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Spielbauer J, Glotfelty E, Sarlus H, Harris RA, Heijtz RD, Karlsson TE. Bacterial peptidoglycan signalling in microglia: Activation by MDP via the NF-κB/MAPK pathway. Brain Behav Immun 2024:S0889-1591(24)00467-7. [PMID: 38971207 DOI: 10.1016/j.bbi.2024.06.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 06/26/2024] [Accepted: 06/28/2024] [Indexed: 07/08/2024] Open
Abstract
Bacterial peptidoglycan (PGN) fragments are commonly studied in the context of bacterial infections. However, PGN fragments recently gained recognition as signalling molecules from the commensal gut microbiota in the healthy host. Here we focus on the minimal bioactive PGN motif muramyl dipeptide (MDP), found in both Gram-positive and Gram-negative commensal bacteria, which signals through the Nod2 receptor. MDP from the gut microbiota translocates to the brain and is associated with changes in neurodevelopment and behaviour, yet there is limited knowledge about the underlying mechanisms. In this study we demonstrate that physiologically relevant doses of MDP induce rapid changes in microglial gene expression and lead to cytokine and chemokine secretion. In immortalised microglial (IMG) cells, C-C Motif Chemokine Ligand 5 (CCL5/RANTES) expression is acutely sensitive to the lowest physiologically prevalent dose (0.1 µg/ml) of MDP. As CCL5 plays an important role in memory formation and synaptic plasticity, microglial CCL5 might be the missing link in elucidating MDP-induced alterations in synaptic gene expression. We observed that a higher physiological dose of MDP elevates the expression of cytokines TNF-α and IL-1β, indicating a transition toward a pro-inflammatory phenotype in IMG cells, which was validated in primary microglial cultures. Furthermore, MDP induces the translocation of NF-κB subunit p65 into the nucleus, which is blocked by MAPK p38 inhibitor SB202190, suggesting that an interplay of both the NF-κB and MAPK pathways is responsible for the MDP-specific microglial phenotype. These findings underscore the significance of different MDP levels in shaping microglial function in the CNS and indicate MDP as a potential mediator for early inflammatory processes in the brain. It also positions microglia as an important target in the gut microbiota-brain-axis pathway through PGN signalling.
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Affiliation(s)
- Julia Spielbauer
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Elliot Glotfelty
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Heela Sarlus
- Department of Clinical Neuroscience, Karolinska Institutet, Centre for Molecular Medicine, Karolinska Hospital at Solna, 171 77 Stockholm, Sweden
| | - Robert A Harris
- Department of Clinical Neuroscience, Karolinska Institutet, Centre for Molecular Medicine, Karolinska Hospital at Solna, 171 77 Stockholm, Sweden
| | | | - Tobias E Karlsson
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
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Robertson KV, Rodriguez AS, Cartailler JP, Shrestha S, Schroeder KR, Valenti AM, Harrison FE, Hasty AH. Knockdown of microglial iron import gene, DMT1, worsens cognitive function and alters microglial transcriptional landscape in a sex-specific manner in the APP/PS1 model of Alzheimer's disease. RESEARCH SQUARE 2024:rs.3.rs-4559940. [PMID: 38978579 PMCID: PMC11230470 DOI: 10.21203/rs.3.rs-4559940/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Background Microglial cell iron load and inflammatory activation are significant hallmarks of late-stage Alzheimer's disease (AD). In vitro, microglia preferentially upregulate the iron importer, divalent metal transporter 1 (DMT1, gene name Slc11a2) in response to inflammatory stimuli, and excess iron can augment cellular inflammation, suggesting a feed-forward loop between iron import mechanisms and inflammatory signaling. However, it is not understood whether microglial iron import mechanisms directly contribute to inflammatory signaling and chronic disease in vivo. These studies determined the effects of microglial-specific knockdown of Slc11a2 on AD-related cognitive decline and microglial transcriptional phenotype. Methods In vitro experiments and RT-qPCR were used to assess a role for DMT1 in amyloid-β-associated inflammation. To determine the effects of microglial Slc11a2 knockdown on AD-related phenotypes in vivo, triple-transgenic Cx3cr1 Cre - ERT2 ;Slc11a2 flfl;APP/PS1 + or - mice were generated and administered corn oil or tamoxifen to induce knockdown at 5-6 months of age. Both sexes underwent behavioral analyses to assess cognition and memory (12-15 months of age). Hippocampal CD11b + microglia were magnetically isolated from female mice (15-17 months) and bulk RNA-sequencing analysis was conducted. Results DMT1 inhibition in vitro robustly decreased Aβ-induced inflammatory gene expression and cellular iron levels in conditions of excess iron. In vivo, Slc11a2 KD APP/PS1 female, but not male, mice displayed a significant worsening of memory function in Morris water maze and a fear conditioning assay, along with significant hyperactivity compared to control WT and APP/PS1 mice. Hippocampal microglia from Slc11a2 KD APP/PS1 females displayed significant increases in Enpp2, Ttr, and the iron-export gene, Slc40a1, compared to control APP/PS1 cells. Slc11a2 KD cells from APP/PS1 females also exhibited decreased expression of markers associated with disease-associated microglia (DAMs), such as Apoe, Ctsb, Csf1, and Hif1α. Conclusions This work suggests a sex-specific role for microglial iron import gene Slc11a2 in propagating behavioral and cognitive phenotypes in the APP/PS1 model of AD. These data also highlight an association between loss of a DAM-like phenotype in microglia and cognitive deficits in Slc11a2 KD APP/PS1 female mice. Overall, this work illuminates an iron-related pathway in microglia that may serve a protective role during disease and offers insight into mechanisms behind disease-related sex differences.
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Charoensaensuk V, Huang BR, Huang ST, Lin C, Xie SY, Chen CW, Chen YC, Cheng HT, Liu YS, Lai SW, Shen CK, Lin HJ, Yang LY, Lu DY. LPS priming-induced immune tolerance mitigates LPS-stimulated microglial activation and social avoidance behaviors in mice. J Pharmacol Sci 2024; 154:225-235. [PMID: 38485340 DOI: 10.1016/j.jphs.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 03/19/2024] Open
Abstract
In this study, we investigated the regulatory mechanisms underlying the effects of LPS tolerance on the inflammatory homeostasis of immune cells. LPS priming-induced immune tolerance downregulated cyclooxygenase-2, and lowered the production of prostaglandin-E2 in microglial cells. In addition, LPS tolerance downregulated the expression of suppressor of cytokine signaling 3, and inducible nitric oxide synthase/nitric oxide; suppressed the LPS-mediated induction of tumor necrosis factor-α, interleukin (IL)-6, and IL-1; and reduced reactive oxygen species production in microglial cells. LPS stimulation increased the levels of the adaptive response-related proteins heme oxygenase-1 and superoxide dismutase 2, and the levels of heme oxygenase-1 (HO-1) enhanced after LPS priming. Systemic administration of low-dose LPS (0.5 mg/kg) to mice for 4 consecutive days attenuated high-dose LPS (5 mg/kg)-induced inflammatory response, microglial activation, and proinflammatory cytokine expression. Moreover, repeated exposure to low-dose LPS suppressed the recruitment of peripheral monocytes or macrophages to brain regions and downregulated the expression of proinflammatory cytokines. Notably, LPS-induced social avoidance behaviors in mice were mitigated by immune tolerance. In conclusion, immune tolerance may reduce proinflammatory cytokine expression and reactive oxygen species production. Our findings provide insights into the effects of endotoxin tolerance on innate immune cells and social behaviors.
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Affiliation(s)
- Vichuda Charoensaensuk
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Bor-Ren Huang
- Department of Neurosurgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Sian-Ting Huang
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Chingju Lin
- Department of Physiology, School of Medicine, China Medical University, Taichung, 404328, Taiwan
| | - Sheng-Yun Xie
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Chao-Wei Chen
- Institute of New Drug Development, China Medical University, Taichung, Taiwan
| | - Yen-Chang Chen
- Institute of New Drug Development, China Medical University, Taichung, Taiwan
| | - Han-Tsung Cheng
- Department of Surgery, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Shu Liu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Sheng-Wei Lai
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Ching-Kai Shen
- Graduate Institute of Biomedical Science, China Medical University, Taichung, Taiwan
| | - Hui-Jung Lin
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, China Medical University, Taichung, 404328, Taiwan; Laboratory for Neural Repair, China Medical University Hospital, Taichung, 404327, Taiwan; Biomedical Technology R&D Center, China Medical University Hospital, Taichung, 404327, Taiwan.
| | - Dah-Yuu Lu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan; Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan.
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Li H, Watkins LR, Wang X. Microglia in neuroimmunopharmacology and drug addiction. Mol Psychiatry 2024:10.1038/s41380-024-02443-6. [PMID: 38302560 DOI: 10.1038/s41380-024-02443-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
Drug addiction is a chronic and debilitating disease that is considered a global health problem. Various cell types in the brain are involved in the progression of drug addiction. Recently, the xenobiotic hypothesis has been proposed, which frames substances of abuse as exogenous molecules that are responded to by the immune system as foreign "invaders", thus triggering protective inflammatory responses. An emerging body of literature reveals that microglia, the primary resident immune cells in the brain, play an important role in the progression of addiction. Repeated cycles of drug administration cause a progressive, persistent induction of neuroinflammation by releasing microglial proinflammatory cytokines and their metabolic products. This contributes to drug addiction via modulation of neuronal function. In this review, we focus on the role of microglia in the etiology of drug addiction. Then, we discuss the dynamic states of microglia and the correlative and causal evidence linking microglia to drug addiction. Finally, possible mechanisms of how microglia sense drug-related stimuli and modulate the addiction state and how microglia-targeted anti-inflammation therapies affect addiction are reviewed. Understanding the role of microglia in drug addiction may help develop new treatment strategies to fight this devastating societal challenge.
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Affiliation(s)
- Hongyuan Li
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China
| | - Linda R Watkins
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
- Beijing National Laboratory for Molecular Sciences, Beijing, 100190, China.
