions.
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247
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Dwyer Z, Rudyk C, Situt D, Beauchamp S, Abdali J, Dinesh A, Legancher N, Sun H, Schlossmacher M, Hayley S. Microglia depletion prior to lipopolysaccharide and paraquat treatment differentially modulates behavioral and neuronal outcomes in wild type and G2019S LRRK2 knock-in mice. Brain Behav Immun Health 2020; 5:100079. [PMID: 34589856 PMCID: PMC8474533 DOI: 10.1016/j.bbih.2020.100079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Substantial data have implicated microglial-driven neuroinflammation in Parkinson's disease (PD) and environmental toxicants have been long expected as triggers of such inflammatory processes. Of course, these environmental insults act in the context of genetic vulnerability factors and in this regard, leucine rich repeat kinase 2 (LRRK2), may play a prominent role. METHODS We used a double hit, lipopolysaccharide (LPS; endotoxin) followed by paraquat (pesticide toxicant) model of PD in mice with the most common LRRK2 mutation G2019S, knockin mice and wild type littermates. In order to assess the contribution of microglia, we depleted these cells (through 14 days of the CSF-1 antagonist, PLX-3397) prior to LPS and paraquat exposure. RESULTS We found that the G2019S mice displayed the greatest signs of behavioral pathology, but that the PLX-3397 induced microglial depletion at the time of LPS exposure diminished toxicity and weight loss and blunted the reduction in home-cage activity with subsequent paraquat exposure. However, neither the PLX-3397 pre-treatment nor the G2019S mutation affected the LPS + paraquat induced loss of substantia nigra pars compacta (SNc) dopamine neurons or elevation of circulating immune (IL-6) or stress (corticosterone) factors. Intriguingly, microglial morphological ratings were basally enhanced in G2019S mice and the PLX-3397 pre-treatment reversed this effect. Moreover, PLX-3397 pre-treatment selectively elevated soluble a-synuclein and SIRT3 levels, while reducing SNc caspase-1 and 3, along with CX3CR1. Hence, the re-populated "new" microglia following cessation of PLX-3397 clearly had an altered phenotype or were immature at the time of sacrifice (i.e. after 11 days). CONCLUSIONS Collectively, these findings suggest that G2019S knock-in and PLX-3397 microglial depletion at the time of LPS exposure affects behavioral, but not neurodegenerative responses to subsequent environmental toxin exposure.
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Affiliation(s)
- Zach Dwyer
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Chris Rudyk
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Divya Situt
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Sheryl Beauchamp
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Jawaria Abdali
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Anu Dinesh
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | | | - Hongyu Sun
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | | | - Shawn Hayley
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - CLINT (Canadian LRRK2 in inflammation team)
- Department of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
- University of Ottawa, Canada
- Ottawa Hospital Research Institute, Canada
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Propofol Attenuates Hypoxia-Induced Inflammation in BV2 Microglia by Inhibiting Oxidative Stress and NF- κB/Hif-1 α Signaling. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8978704. [PMID: 32420378 PMCID: PMC7204316 DOI: 10.1155/2020/8978704] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/11/2020] [Accepted: 04/17/2020] [Indexed: 01/29/2023]
Abstract
Hypoxia-induced neuroinflammation typically causes neurological damage and can occur during stroke, neonatal hypoxic-ischemic encephalopathy, and other diseases. Propofol is widely used as an intravenous anesthetic. Studies have shown that propofol has antineuroinflammatory effect. However, the underlying mechanism remains to be fully elucidated. Thus, we aimed to investigate the beneficial effects of propofol against hypoxia-induced neuroinflammation and elucidated its potential cellular and biochemical mechanisms of action. In this study, we chose cobalt chloride (CoCl2) to establish a hypoxic model. We found that propofol decreased hypoxia-induced proinflammatory cytokines (TNFα, IL-1β, and IL-6) in BV2 microglia, significantly suppressed the excessive production of reactive oxygen species, and increased the total antioxidant capacity and superoxide dismutase activity. Furthermore, propofol attenuated the hypoxia-induced decrease in mitochondrial membrane potential andy 2 strongly inhibited protein expression of nuclear factor-kappa B (NF-κB) subunit p65 and hypoxia inducible factor-1α (Hif-1α) in hypoxic BV2 cells. To investigate the role of NF-κB p65, specific small interfering RNA (siRNA) against NF-κB p65 were transfected into BV2 cells, followed by exposure to hypoxia for 24 h. Hypoxia-induced Hif-1α production was downregulated after NF-κB p65 silencing. Further, propofol suppressed Hif-1α expression by inhibiting the upregulation of NF-κB p65 after exposure to hypoxia in BV2 microglia. In summary, propofol attenuates hypoxia-induced neuroinflammation, at least in part by inhibiting oxidative stress and NF-κB/Hif-1α signaling.