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Xu L, Min H, Saha A, Gunaratne A, Schwartzman J, Parrott R, Kurtzberg J, Filiano AJ. Mesenchymal stromal cells suppress microglial activation and tumor necrosis factor production. Cytotherapy 2024; 26:185-193. [PMID: 38054911 DOI: 10.1016/j.jcyt.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 11/03/2023] [Accepted: 11/16/2023] [Indexed: 12/07/2023]
Abstract
BACKGROUND AIMS White matter diseases are commonly associated with microglial activation and neuroinflammation. Mesenchymal stromal cells (MSCs) have immunomodulatory properties and thus have the potential to be developed as cell therapy for white matter disease. MSCs interact with resident macrophages to alter the trajectory of inflammation; however, the impact MSCs have on central nervous system macrophages and the effect this has on the progression of white matter disease are unclear. METHODS In this study, we utilized numerous assays of varying complexity to model different aspects of white matter disease. These assays ranged from an in vivo spinal cord acute demyelination model to a simple microglial cell line activation assay. Our goal was to investigate the influence of human umbilical cord tissue MSCs on the activation of microglia. RESULTS MSCs reduced the production of tumor necrosis factor (TNF) by microglia and decreased demyelinated lesions in the spinal cord after acute focal injury. To determine if MSCs could directly suppress the activation of microglia and to develop an efficient potency assay, we utilized isolated primary microglia from mouse brains and the Immortalized MicroGlial Cell Line (IMG). MSCs suppressed the activation of microglia and the release of TNF after stimulation with lipopolysaccharide, a toll-like receptor agonist. CONCLUSIONS In this study, we demonstrated that MSCs altered the immune response after acute injury in the spinal cord. In numerous assays, MSCs suppressed activation of microglia and release of the pro-inflammatory cytokine TNF. Of these assays, IMG could be standardized and used as an effective potency assay to determine the efficacy of MSCs for treating white matter disease or other neuroinflammatory conditions associated with microglial activation.
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Affiliation(s)
- Li Xu
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA
| | - Hyunjung Min
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA
| | - Arjun Saha
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA
| | - Aruni Gunaratne
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA; Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | | | - Roberta Parrott
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA
| | - Joanne Kurtzberg
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA; Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | - Anthony J Filiano
- Marcus Center for Cellular Cures, Duke University, Durham, North Carolina, USA; Department of Neurosurgery, Duke University, Durham, North Carolina, USA; Department of Integrative Immunobiology, Duke University, Durham, North Carolina, USA; Department of Pathology, Duke University, Durham, North Carolina, USA.
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6
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Yadav N, Purow BW. Understanding current experimental models of glioblastoma-brain microenvironment interactions. J Neurooncol 2024; 166:213-229. [PMID: 38180686 PMCID: PMC11056965 DOI: 10.1007/s11060-023-04536-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
Glioblastoma (GBM) is a common and devastating primary brain tumor, with median survival of 16-18 months after diagnosis in the setting of substantial resistance to standard-of-care and inevitable tumor recurrence. Recent work has implicated the brain microenvironment as being critical for GBM proliferation, invasion, and resistance to treatment. GBM does not operate in isolation, with neurons, astrocytes, and multiple immune populations being implicated in GBM tumor progression and invasiveness. The goal of this review article is to provide an overview of the available in vitro, ex vivo, and in vivo experimental models for assessing GBM-brain interactions, as well as discuss each model's relative strengths and limitations. Current in vitro models discussed will include 2D and 3D co-culture platforms with various cells of the brain microenvironment, as well as spheroids, whole organoids, and models of fluid dynamics, such as interstitial flow. An overview of in vitro and ex vivo organotypic GBM brain slices is also provided. Finally, we conclude with a discussion of the various in vivo rodent models of GBM, including xenografts, syngeneic grafts, and genetically-engineered models of GBM.
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Affiliation(s)
- Niket Yadav
- Department of Neurology, University of Virginia Comprehensive Cancer Center, University of Virginia Health System, Charlottesville, VA, 22903, USA
- Medical Scientist Training Program, School of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Benjamin W Purow
- Department of Neurology, University of Virginia Comprehensive Cancer Center, University of Virginia Health System, Charlottesville, VA, 22903, USA.
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Nomura M, Murad NF, Madhavan SS, Eap B, Garcia TY, Aguirre CG, Verdin E, Ellerby L, Furman D, Newman JC. A ketogenic diet reduces age-induced chronic neuroinflammation in mice Running title: ketogenic diet and brain inflammaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569598. [PMID: 38106160 PMCID: PMC10723274 DOI: 10.1101/2023.12.01.569598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Beta-hydroxybutyrate (BHB) is a ketone body synthesized during fasting or strenuous exercise. Our previous study demonstrated that a cyclic ketogenic diet (KD), which induces BHB levels similar to fasting every other week, reduces midlife mortality and improves memory in aging mice. BHB actively regulates gene expression and inflammatory activation through non-energetic signaling pathways. Neither of these activities has been well-characterized in the brain and they may represent mechanisms by which BHB affects brain function during aging. First, we analyzed hepatic gene expression in an aging KD-treated mouse cohort using bulk RNA-seq. In addition to the downregulation of TOR pathway activity, cyclic KD reduces inflammatory gene expression in the liver. We observed via flow cytometry that KD also modulates age-related systemic T cell functions. Next, we investigated whether BHB affects brain cells transcriptionally in vitro. Gene expression analysis in primary human brain cells (microglia, astrocytes, neurons) using RNA-seq shows that BHB causes a mild level of inflammation in all three cell types. However, BHB inhibits the more pronounced LPS-induced inflammatory gene activation in microglia. Furthermore, we confirmed that BHB similarly reduces LPS-induced inflammation in primary mouse microglia and bone marrow-derived macrophages (BMDMs). BHB is recognized as an inhibitor of histone deacetylase (HDAC), an inhibitor of NLRP3 inflammasome, and an agonist of the GPCR Hcar2. Nevertheless, in microglia, BHB's anti-inflammatory effects are independent of these known mechanisms. Finally, we examined the brain gene expression of 12-month-old male mice fed with one-week and one-year cyclic KD. While a one-week KD increases inflammatory signaling, a one-year cyclic KD reduces neuroinflammation induced by aging. In summary, our findings demonstrate that BHB mitigates the microglial response to inflammatory stimuli, like LPS, possibly leading to decreased chronic inflammation in the brain after long-term KD treatment in aging mice.
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Affiliation(s)
| | | | - Sidharth S Madhavan
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Brenda Eap
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | | | - Carlos Galicia Aguirre
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Eric Verdin
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Lisa Ellerby
- Buck Institute for Research on Aging, Novato, CA, USA
| | - David Furman
- Buck Institute for Research on Aging, Novato, CA, USA
| | - John C Newman
- Buck Institute for Research on Aging, Novato, CA, USA
- Division of Geriatrics, University of California, San Francisco, San Francisco, CA, USA
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Zhang S, Yi S, Wang L, Li S, Wang H, Song L, Ou J, Zhang M, Wang R, Wang M, Zheng Y, Yang K, Liu T, Ho MS. Cyclin-G-associated kinase GAK/dAux regulates autophagy initiation via ULK1/Atg1 in glia. Proc Natl Acad Sci U S A 2023; 120:e2301002120. [PMID: 37428930 PMCID: PMC10629559 DOI: 10.1073/pnas.2301002120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023] Open
Abstract
Autophagy is a major means for the elimination of protein inclusions in neurons in neurodegenerative diseases such as Parkinson's disease (PD). Yet, the mechanism of autophagy in the other brain cell type, glia, is less well characterized and remains largely unknown. Here, we present evidence that the PD risk factor, Cyclin-G-associated kinase (GAK)/Drosophila homolog Auxilin (dAux), is a component in glial autophagy. The lack of GAK/dAux increases the autophagosome number and size in adult fly glia and mouse microglia, and generally up-regulates levels of components in the initiation and PI3K class III complexes. GAK/dAux interacts with the master initiation regulator UNC-51like autophagy activating kinase 1/Atg1 via its uncoating domain and regulates the trafficking of Atg1 and Atg9 to autophagosomes, hence controlling the onset of glial autophagy. On the other hand, lack of GAK/dAux impairs the autophagic flux and blocks substrate degradation, suggesting that GAK/dAux might play additional roles. Importantly, dAux contributes to PD-like symptoms including dopaminergic neurodegeneration and locomotor function in flies. Our findings identify an autophagy factor in glia; considering the pivotal role of glia under pathological conditions, targeting glial autophagy is potentially a therapeutic strategy for PD.
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Affiliation(s)
- Shiping Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Shuanglong Yi
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Linfang Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Shuhua Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Honglei Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Li Song
- Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai200092, China
| | - Jiayao Ou
- Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai200092, China
| | - Min Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Ruiqi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Mengxiao Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Yuchen Zheng
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Kai Yang
- International Academic Center of Complex Systems, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai519087, China
| | - Tong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai200031, China
| | - Margaret S. Ho
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
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Zhu Y, Huang R, Wang D, Yu L, Liu Y, Huang R, Yin S, He X, Chen B, Liu Z, Cheng L, Zhu R. EVs-mediated delivery of CB2 receptor agonist for Alzheimer's disease therapy. Asian J Pharm Sci 2023; 18:100835. [PMID: 37645682 PMCID: PMC10460952 DOI: 10.1016/j.ajps.2023.100835] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 07/16/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Alzheimer's disease (AD) is a typical neurodegenerative disease that leads to irreversible neuronal degeneration, and effective treatment remains elusive due to the unclear mechanism. We utilized biocompatible mesenchymal stem cell-derived extracellular vesicles as carriers loaded with the CB2 target medicine AM1241 (EVs-AM1241) to protect against neurodegenerative progression and neuronal function in AD model mice. According to the results, EVs-AM1241 were successfully constructed and exhibited better bioavailability and therapeutic effects than bare AM1241. The Morris water maze (MWM) and fear conditioning tests revealed that the learning and memory of EVs-AM1241-treated model mice were significantly improved. In vivo electrophysiological recording of CA1 neurons indicated enhanced response to an auditory conditioned stimulus following fear learning. Immunostaining and Western blot analysis showed that amyloid plaque deposition and amyloid β (Aβ)-induced neuronal apoptosis were significantly suppressed by EVs-AM1241. Moreover, EVs-AM1241 increased the number of neurons and restored the neuronal cytoskeleton, indicating that they enhanced neuronal regeneration. RNA sequencing revealed that EVs-AM1241 facilitated Aβ phagocytosis, promoted neurogenesis and ultimately improved learning and memory through the calcium-Erk signaling pathway. Our study showed that EVs-AM1241 efficiently reversed neurodegenerative pathology and enhanced neurogenesis in model mice, indicating that they are very promising particles for treating AD.
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Affiliation(s)
- Yanjing Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
- Frontier Science Center for Stem Cell Research, Tongji University, Shanghai 200065, China
| | - Ruiqi Huang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Deheng Wang
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Liqun Yu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Yuchen Liu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Runzhi Huang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Shuai Yin
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Xiaolie He
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Bairu Chen
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Zhibo Liu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
| | - Liming Cheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
- Frontier Science Center for Stem Cell Research, Tongji University, Shanghai 200065, China
- Clinical Center For Brain And Spinal Cord Research, Tongji University, Shanghai 200065, China
| | - Rongrong Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Department of Orthopaedics, Tongji Hospital, School of Life Science and Technology, Tongji University, Shanghai 200065, China
- Frontier Science Center for Stem Cell Research, Tongji University, Shanghai 200065, China
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10
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Glotfelty EJ, Tovar-y-Romo LB, Hsueh SC, Tweedie D, Li Y, Harvey BK, Hoffer BJ, Karlsson TE, Olson L, Greig NH. The RhoA-ROCK1/ROCK2 Pathway Exacerbates Inflammatory Signaling in Immortalized and Primary Microglia. Cells 2023; 12:1367. [PMID: 37408199 PMCID: PMC10216802 DOI: 10.3390/cells12101367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 07/07/2023] Open
Abstract
Neuroinflammation is a unifying factor among all acute central nervous system (CNS) injuries and chronic neurodegenerative disorders. Here, we used immortalized microglial (IMG) cells and primary microglia (PMg) to understand the roles of the GTPase Ras homolog gene family member A (RhoA) and its downstream targets Rho-associated coiled-coil-containing protein kinases 1 and 2 (ROCK1 and ROCK2) in neuroinflammation. We used a pan-kinase inhibitor (Y27632) and a ROCK1- and ROCK2-specific inhibitor (RKI1447) to mitigate a lipopolysaccharide (LPS) challenge. In both the IMG cells and PMg, each drug significantly inhibited pro-inflammatory protein production detected in media (TNF-α, IL-6, KC/GRO, and IL-12p70). In the IMG cells, this resulted from the inhibition of NF-κB nuclear translocation and the blocking of neuroinflammatory gene transcription (iNOS, TNF-α, and IL-6). Additionally, we demonstrated the ability of both compounds to block the dephosphorylation and activation of cofilin. In the IMG cells, RhoA activation with Nogo-P4 or narciclasine (Narc) exacerbated the inflammatory response to the LPS challenge. We utilized a siRNA approach to differentiate ROCK1 and ROCK2 activity during the LPS challenges and showed that the blockade of both proteins may mediate the anti-inflammatory effects of Y27632 and RKI1447. Using previously published data, we show that genes in the RhoA/ROCK signaling cascade are highly upregulated in the neurodegenerative microglia (MGnD) from APP/PS-1 transgenic Alzheimer's disease (AD) mice. In addition to illuminating the specific roles of RhoA/ROCK signaling in neuroinflammation, we demonstrate the utility of using IMG cells as a model for primary microglia in cellular studies.
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Affiliation(s)
- Elliot J. Glotfelty
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, USA
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Luis B. Tovar-y-Romo
- Division of Neuroscience, Institute of Cellular Physiology, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Shih-Chang Hsueh
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - David Tweedie
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Yazhou Li
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Brandon K. Harvey
- Molecular Mechanisms of Cellular Stress and Inflammation Unit, Integrative Neuroscience Department, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Barry J. Hoffer
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Tobias E. Karlsson
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Lars Olson
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Nigel H. Greig
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, USA
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11
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Lu BW, Liang YX, Liu JF, Sun ZQ, So KF, Chiu K. Retinal safety and toxicity study of artesunate in vitro and in vivo. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:47-54. [PMID: 37846375 PMCID: PMC10577838 DOI: 10.1016/j.aopr.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/18/2022] [Accepted: 11/25/2022] [Indexed: 10/18/2023]
Abstract
Background Artesunate (ART), a member of the artemisinin family, possesses multi-properties, including anti-inflammation, anti-oxidation, and anti-tumor. ART was recently reported to show anti-neovascularization effect on the cornea, iris, and retina. Compared to the expensive anti-VEGF treatment, this versatile, economical treatment option is attractive in the ophthalmic field. The safety and toxicity profile of ART intravitreal application are in utmost need. Methods In this study, immortalized microglial (IMG) cells were treated with ART to determine the safe concentrations without inducing overt inflammatory reactions. Reverse transcription-polymerase chain reaction analysis was used to detect the cytokine expressions in IMG cells in response to ART stimulation. Various doses of ART were intravitreally injected into the right eyes of C57BL/6 mice. Retinal function was tested by electroretinogram, and retinal ganglion cell (RGC) survival was evaluated by counting Brn3a stained cells in flat-mounted retinas at 7 days after ART injection. Results ART below 5μM was safe for IMG cells in vitro. Both 2.5 and 5 μM ART treatment increased IL-10 gene expression in IMG cells while not changing IL-1β, IL-6, TNF-α, and Arg-1. In the in vivo study, intravitreal injection of ART below 100 μM did not cause deterioration in the retinal function and RGC survival of the mouse eyes, while 1 mM ART treatment significantly attenuated both the scotopic and photopic b-wave amplitudes and impaired RGC survival. In addition, treatment with ART of 25, 50, and 100 μM significantly decreased TNF-α gene expression while ART of 100 μM significantly increased IL-10 in the mouse retina. Conclusions Intravitreal injection of 100 μM ART could downregulate TNF-α while upregulate IL-10 in the mouse retina without causing retinal functional deterioration and RGC loss. ART might be used as anti-inflammatory agent for retinal disorders.
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Affiliation(s)
- Bing-Wen Lu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yu-Xiang Liang
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Department of Psychology, Faculty of Social Sciences, The University of Hong Kong, Hong Kong, China
| | - Jin-Feng Liu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Zhong-Qing Sun
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kwok-Fai So
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Department of Psychology, Faculty of Social Sciences, The University of Hong Kong, Hong Kong, China
- Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Ministry of Education, CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Kin Chiu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Department of Psychology, Faculty of Social Sciences, The University of Hong Kong, Hong Kong, China
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12
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Pearson A, Ortiz C, Eisenbaum M, Arrate C, Browning M, Mullan M, Bachmeier C, Crawford F, Ojo JO. Deletion of PTEN in microglia ameliorates chronic neuroinflammation following repetitive mTBI. Mol Cell Neurosci 2023; 125:103855. [PMID: 37084991 DOI: 10.1016/j.mcn.2023.103855] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/25/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023] Open
Abstract
Traumatic brain injury is a leading cause of morbidity and mortality in adults and children in developed nations. Following the primary injury, microglia, the resident innate immune cells of the CNS, initiate several inflammatory signaling cascades and pathophysiological responses that may persist chronically; chronic neuroinflammation following TBI has been closely linked to the development of neurodegeneration and neurological dysfunction. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that have been shown to regulate several key mechanisms in the inflammatory response to TBI. Increasing evidence has shown that the modulation of the PI3K/AKT signaling pathway has the potential to influence the cellular response to inflammatory stimuli. However, directly targeting PI3K signaling poses several challenges due to its regulatory role in several cell survival pathways. We have previously identified that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN), the major negative regulator of PI3K/AKT signaling, is dysregulated following exposure to repetitive mild traumatic brain injury (r-mTBI). Moreover, this dysregulated PI3K/AKT signaling was correlated with chronic microglial-mediated neuroinflammation. Therefore, we interrogated microglial-specific PTEN as a therapeutic target in TBI by generating a microglial-specific, Tamoxifen inducible conditional PTEN knockout model using a CX3CR1 Cre recombinase mouse line PTENfl/fl/CX3CR1+/CreERT2 (mcg-PTENcKO), and exposed them to our 20-hit r-mTBI paradigm. Animals were treated with tamoxifen at 76 days post-last injury, and the effects of microglia PTEN deletion on immune-inflammatory responses were assessed at 90-days post last injury. We observed that the deletion of microglial PTEN ameliorated the proinflammatory response to repetitive brain trauma, not only reducing chronic microglial activation and proinflammatory cytokine production but also rescuing TBI-induced reactive astrogliosis, demonstrating that these effects extended beyond microglia alone. Additionally, we observed that the pharmacological inhibition of PTEN with BpV(HOpic) ameliorated the LPS-induced activation of microglial NFκB signaling in vitro. Together, these data provide support for the role of PTEN as a regulator of chronic neuroinflammation following repetitive mild TBI.
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Affiliation(s)
- Andrew Pearson
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom.
| | - Camila Ortiz
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Max Eisenbaum
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Clara Arrate
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | | | - Michael Mullan
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Corbin Bachmeier
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Fiona Crawford
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom; James A. Haley Veterans' Hospital, 13000 Bruce B Downs Blvd, Tampa, FL 33612, USA
| | - Joseph O Ojo
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
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13
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Hegdekar N, Sarkar C, Bustos S, Ritzel RM, Hanscom M, Ravishankar P, Philkana D, Wu J, Loane DJ, Lipinski MM. Inhibition of autophagy in microglia and macrophages exacerbates innate immune responses and worsens brain injury outcomes. Autophagy 2023:1-19. [PMID: 36652438 DOI: 10.1080/15548627.2023.2167689] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Excessive and prolonged neuroinflammation following traumatic brain injury (TBI) contributes to long-term tissue damage and poor functional outcomes. However, the mechanisms contributing to exacerbated inflammatory responses after brain injury remain poorly understood. Our previous work showed that macroautophagy/autophagy flux is inhibited in neurons following TBI in mice and contributes to neuronal cell death. In the present study, we demonstrate that autophagy is also inhibited in activated microglia and infiltrating macrophages, and that this potentiates injury-induced neuroinflammatory responses. Macrophage/microglia-specific knockout of the essential autophagy gene Becn1 led to overall increase in neuroinflammation after TBI. In particular, we observed excessive activation of the innate immune responses, including both the type-I interferon and inflammasome pathways. Defects in microglial and macrophage autophagy following injury were associated with decreased phagocytic clearance of danger/damage-associated molecular patterns (DAMP) responsible for activation of the cellular innate immune responses. Our data also demonstrated a role for precision autophagy in targeting and degradation of innate immune pathways components, such as the NLRP3 inflammasome. Finally, inhibition of microglial/macrophage autophagy led to increased neurodegeneration and worse long-term cognitive outcomes after TBI. Conversely, increasing autophagy by treatment with rapamycin decreased inflammation and improved outcomes in wild-type mice after TBI. Overall, our work demonstrates that inhibition of autophagy in microglia and infiltrating macrophages contributes to excessive neuroinflammation following brain injury and in the long term may prevent resolution of inflammation and tissue regeneration.Abbreviations: Becn1/BECN1, beclin 1, autophagy related; CCI, controlled cortical impact; Cybb/CYBB/NOX2: cytochrome b-245, beta polypeptide; DAMP, danger/damage-associated molecular patterns; Il1b/IL1B/Il-1β, interleukin 1 beta; LAP, LC3-associated phagocytosis; Map1lc3b/MAP1LC3/LC3, microtubule-associated protein 1 light chain 3 beta; Mefv/MEFV/TRIM20: Mediterranean fever; Nos2/NOS2/iNOS: nitric oxide synthase 2, inducible; Nlrp3/NLRP3, NLR family, pyrin domain containing 3; Sqstm1/SQSTM1/p62, sequestosome 1; TBI, traumatic brain injury; Tnf/TNF/TNF-α, tumor necrosis factor; Ulk1/ULK1, unc-51 like kinase 1.