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249
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Yuan Y, Wu C, Ling EA. Heterogeneity of Microglia Phenotypes: Developmental, Functional and Some Therapeutic Considerations. Curr Pharm Des 2020; 25:2375-2393. [PMID: 31584369 DOI: 10.2174/1381612825666190722114248] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/12/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Microglia play a pivotal role in maintaining homeostasis in complex brain environment. They first exist as amoeboid microglial cells (AMCs) in the developing brain, but with brain maturation, they transform into ramified microglial cells (RMCs). In pathological conditions, microglia are activated and have been classified into M1 and M2 phenotypes. The roles of AMCs, RMCs and M1/M2 microglia phenotypes especially in pathological conditions have been the focus of many recent studies. METHODS Here, we review the early development of the AMCs and RMCs and discuss their specific functions with reference to their anatomic locations, immunochemical coding etc. M1 and M2 microglia phenotypes in different neuropathological conditions are also reviewed. RESULTS Activated microglia are engaged in phagocytosis, production of proinflammatory mediators, trophic factors and synaptogenesis etc. Prolonged microglia activation, however, can cause damage to neurons and oligodendrocytes. The M1 and M2 phenotypes featured prominently in pathological conditions are discussed in depth. Experimental evidence suggests that microglia phenotype is being modulated by multiple factors including external and internal stimuli, local demands, epigenetic regulation, and herbal compounds. CONCLUSION Prevailing views converge that M2 polarization is neuroprotective. Thus, proper therapeutic designs including the use of anti-inflammatory drugs, herbal agents may be beneficial in suppression of microglial activation, especially M1 phenotype, for amelioration of neuroinflammation in different neuropathological conditions. Finally, recent development of radioligands targeting 18 kDa translocator protein (TSPO) in activated microglia may hold great promises clinically for early detection of brain lesion with the positron emission tomography.
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Affiliation(s)
- Yun Yuan
- Department of Anatomy and Histology/Embryology, Kunming Medical University, 1168 West Chunrong Road, Kunming, China
| | - Chunyun Wu
- Department of Anatomy and Histology/Embryology, Kunming Medical University, 1168 West Chunrong Road, Kunming, China
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, 4 Medical Drive, MD10, National University of Singapore, 117594, Singapore
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250
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Traiffort E, Kassoussi A, Zahaf A, Laouarem Y. Astrocytes and Microglia as Major Players of Myelin Production in Normal and Pathological Conditions. Front Cell Neurosci 2020; 14:79. [PMID: 32317939 PMCID: PMC7155218 DOI: 10.3389/fncel.2020.00079] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/19/2020] [Indexed: 12/13/2022] Open
Abstract
Myelination is an essential process that consists of the ensheathment of axons by myelin. In the central nervous system (CNS), myelin is synthesized by oligodendrocytes. The proliferation, migration, and differentiation of oligodendrocyte precursor cells constitute a prerequisite before mature oligodendrocytes extend their processes around the axons and progressively generate a multilamellar lipidic sheath. Although myelination is predominately driven by oligodendrocytes, the other glial cells including astrocytes and microglia, also contribute to this process. The present review is an update of the most recent emerging mechanisms involving astrocyte and microglia in myelin production. The contribution of these cells will be first described during developmental myelination that occurs in the early postnatal period and is critical for the proper development of cognition and behavior. Then, we will report the novel findings regarding the beneficial or deleterious effects of astroglia and microglia, which respectively promote or impair the endogenous capacity of oligodendrocyte progenitor cells (OPCs) to induce spontaneous remyelination after myelin loss. Acute delineation of astrocyte and microglia activities and cross-talk should uncover the way towards novel therapeutic perspectives aimed at recovering proper myelination during development or at breaking down the barriers impeding the regeneration of the damaged myelin that occurs in CNS demyelinating diseases.
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Affiliation(s)
| | | | - Amina Zahaf
- U1195 Inserm, University Paris-Saclay, Kremlin-Bicêtre, France
| | - Yousra Laouarem
- U1195 Inserm, University Paris-Saclay, Kremlin-Bicêtre, France
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