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Affiliation(s)
- Nivedita Hegdekar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chinmoy Sarkar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sabrina Bustos
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Rodney M Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Neurology, McGovern Medical School, University of Texas, Houston, Tx, USA
| | - Marie Hanscom
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Prarthana Ravishankar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Deepika Philkana
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.,School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | - Marta M Lipinski
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
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14
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Wu S, Hu L, Lin J, Li K, Ye S, Zhu S, Liu Z. Excretion of Amyloid-β in the Gastrointestinal Tract and Regulation by the Gut Microbiota. J Alzheimers Dis 2022; 90:1153-1162. [DOI: 10.3233/jad-220705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Amyloid-β (Aβ) is important in the etiology of Alzheimer’s disease (AD). Removal of Aβ from the brain is a major strategy for the prevention and treatment of AD. Objective: To clarify whether Aβ 42 can be cleared by intestinal excretion and whether the gut microbiota (GM) can affect the excretory clearance of Aβ 42 in the peripheral blood and intestines. Methods: Male 8-month-old C57BL6 mice were maintained on either normal chow or received broad-spectrum antibiotics in their drinking water for one week. Sterile saline, fluorescein isothiocyanate (FITC), or FITC-Aβ 42 (fluorescein isothiocyanate-labeled amyloid-β 42 peptides) was injected 1 h before FITC, or FITC-Aβ 42 was injected 1 h before sampling. Related changes of Aβ 42 before and after injection were evaluated. Results: FITC-Aβ 42 was injected into mice through the tail vein and could later be detected in feces. Furthermore, the fecal concentrations of FITC-Aβ 42 were higher in mice that had been fed antibiotics to alter their GM than in normal mice. However, the FITC-Aβ 42 concentrations in blood showed the opposite pattern. Conclusion: Aβ 42 can be excreted into the intestinal lumen and is regulated by the GM.
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Affiliation(s)
- Shijing Wu
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Li Hu
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
- Department of Histology and Embryology, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Jiajing Lin
- Department of Psychiatry, Maoming People’s Hospital, MaoMing, Guangdong, China
| | - Kanglan Li
- Department of Pharmacy, Zhanjiang Central Hospital, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Shicai Ye
- Department of Gastroenterology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Shaoping Zhu
- Institute of Laboratory Animal Center, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Zhou Liu
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
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15
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Characterization of IMG Microglial Cell Line as a Valuable In Vitro Tool for NLRP3 Inflammasome Studies. Cell Mol Neurobiol 2022:10.1007/s10571-022-01285-6. [PMID: 36163404 DOI: 10.1007/s10571-022-01285-6] [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: 04/03/2022] [Accepted: 09/14/2022] [Indexed: 11/03/2022]
Abstract
Microglial cells constantly surveil the cerebral microenvironment and become activated following injury and disease to mediate inflammatory responses. The nucleotide-binding oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing 3 (NLRP3) inflammasome, which is abundantly expressed in microglial cells, plays a key role in these responses as well as in the development of many neurological disorders. Microglial cell lines are a valuable tool to study the causes and possible treatments for neurological diseases which are linked to inflammation. Here, we investigated whether the mouse microglial cell line IMG is suitable to study NLRP3 inflammasome by incubating cells with different concentrations of NLRP3 inflammasome priming and activating agents lipopolysaccharide (LPS) and ATP, respectively, and applying short (4 h) or long (24 h) LPS incubation times. After short LPS incubation, the mRNA levels of most pro-inflammatory and NLRP3 inflammasome-associated genes were more upregulated than after long incubation. Moreover, the combination of higher LPS and ATP concentrations with short incubation time resulted in greater levels of active forms of caspase-1 and interleukin-1 beta (IL-1β) proteins than low LPS and ATP concentrations or long incubation time. We also demonstrated that treatment with NLRP3 inflammasome inhibitor glibenclamide suppressed NLRP3 inflammasome activation in IMG cells, as illustrated by the downregulation of gasdermin D N-fragment and mature caspase-1 and IL-1β protein levels. In addition, we conducted similar experiments with primary microglial cells and BV-2 cell line to determine the similarities and differences in their responses. Overall, our results indicate that IMG cell line could be a valuable tool for NLRP3 inflammasome studies. In IMG cells, 4-h incubation with lipopolysaccharide (LPS) induces a stronger upregulation of NLRP3 inflammasome-associated pro-inflammatory genes compared to 24-h incubation. NLRP3 inflammasome is robustly activated only after the addition of 3 mM of ATP following short LPS incubation time.
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16
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Cuní-López C, Stewart R, Quek H, White AR. Recent Advances in Microglia Modelling to Address Translational Outcomes in Neurodegenerative Diseases. Cells 2022; 11:cells11101662. [PMID: 35626698 PMCID: PMC9140031 DOI: 10.3390/cells11101662] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases are deteriorating conditions of the nervous system that are rapidly increasing in the aging population. Increasing evidence suggests that neuroinflammation, largely mediated by microglia, the resident immune cells of the brain, contributes to the onset and progression of neurodegenerative diseases. Hence, microglia are considered a major therapeutic target that could potentially yield effective disease-modifying treatments for neurodegenerative diseases. Despite the interest in studying microglia as drug targets, the availability of cost-effective, flexible, and patient-specific microglia cellular models is limited. Importantly, the current model systems do not accurately recapitulate important pathological features or disease processes, leading to the failure of many therapeutic drugs. Here, we review the key roles of microglia in neurodegenerative diseases and provide an update on the current microglia platforms utilised in neurodegenerative diseases, with a focus on human microglia-like cells derived from peripheral blood mononuclear cells as well as human-induced pluripotent stem cells. The described microglial platforms can serve as tools for investigating disease biomarkers and improving the clinical translatability of the drug development process in neurodegenerative diseases.
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Affiliation(s)
- Carla Cuní-López
- Cell & Molecular Biology Department, Mental Health Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (C.C.-L.); (R.S.)
- Faculty of Medicine, The University of Queensland, Brisbane, QLD 4006, Australia
| | - Romal Stewart
- Cell & Molecular Biology Department, Mental Health Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (C.C.-L.); (R.S.)
- UQ Centre for Clinical Research, The University of Queensland, Royal Brisbane & Women’s Hospital, Brisbane, QLD 4006, Australia
| | - Hazel Quek
- Cell & Molecular Biology Department, Mental Health Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (C.C.-L.); (R.S.)
- Correspondence: (H.Q.); (A.R.W.)
| | - Anthony R. White
- Cell & Molecular Biology Department, Mental Health Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (C.C.-L.); (R.S.)
- Correspondence: (H.Q.); (A.R.W.)
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17
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Iron accumulation induces oxidative stress, while depressing inflammatory polarization in human iPSC-derived microglia. Stem Cell Reports 2022; 17:1351-1365. [PMID: 35523178 PMCID: PMC9213827 DOI: 10.1016/j.stemcr.2022.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 01/08/2023] Open
Abstract
Iron accumulation in microglia has been observed in Alzheimer’s disease and other neurodegenerative disorders and is thought to contribute to disease progression through various mechanisms, including neuroinflammation. To study this interaction, we treated human induced pluripotent stem cell-derived microglia (iPSC-MG) with iron, in combination with inflammatory stimuli such as interferon gamma (IFN-γ) and amyloid β. Both IFN-γ and iron treatment increased labile iron levels, but only iron treatment led to a consistent increase of ferritin levels, reflecting long-term iron storage. Therefore, in iPSC-MG, ferritin appeared to be regulated by iron revels rather than inflammation. Further investigation showed that while IFN-γ induced pro-inflammatory activation, iron treatment dampened both classic pro- and anti-inflammatory activation on a transcriptomic level. Notably, iron-loaded microglia showed strong upregulation of cellular stress response pathways, the NRF2 pathway, and other oxidative stress pathways. Functionally, iPSC-MG exhibited altered phagocytosis and impaired mitochondrial metabolism following iron treatment. Collectively, these data suggest that in MG, in contrast to current hypotheses, iron treatment does not result in pro-inflammatory activation, but rather dampens it and induces oxidative stress. In iPSC-microglia, iron rather than inflammatory activation induces ferritin expression Excessive iron dampens both classic pro- and anti-inflammatory activation Iron uptake leads to upregulation of NRF2 and other oxidative stress pathways Phagocytosis and mitochondrial metabolism are altered following iron uptake
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18
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Zhang P, Guergues J, Alleyne AR, Cirino TJ, Nadeau O, Figueroa AM, Stacy HM, Suzuki T, McLaughlin JP, Stevens SM, Liu B. Novel Histone Modifications in Microglia Derived from a Mouse Model of Chronic Pain. Proteomics 2022; 22:e2100137. [PMID: 35081661 DOI: 10.1002/pmic.202100137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 11/06/2022]
Abstract
As the resident immune cells in the central nervous system, microglia play an important role in the maintenance of its homeostasis. Dysregulation of microglia has been associated with the development and maintenance of chronic pain. However, the relevant molecular pathways remain poorly defined. In this study, we used a mass spectrometry-based proteomic approach to screen potential changes of histone protein modifications in microglia isolated from the brain of control and cisplatin-induced neuropathic pain adult C57BL/6J male mice. We identified several novel microglial histone modifications associated with pain including statistically significantly decreased histone H3.1 lysine 27 mono-methylation (H3.1K27me1, 54.8% of control) and lysine 56 tri-methylation (7.5% of control), as well as a trend suggesting increased histone 3 tyrosine 41 nitration. We further investigated the functional role of H3.1K27me1 and found that treatment of cultured microglial cells for 4 consecutive days with 1-10 μM of NCDM-64, a potent and selective inhibitor of lysine demethylase 7A, an enzyme responsible for the demethylation of H3K27me1, dose-dependently elevated its levels with a greater than a 2-fold increase observed at 10 μM compared to vehicle-treated control cells. Moreover, pre-treatment of mice with NCDM-64 (10 or 25 mg/kg/day, i.p.) prior to cisplatin treatment prevented the development of neuropathic pain in mice. The identification of specific chromatin marks in microglia associated with chronic pain may yield critical insight into the contribution of microglia to the development and maintenance of pain, and opens new avenues for the development of novel non-opioid therapeutics for the effective management of chronic pain. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ping Zhang
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Jennifer Guergues
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Amy R Alleyne
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Thomas J Cirino
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Owen Nadeau
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Colchester, VT, USA
| | - Ariana M Figueroa
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Heather M Stacy
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Takayoshi Suzuki
- The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Jay P McLaughlin
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - Stanley M Stevens
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Bin Liu
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, USA
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19
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Sun ZQ, Liu JF, Luo W, Wong CH, So KF, Hu Y, Chiu K. Lycium barbarum extract promotes M2 polarization and reduces oligomeric amyloid-β-induced inflammatory reactions in microglial cells. Neural Regen Res 2022; 17:203-209. [PMID: 34100457 PMCID: PMC8451572 DOI: 10.4103/1673-5374.314325] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Lycium barbarum (LB) is a traditional Chinese medicine that has been demonstrated to exhibit a wide variety of biological functions, such as antioxidation, neuroprotection, and immune modulation. One of the main mechanisms of Alzheimer's disease is that microglia activated by amyloid beta (Aβ) transform from the resting state to an M1 state and release pro-inflammatory cytokines to the surrounding environment. In the present study, immortalized microglial cells were pretreated with L. barbarum extract for 1 hour and then treated with oligomeric Aβ for 23 hours. The results showed that LB extract significantly increased the survival of oligomeric Aβ-induced microglial cells, downregulated the expression of M1 pro-inflammatory markers (inducible nitric oxide synthase, tumor necrosis factor α, interleukin-6, and interleukin-1β), and upregulated the expression of M2 anti-inflammatory markers (arginase-1, chitinase-like protein 3, and interleukin-4). LB extract also inhibited the oligomeric Aβ-induced secretion of tumor necrosis factor α, interleukin-6, and interleukin-1β in microglial cells. The results of in vitro cytological experiments suggest that, in microglial cells, LB extract can inhibit oligomeric Aβ-induced M1 polarization and concomitant inflammatory reactions, and promote M2 polarization.
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Affiliation(s)
- Zhong-Qing Sun
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Jin-Feng Liu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Wei Luo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Ching-Hin Wong
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Kwok-Fai So
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; State Key Laboratory of Brain and Cognitive Sciences; Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Yong Hu
- Department of Orthopaedics & Traumatology, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Kin Chiu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, China
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20
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Li Y, Glotfelty EJ, Karlsson T, Fortuno LV, Harvey BK, Greig NH. The metabolite GLP-1 (9-36) is neuroprotective and anti-inflammatory in cellular models of neurodegeneration. J Neurochem 2021; 159:867-886. [PMID: 34569615 DOI: 10.1111/jnc.15521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 09/17/2021] [Accepted: 09/22/2021] [Indexed: 12/23/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is best known for its insulinotropic action following food intake. Its metabolite, GLP-1 (9-36), was assumed biologically inactive because of low GLP-1 receptor (GLP-1R) affinity and non-insulinotropic properties; however, recent studies contradict this assumption. Increased use of FDA approved GLP-1 analogues for treating metabolic disorders and neurodegenerative diseases raises interest in GLP-1 (9-36)'s biological role. We use human SH-SY5Y neuroblastoma cells and a GLP-1R over-expressing variety (#9), in both undifferentiated and differentiated states, to evaluate the neurotrophic/neuroprotective effects of GLP-1 (9-36) against toxic glutamate exposure and other oxidative stress models (via the MTS, LDH or ROS assays). In addition, we examine GLP-1 (9-36)'s signaling pathways, including cyclic-adenosine monophosphate (cAMP), protein kinase-A (PKA), and 5' adenosine monophosphate-activated protein kinase (AMPK) via the use of ELISA, pharmacological inhibitors, or GLP-1R antagonist. Human HMC3 and mouse IMG microglial cell lines were used to study the anti-inflammatory effects of GLP-1 (9-36) against lipopolysaccharide (LPS) (via ELISA). Finally, we applied GLP-1 (9-36) to primary dissociation cultures challenged with α-synuclein or amyloid-β and assessed survival and morphology via immunochemistry. We demonstrate evidence of GLP-1R, cAMP, PKA, and AMPK-mediated neurotrophic and neuroprotective effects of GLP-1 (9-36). The metabolite significantly reduced IL-6 and TNF-α levels in HMC3 and IMG microglial cells, respectively. Lastly, we show mild but significant effects of GLP-1 (9-36) in primary neuron cultures challenged with α-synuclein or amyloid-β. These studies enhance understanding of GLP-1 (9-36)'s effects on the nervous system and its potential as a primary or complementary treatment in pathological contexts.
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Affiliation(s)
- Yazhou Li
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Elliot J Glotfelty
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA.,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tobias Karlsson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Lowella V Fortuno
- Molecular Mechanisms of Cellular Stress and Inflammation Unit, Integrative Neuroscience Department, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Brandon K Harvey
- Molecular Mechanisms of Cellular Stress and Inflammation Unit, Integrative Neuroscience Department, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | - Nigel H Greig
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
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21
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Pérez-Olives C, Rivas-Santisteban R, Lillo J, Navarro G, Franco R. Recent Advances in the Potential of Cannabinoids for Neuroprotection in Alzheimer's, Parkinson's, and Huntington's Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1264:81-92. [PMID: 33332005 DOI: 10.1007/978-3-030-57369-0_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Three prevalent neurodegenerative diseases, Parkinson's, Alzheimer's, and Huntington's are in need of symptomatic relief of slowing disease progression or both. This chapter focuses on the potential of cannabinoids to afford neuroprotection, i.e. avoid or retard neuronal death. The neuroprotective potential of cannabinoids is known from the work in animal models and is mediated by the two cannabinoid receptors (CB1/CB2) and eventually, by their heteromers, GPR55, orphan receptors (GPR3/GPR6/GPR12/GPR18), or PPARγ. Now, there is the time to translate the findings into patients. The chapter takes primarily into account advances since 2016 and addresses the issue of proving neuroprotection in humans. One recent discovery is the existence of activated microglia with neuroprotective phenotype; cannabinoids are good candidates to skew phenotype, especially via glial CB2 receptors (CB2R), whose targeting has, a priori, less side effects those targeting the CBs1 receptor (CB1R), which are expressed in both neurons and glia. The fact that a cannabis extract (SativexTM) is approved for human therapy, such that cannabis use will likely be legalized in many countries and different possibilities that cannabinoid pharmacology suggests a successful route of cannabinoids (natural or synthetic) all the way to be approved and used in the treatment of neurodegeneration.
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Affiliation(s)
- Catalina Pérez-Olives
- Molecular Neurobiology laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain
| | - Rafael Rivas-Santisteban
- Molecular Neurobiology laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED). Instituto de Salud Carlos III, Madrid, Spain
| | - Jaume Lillo
- Molecular Neurobiology laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED). Instituto de Salud Carlos III, Madrid, Spain
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED). Instituto de Salud Carlos III, Madrid, Spain. .,Department Biochemistry and Physiology. Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain.
| | - Rafael Franco
- Molecular Neurobiology laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED). Instituto de Salud Carlos III, Madrid, Spain.
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22
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Ibi D, Hirashima K, Kojima Y, Sumiya K, Kondo S, Yamamoto M, Ando T, Hiramatsu M. Preventive Effects of Continuous Betaine Intake on Cognitive Impairment and Aberrant Gene Expression in Hippocampus of 3xTg Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2020; 79:639-652. [PMID: 33337369 DOI: 10.3233/jad-200972] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The deposition of amyloid-β (Aβ) and hyperphosphorylation of tau are well-known as the pathophysiological features of Alzheimer's disease (AD), leading to oxidative stress and synaptic deficits followed by cognitive symptoms. We already demonstrated that betaine (glycine betaine) prevented cognitive impairment and hippocampal oxidative stress in mice intracerebroventricularly injected with an active fragment of Aβ, whereas the effect of betaine in chronic models of AD remains unknown. OBJECTIVE Our objective was to investigate the effects of chronic betaine intake on cognitive impairment and aberrant expression of genes involved in synapse and antioxidant activity in the hippocampus of a genetic AD model. METHODS We performed cognitive tests and RT-PCR in the hippocampus in 3xTg mice, a genetic AD model. RESULTS Cognitive impairment in the Y-maze and novel object recognition tests became evident in 3xTg mice at 9 months old, and not earlier, indicating that cognitive impairment in 3xTg mice developed age-dependently. To examine the preventive effect of betaine on such cognitive impairment, 3xTg mice were fed betaine-containing water for 3 months from 6 to 9 months old, and subsequently subjected to behavioral tests, in which betaine intake prevented the development of cognitive impairment in 3xTg mice. Additionally, the expression levels of genes involved in synapse and antioxidant activity were downregulated in hippocampus of 3xTg mice at 9 months old compared with age-matched wild-type mice, which were suppressed by betaine intake. CONCLUSION Betaine may be applicable as an agent preventing the progression of AD by improving the synaptic structure/function and/or antioxidant activity.
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Affiliation(s)
- Daisuke Ibi
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Kazuki Hirashima
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Yuya Kojima
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Kahori Sumiya
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Sari Kondo
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Mirai Yamamoto
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Toshihiro Ando
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
| | - Masayuki Hiramatsu
- Department of Chemical Pharmacology, Faculty of Pharmacy, Meijo University, Tenpaku-ku, Nagoya, Japan
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23
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Wu LH, Huang BR, Lai SW, Lin C, Lin HY, Yang LY, Lu DY. SIRT1 activation by minocycline on regulation of microglial polarization homeostasis. Aging (Albany NY) 2020; 12:17990-18007. [PMID: 33021962 PMCID: PMC7585093 DOI: 10.18632/aging.103542] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 05/25/2020] [Indexed: 01/24/2023]
Abstract
Sirtuin 1 (SIRT1) has been reported to be involved in the mechanisms underlying longevity and has also been indicated as a valuable regulator of age-related neurological disorders. Some natural products increase SIRT1 activity and stimulate deacetylation of various proteins. In the present study, SIRT1 overexpression by genetic modification or treatment with SIRT1 activators significantly inhibited the secretion of nitric oxide and expression of inducible nitric oxide synthase, cyclooxygenase 2, and proinflammatory mediator-interleukin 1β-in microglia. SIRT1 activation also decreased the levels of K379 acetyl-p53 and the protein inhibitor of activated Stat 1 expression in microglial cells. In addition, it dramatically promoted M2 polarization of microglia, which enhanced cell motility and altered phagocytic ability. We also used minocycline, a well-known inhibitor of microglial activation, to study the mechanism of SIRT1 signaling. Minocycline treatment decreased neuroinflammatory responses and promoted M2 polarization of microglia. It also reduced the acetyl-p53 level in the brain tissues in an inflammatory mouse model. Our findings demonstrated that SIRT1 participates in the maintenance of microglial polarization homeostasis and that minocycline exerts regulatory effects on SIRT1 activation. Therefore, our results indicate that SIRT1 activation may be a useful therapeutic target for the treatment of neuroinflammation-associated disorders.
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Affiliation(s)
- Ling-Hsuan Wu
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Bor-Ren Huang
- Department of Neurosurgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Sheng-Wei Lai
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Chingju Lin
- Department of Physiology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Hsiao-Yun Lin
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, China Medical University, Taichung, Taiwan,Laboratory for Neural Repair, China Medical University Hospital, Taichung, Taiwan,Biomedical Technology R&D Center, China Medical University Hospital, Taichung, Taiwan
| | - Dah-Yuu Lu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan,Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan
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24
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Cho HM, Ha TKQ, Doan TP, Dhodary B, An JP, Lee BW, Yang JL, Oh WK. Neuroprotective Effects of Triterpenoids from Camellia japonica against Amyloid β-Induced Neuronal Damage. JOURNAL OF NATURAL PRODUCTS 2020; 83:2076-2086. [PMID: 32569471 DOI: 10.1021/acs.jnatprod.9b00964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Alzheimer's disease (AD), a neurocognitive impairment affecting human mental capacity, is related to the accumulation of amyloid-β peptide (Aβ) and the hyperphosphorylation of tau protein. In addition to modern therapies approved for AD treatment, natural products with antioxidant and anti-inflammatory properties have been studied for their potential to prevent AD pathogenesis. Six new noroleanane triterpenoids from the fruit peels of Camellia japonica were isolated, and their structures were determined by diverse spectroscopic methods. The neuroprotective effects of the six new compounds were tested against Aβ-induced neurotoxicity and neuroinflammation in mouse hippocampal and microglial cells. In the model of HT22-transfected cells, compounds 1-4 showed strongly neuroprotective effects via antioxidant response element gene activation and decreased the level of glutamate uptake. Compounds 1-4 also appeared to have strong inhibitory effects on NO production in Aβ1-42-transfected BV2 microglial cells. A docking simulation study was used to explain the inhibitory effects of compounds 1-4 on β-secretase 1 (BACE1). Noroleanane triterpenoids 1-4 had potential neuroprotective and anti-inflammatory effects against Aβ-induced neuronal damage. The structure-activity relationships of the 30 oleanane triterpenoids from C. japonica were assessed in a model of Aβ1-42-transfected HT22 cells.
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Affiliation(s)
- Hyo-Moon Cho
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Thi-Kim-Quy Ha
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
- College of Natural Sciences, Cantho University, Campus II, Cantho City, Vietnam
| | - Thi-Phuong Doan
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Basanta Dhodary
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin-Pyo An
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Ba-Wool Lee
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Jun-Li Yang
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Won-Keun Oh
- Korea Bioactive Natural Material Bank, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
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25
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Cui W, Sun C, Ma Y, Wang S, Wang X, Zhang Y. Inhibition of TLR4 Induces M2 Microglial Polarization and Provides Neuroprotection via the NLRP3 Inflammasome in Alzheimer's Disease. Front Neurosci 2020; 14:444. [PMID: 32508567 PMCID: PMC7251077 DOI: 10.3389/fnins.2020.00444] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/09/2020] [Indexed: 11/18/2022] Open
Abstract
Accumulating evidence has indicated that activation of microglia and neuroinflammation reaction play a prominent role in Alzheimer’s disease (AD). Inhibition of toll-like receptor 4 (TLR4) has been shown to be associated with immune responses and brain damage, but its effects on AD remain unclear. This study mainly aimed to investigate the protective effect of TAK-242 (TLR4-specific inhibitor) on microglial polarization and neuroprotection in an AD mouse model and the underlying mechanisms. We found that APP/PS1 transgenic AD mice exhibited a dramatic increase in TLR4 levels concomitant with a significantly higher expression of inflammatory microglia compared to C57BL/6 wild-type mice. Furthermore, inhibition of TLR4 by TAK-242 administration significantly improved neurological function, decreased the level of Bax, and caused a significant reduction in the levels of M1-markers (iNOS and TNFα), while the expressions of M2-phenotype markers (Trem-2 and Arg-1) were increased both in vivo and in vitro. Furthermore, TAK-242 treatment enhanced BV2 microglial phagocytosis. Moreover, Aβ25–35 caused the upregulation of inflammatory cytokine production, MyD88, NF-kappaB-p65, and NLRP3, which could be ameliorated by NLRP3-siRNA or TAK-242. These findings indicated that TLR4 inhibition provided neuroprotection and promoted a microglial switch from the inflammatory M1 phenotype to the protective M2 phenotype in AD. The mechanism involved may be related to modulation of the MyD88/NF-kappaB/NLRP3 signaling pathway.
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Affiliation(s)
- Weigang Cui
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, China.,Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, China
| | - Chunli Sun
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, China
| | - Yuqi Ma
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, China
| | - Songtao Wang
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, China
| | - Xianwei Wang
- Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, China
| | - Yinghua Zhang
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Molecular Neurology, Xinxiang Medical University, Xinxiang, China
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26
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Deep proteome profiling reveals novel pathways associated with pro-inflammatory and alcohol-induced microglial activation phenotypes. J Proteomics 2020; 220:103753. [PMID: 32200115 DOI: 10.1016/j.jprot.2020.103753] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/09/2020] [Accepted: 03/17/2020] [Indexed: 12/13/2022]
Abstract
Microglia, the resident immune cells of the brain, can exhibit a broad range of activation phenotypes, many of which have been implicated in several diseases and disorders of the central nervous system including those related to alcohol abuse. Given the complexity of global-scale molecular changes that define microglial activation, accurate phenotypic classification in the context of alcohol exposure is still lacking. We employed an optimized method for deep, quantitative proteome profiling of primary microglia in order to characterize their response to acute exposure to alcohol (ethanol) as well as the pro-inflammatory driver and TLR4 agonist, LPS. From this analysis, 5,062 total proteins were identified where 4,857 and 4,928 of those proteins were quantifiable by label-free quantitation in ethanol and LPS treatment groups, respectively. This study highlights the subtle, yet significant proteomic changes that occur in ethanol-treated microglia, which do not align with the robust pro-inflammatory phenotype induced by TLR4 activation. Specifically, our results indicate inhibition of several upstream regulators associated with inflammation, opposing effects on pathways such as phagocytosis upon comparison to TLR4-mediated pro-inflammatory phenotype, and a potential metabolic shift associated with increased expression of proteins related to OXPHOS and lipid homeostasis. Data are available via ProteomeXchange with identifier PXD14466. SIGNIFICANCE: Alcohol abuse has a significant impact on the central nervous system, which includes the pathophysiological mechanisms resulting from glial cell activation. Microglia, in particular, are the resident immune cells of the brain and exhibit a broad range of activation phenotypes. The molecular changes that drive microglial activation phenotype are complex and have yet to be fully characterized in the context of alcohol exposure. Our study highlights the first and most comprehensive characterization of alcohol-induced proteomic changes in primary microglia to date and has shed light on novel immune-related and metabolic pathways that are altered due to alcohol exposure. The results from this study provide an important foundation for future work aimed to understand the complexity of alcohol-induced microglial activation in vivo and other translational models of acute and chronic alcohol exposure.
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27
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Nnah IC, Lee CH, Wessling-Resnick M. Iron potentiates microglial interleukin-1β secretion induced by amyloid-β. J Neurochem 2020; 154:177-189. [PMID: 31693761 DOI: 10.1111/jnc.14906] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 10/15/2019] [Accepted: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is characterized by accumulation of amyloid-beta (Aβ) senile plaques in patients' brain tissues. Elevated levels of interleukin-1beta (IL-1β) have been identified in cerebrospinal fluid of living AD patients and in animal models of AD. Increased expression of IL-1β and iron accumulation have been identified in microglial cells that cluster around amyloid plaques in AD mouse models and post-mortem brain tissues of AD patients. The goals of this study were to determine the effects of Aβ on the secretion of IL-1β by microglial cells and whether iron status influences this pro-inflammatory signaling cue. Immortalized microglial (IMG) cells were incubated with Aβ with or without iron. qRT-PCR and western blot analyses showed that Aβ induces biosynthesis of IL-1β by IMG cells. IMG cells secrete the mature form of IL-1β in a caspase 1-dependent manner. Incubation with iron provoked a greater pro-inflammatory response. Inhibition of the iron transporter divalent metal transporter 1 protected IMG cells against Aβ-induced inflammation. Potentiation of Aβ-elicited IL-1β induction by iron was also antagonized by ROS inhibitors, supporting the model that divalent metal transporter 1-mediated iron loading and subsequent increase in ROS contribute to the inflammatory effects of Aβ in microglia. Immunoblotting and immunofluorescence microscopy indicate that iron enhances Aβ activation of NF-κB signaling to promote IL-1β synthesis. These results support the hypothesis that Aβ stimulates IL-1β expression by activating NF-κB signaling in microglia cells. Most importantly, iron appears to exacerbate the pro-inflammatory effects of Aβ to increase IL-1β levels.
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Affiliation(s)
- Israel C Nnah
- Department of Molecular Metabolism, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Chih-Hao Lee
- Department of Molecular Metabolism, Harvard TH Chan School of Public Health, Boston, MA, USA
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28
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Medrano-Jiménez E, Jiménez-Ferrer Carrillo I, Pedraza-Escalona M, Ramírez-Serrano CE, Álvarez-Arellano L, Cortés-Mendoza J, Herrera-Ruiz M, Jiménez-Ferrer E, Zamilpa A, Tortoriello J, Pedraza-Alva G, Pérez-Martínez L. Malva parviflora extract ameliorates the deleterious effects of a high fat diet on the cognitive deficit in a mouse model of Alzheimer's disease by restoring microglial function via a PPAR-γ-dependent mechanism. J Neuroinflammation 2019; 16:143. [PMID: 31291963 PMCID: PMC6617588 DOI: 10.1186/s12974-019-1515-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 06/10/2019] [Indexed: 12/12/2022] Open
Abstract
Background Alzheimer’s disease (AD) is a neuropathology strongly associated with the activation of inflammatory pathways. Accordingly, inflammation resulting from obesity exacerbates learning and memory deficits in humans and in animal models of AD. Consequently, the long-term use of non-steroidal anti-inflammatory agents diminishes the risk for developing AD, but the side effects produced by these drugs limit their prophylactic use. Thus, plants natural products have become an excellent option for modern therapeutics. Malva parviflora is a plant well known for its anti-inflammatory properties. Methods The present study was aimed to determine the anti-inflammatory potential of M. parviflora leaf hydroalcoholic extract (MpHE) on AD pathology in lean and obese transgenic 5XFAD mice, a model of familial AD. The inflammatory response and Amyloid β (Aβ) plaque load in lean and obese 5XFAD mice untreated or treated with MpHE was evaluated by immunolocalization (Iba-1 and GFAP) and RT-qPCR (TNF) assays and thioflavin-S staining, respectively. Spatial learning memory was assessed by the Morris Water Maze behavioral test. Microglia phagocytosis capacity was analyzed in vivo and by ex vivo and in vitro assays, and its activation by morphological changes (phalloidin staining) and expression of CD86, Mgl1, and TREM-2 by RT-qPCR. The mechanism triggered by the MpHE was characterized in microglia primary cultures and ex vivo assays by immunoblot (PPAR-γ) and RT-qPCR (CD36) and in vivo by flow cytometry, using GW9662 (PPAR-γ inhibitor) and pioglitazone (PPAR-γ agonist). The presence of bioactive compounds in the MpHE was determined by HPLC. Results MpHE efficiently reduced astrogliosis, the presence of insoluble Aβ peptides in the hippocampus and spatial learning impairments, of both, lean, and obese 5XFAD mice. This was accompanied by microglial cells accumulation around Aβ plaques in the cortex and the hippocampus and decreased expression of M1 inflammatory markers. Consistent with the fact that the MpHE rescued microglia phagocytic capacity via a PPAR-γ/CD36-dependent mechanism, the MpHE possess oleanolic acid and scopoletin as active phytochemicals. Conclusions M. parviflora suppresses neuroinflammation by inhibiting microglia pro-inflammatory M1 phenotype and promoting microglia phagocytosis. Therefore, M. parviflora phytochemicals represent an alternative to prevent cognitive impairment associated with a metabolic disorder as well as an effective prophylactic candidate for AD progression. Electronic supplementary material The online version of this article (10.1186/s12974-019-1515-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elisa Medrano-Jiménez
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Itzia Jiménez-Ferrer Carrillo
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Martha Pedraza-Escalona
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Cristina E Ramírez-Serrano
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Lourdes Álvarez-Arellano
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México.,Present address: CONACYT-Hospital Infantil de México Federico Gómez, CP 06720, Ciudad de México, México
| | - Javier Cortés-Mendoza
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Maribel Herrera-Ruiz
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social (IMSS), Argentina No. 1, CP 62790, Xochitepec, Morelos, México
| | - Enrique Jiménez-Ferrer
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social (IMSS), Argentina No. 1, CP 62790, Xochitepec, Morelos, México
| | - Alejandro Zamilpa
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social (IMSS), Argentina No. 1, CP 62790, Xochitepec, Morelos, México
| | - Jaime Tortoriello
- Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social (IMSS), Argentina No. 1, CP 62790, Xochitepec, Morelos, México
| | - Gustavo Pedraza-Alva
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México
| | - Leonor Pérez-Martínez
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A.P. 510-3, CP, 62210, Cuernavaca, Morelos, México.
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Tom S, Rane A, Katewa AS, Chamoli M, Matsumoto RR, Andersen JK, Chinta SJ. Gedunin Inhibits Oligomeric Aβ1–42-Induced Microglia Activation Via Modulation of Nrf2-NF-κB Signaling. Mol Neurobiol 2019; 56:7851-7862. [DOI: 10.1007/s12035-019-1636-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/06/2019] [Indexed: 12/20/2022]
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30
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Guergues J, Zhang P, Liu B, Stevens SM. Improved Methodology for Sensitive and Rapid Quantitative Proteomic Analysis of Adult-Derived Mouse Microglia: Application to a Novel In Vitro Mouse Microglial Cell Model. Proteomics 2019; 19:e1800469. [PMID: 30980500 DOI: 10.1002/pmic.201800469] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/26/2019] [Indexed: 12/30/2022]
Abstract
Microglia, as the resident brain immune cells, can exhibit a broad range of activation phenotypes, which have been implicated in a multitude of central nervous system disorders. Current widely studied microglial cell lines are mainly derived from neonatal rodent brain that can limit their relevance to homeostatic function and disease-related neuroimmune responses in the adult brain. Recently, an adult mouse brain-derived microglial cell line has been established; however, a comprehensive proteome dataset remains lacking. Here, an optimization method for sensitive and rapid quantitative proteomic analysis of microglia is described that involves suspension trapping (S-Trap) for efficient and reproducible protein extraction from a limited number of microglial cells expected from an adult mouse brain (≈300 000). Using a 2-h gradient on a 75-cm UPLC column with a modified data dependent acquisition method on a hybrid quadrupole-Orbitrap mass spectrometer, 4855 total proteins have been identified where 4698 of which are quantifiable by label-free quantitation with a median and average coefficient of variation (CV) of 6.7% and 10.6%, respectively. This dataset highlights the high depth of proteome coverage and related quantitation precision of the adult-derived microglial proteome including proteins associated with several key pathways related to immune response. Data are available via ProteomeXchange with identifier PXD012006.
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Affiliation(s)
- Jennifer Guergues
- Department of Cell Biology, Microbiology, and Molecular Biology, Department of Biology, University of South Florida, Tampa, FL, 33620, USA.,Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Colchester, VT, 05446, USA
| | - Ping Zhang
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Bin Liu
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Stanley M Stevens
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Colchester, VT, 05446, USA
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31
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Ibi D, Tsuchihashi A, Nomura T, Hiramatsu M. Involvement of GAT2/BGT-1 in the preventive effects of betaine on cognitive impairment and brain oxidative stress in amyloid β peptide-injected mice. Eur J Pharmacol 2019; 842:57-63. [DOI: 10.1016/j.ejphar.2018.10.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/13/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022]
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32
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Timmerman R, Burm SM, Bajramovic JJ. An Overview of in vitro Methods to Study Microglia. Front Cell Neurosci 2018; 12:242. [PMID: 30127723 PMCID: PMC6087748 DOI: 10.3389/fncel.2018.00242] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/18/2018] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation is a common feature in neurodegenerative diseases and strategies to modulate neuroinflammatory processes are increasingly considered as therapeutic options. In such strategies, glia cells rather than neurons represent the cellular targets. Microglia, the resident macrophages of the central nervous system, are principal players in neuroinflammation and detailed cellular biological knowledge of this particular cell type is therefore of pivotal importance. The last decade has shed new light on the origin, characteristics and functions of microglia, underlining the need for specific in vitro methodology to study these cells in detail. In this review we provide a comprehensive overview of existing methodology such as cell lines, stem cell-derived microglia and primary dissociated cell cultures, as well as discuss recent developments. As there is no in vitro method available yet that recapitulates all hallmarks of adult homeostatic microglia, we also discuss the advantages and limitations of existing models across different species.
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Affiliation(s)
- Raissa Timmerman
- Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, Netherlands
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33
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Secretome from SH-SY5Y APP Swe cells trigger time-dependent CHME3 microglia activation phenotypes, ultimately leading to miR-21 exosome shuttling. Biochimie 2018; 155:67-82. [PMID: 29857185 DOI: 10.1016/j.biochi.2018.05.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/27/2018] [Indexed: 01/08/2023]
Abstract
Exosome-mediated intercellular communication has been increasingly recognized as having a broad impact on Alzheimer's disease (AD) pathogenesis. Still, limited information exists regarding their "modus operandi", as it critically depends on exosomal cargo, environmental context and target cells. Therefore, a more thorough understanding of the role of exosomes from different cell types as mediators of neuroinflammation in AD context is a decisive step to open avenues for innovative and efficient therapies. In this study, we demonstrate that SH-SY5Y cells transfected with the Swedish mutant of APP695 (SHSwe) remarkably express increased inflammatory markers, combined with higher APP and Aβ1-40 production, when compared to naïve SH-SY5Y (SH) cells. Although exerting an early clearance effect on extracellular APP and Aβ accumulation when in co-culture with SHSwe cells, human CHME3 microglia gradually lose such property, and express both pro-inflammatory (iNOS, IL-1β, TNF-α, MHC class II, IL-6) and pro-resolving genes (IL-10 and Arginase 1), while also evidence increased senescence-associated β-galactosidase activity. Interestingly, upregulation of inflammatory-associated miRNA (miR)-155, miR-146a and miR-124 by SHSwe secretome shows to be time-dependent and to inversely correlate with their respective targets (SOCS-1, IRAK1 and C/EBP-α). We report that microglia also internalize exosomes released from SHSwe cells, which are enriched in miR-155, miR-146a, miR-124, miR-21 and miR-125b and recapitulate the cells of origin. Furthermore, we show that SHSwe-derived exosomes are capable of inducing acute and delayed microglial upregulation of TNF-α, HMGB1 and S100B pro-inflammatory markers, from which only S100B is found on their derived exosomes. Most importantly, our data reveal that miR-21 is a consistent biomarker that is found not only in SHSwe cells and in their released exosomes, but also in the recipient CHME3 microglia and derived exosomes. This work contributes to the increased understanding of neuron-microglia communication and exosome-mediated neuroinflammation in AD, while highlights miR-21 as a promising biomarker/target for therapeutic intervention.
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McCarthy RC, Sosa JC, Gardeck AM, Baez AS, Lee CH, Wessling-Resnick M. Inflammation-induced iron transport and metabolism by brain microglia. J Biol Chem 2018; 293:7853-7863. [PMID: 29610275 PMCID: PMC5961037 DOI: 10.1074/jbc.ra118.001949] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/29/2018] [Indexed: 01/08/2023] Open
Abstract
Microglia are immune cells of the central nervous system and are implicated in brain inflammation. However, how brain microglia modulate transport and metabolism of the essential metal iron in response to pro- and anti-inflammatory environmental cues is unclear. Here, we characterized uptake of transferrin (Tf)-bound iron (TBI) and non-Tf-bound iron (NTBI) by immortalized microglial (IMG) cells. We found that these cells preferentially take up NTBI in response to the proinflammatory stimulus lipopolysaccharide (LPS) or β-amyloid (Aβ). In contrast, the anti-inflammatory cytokine interleukin 4 (IL-4) promoted TBI uptake. Concordant with these functional data, levels of the Tf receptor (TfR) in IMG cells were up-regulated in response to IL-4, whereas divalent metal transporter-1 (DMT1) and ferritin levels increased in response to LPS or Aβ. Similar changes in expression were confirmed in isolated primary adult mouse microglia treated with pro- or anti-inflammatory inducers. LPS-induced changes in IMG cell iron metabolism were accompanied by notable metabolic changes, including increased glycolysis and decreased oxidative respiration. Under these conditions, the extracellular acidification rate was increased, compatible with changes in the cellular microenvironment that would support the pH-dependent function of DMT1. Moreover, LPS increased heme oxygenase-1 (HO1) expression in IMG cells, and iron released because of HO1 activity increased the intracellular labile free-iron pool. Together, this evidence indicates that brain microglia preferentially acquire iron from Tf or from non-Tf sources, depending on their polarization state; that NTBI uptake is enhanced by the proinflammatory response; and that under these conditions microglia sequester both extra- and intracellular iron.
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Affiliation(s)
- Ryan C McCarthy
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Jose Carlo Sosa
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Andrew M Gardeck
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Andrew S Baez
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Chih-Hao Lee
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Marianne Wessling-Resnick
- From the Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
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Zeng Q, Hu C, Qi R, Lu D. PYNOD reduces microglial inflammation and consequent neurotoxicity upon lipopolysaccharides stimulation. Exp Ther Med 2018; 15:5337-5343. [PMID: 29904414 PMCID: PMC5996706 DOI: 10.3892/etm.2018.6108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 03/28/2018] [Indexed: 01/01/2023] Open
Abstract
PYNOD, a nod-like receptors (NLR)-like protein, was indicated to inhibit NF-κB activation, caspase-1-mediated interleukin (IL)-1β release and cell apoptosis in a dose-dependent manner. Exogenous addition of recombinant PYNOD to mixed glial cultures may suppress caspase-1 activation and IL-1β secretion induced by Aβ. However, to the best of our knowledge, there no study has focused on the immunoregulatory effects of PYNOD specifically in microglia. The present study aimed to explore the roles of PYNOD involved in the lipopolysaccharides (LPS)-induced microglial inflammation and consequent neurotoxicity. Murine microglial BV-2 cells were transfected with pEGFP-C2-PYNOD (0–5.0 µg/ml) for 24 h and incubated with or without LPS (1 µg/ml) for a further 24 h. Cell viability was determined using MTT assay and the secretion of nitric oxide (NO), IL-1β and caspase-1 was measured using the Griess method or ELISA. Protein expression levels of NF-κB p65 and inducible nitric oxide synthase (iNOS) were detected by immunofluorescent staining and/or western blot analysis. Co-culture of BV-2 cells with human neuroblastoma cell line SK-N-SH was performed in Transwell plates and the cell viability and apoptosis (using flow cytometry) of SK-N-SH cells were determined. Results indicated that PYNOD overexpression inhibited NO secretion and iNOS protein expression induced by LPS in BV-2 cells, with no detectable cytotoxicity. PYNOD overexpression also reduced the secretion of IL-1β and caspase-1 from BV-2 cells upon LPS stimulation. These effects were dose-dependent. Additionally, PYNOD overexpression prevented LPS-induced nuclear translocation of NF-κB p65 in BV-2 cells. The growth-inhibitory and apoptosis-promoting effects of BV-2 cells towards SK-N-SH cells were alleviated as a result of PYNOD overexpression. In conclusion, PYNOD may mitigate microglial inflammation and consequent neurotoxicity.
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Affiliation(s)
- Qi Zeng
- Department of Ultrasonic Diagnosis, The First Affiliated Hospital of Gannan Medical College, Ganzhou, Jiangxi 341000, P.R. China
| | - Chaofeng Hu
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Renbin Qi
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Daxiang Lu
- Key Laboratory of State Administration of Traditional Chinese Medicine of The People's Republic of China, Institute of Brain Research, Department of Pathophysiology, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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36
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Kim SM, McIlwraith EK, Chalmers JA, Belsham DD. Palmitate Induces an Anti-Inflammatory Response in Immortalized Microglial BV-2 and IMG Cell Lines that Decreases TNFα Levels in mHypoE-46 Hypothalamic Neurons in Co-Culture. Neuroendocrinology 2018; 107:387-399. [PMID: 30352432 DOI: 10.1159/000494759] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Elevated levels of saturated fatty acids (SFA) induce a state of neuroinflammation in the hypothalamus. It has been suggested that microglia sense palmitate, a prevalent circulating SFA, and act as mediators of this inflammatory process by communicating with neurons, particularly those involved in appetite regulation. In this study, we examined the inflammatory response to palmitate in immortalized microglial cell lines, BV-2 and IMG, and the subsequent effects on inflammatory gene expression in a model of NPY/AgRP neurons, mHypoE-46. METHODS The BV-2 cells were treated with 50 µM palmitate for 4 and 24 h, and the transcriptional regulation of markers for inflammation and cellular stress was assessed using an RT2 Profiler PCR Array. Select genes were verified with qRT-PCR. The BV-2 and IMG cells were then co-cultured using 1.0-µm cell culture inserts with an immortalized hypothalamic cell line, mHypoE-46, to investigate potential intercellular communication between microglia and neurons. RESULTS We found that palmitate increased the mRNA levels of specific inflammatory genes, and a general anti-inflammatory profile was revealed in the microglia cells. The mRNA changes in TNFα at 4 and 24 h in BV-2 cells were abrogated with the toll-like receptor 4 (TLR4) inhibitor, TAK-242, indicating the involvement of TLR4. Co-culture of mHypoE-46 neurons with microglia pre-treated with palmitate resulted in repression of TNFα expression in the hypothalamic neurons. As palmitate significantly increased IL-13 expression in microglia, the effect of this cytokine was tested in mHypoE-46 neurons. The addition of IL-13 to neuronal cultures normalized the palmitate-mediated increase in IL-6 and AgRP expression, suggesting that microglia may protect surrounding neurons, at least in part, through the release of IL-13. CONCLUSIONS These results suggest a potential anti-inflammatory role of microglia towards the palmitate-induced neuroinflammation, and potentially energy homeostasis, in hypothalamic neurons.
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Affiliation(s)
- Stephanie M Kim
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Emma K McIlwraith
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jennifer A Chalmers
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Denise D Belsham
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario,
- Departments of Medicine and Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, Ontario,
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37
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Seigel GM, Manohar S, Bai YY, Ding D, Salvi R. An immortalized microglial cell line (Mocha) derived from rat cochlea. Mol Cell Neurosci 2017; 85:202-210. [PMID: 29109020 DOI: 10.1016/j.mcn.2017.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/19/2017] [Accepted: 11/02/2017] [Indexed: 01/18/2023] Open
Abstract
Microglia are glial-immune cells that are essential for the function and survival of the central nervous system. Microglia not only protect neural tissues from immunological insults, but also play a critical role in neural development and repair. However, little is known about the biology of microglia in the cochlea, the auditory portion of the inner ear. In this study, we detected TMEM119+, CD11b+, CD45+ and Iba1+ populations of cells in the rat cochlea, particularly in Rosenthal's canal, inner sulcus and stria vascularis. Next, we isolated and enriched the population of CD11b+ cells from the cochlea and immortalized these cells with the 12S E1A gene of adenovirus in a replication-incompetent retroviral vector to derive a novel microglial cell line, designated Mocha (microglia of the cochlea). The resulting Mocha cells express a number of markers consistent with microglia and respond to lipopolysaccharide (LPS) stimulation by upregulation of genes (Cox2, ICAM-1, Il6r, Ccl2, Il13Ra and Il15Ra) as well as releasing cytokines (IL-1beta, IL-12, IL-13 and RANTES). As evidence of microglial function, Mocha cells phagocytose fluorescent beads at 37°C, but not at 4°C. The expression pattern of microglial markers in Mocha cells suggests that immortalization leads to a more primitive phenotype, a common phenomenon in immortalized cell lines. In summary, Mocha cells display key characteristics of microglia and are now available as a useful model system for the study of cochlear microglial behavior, both in vitro and in vivo.
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Affiliation(s)
- G M Seigel
- University at Buffalo, Center For Hearing & Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States.
| | - S Manohar
- University at Buffalo, Center For Hearing & Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States.
| | - Y Y Bai
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China.
| | - D Ding
- University at Buffalo, Center For Hearing & Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States.
| | - R Salvi
- University at Buffalo, Center For Hearing & Deafness, 3435 Main Street, Cary 137, Buffalo, NY 14214, United States; Department of Audiology and Speech-Language Pathology, Asia University, Taichung, Taiwan.
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Environmental Enrichment Potently Prevents Microglia-Mediated Neuroinflammation by Human Amyloid β-Protein Oligomers. J Neurosci 2017; 36:9041-56. [PMID: 27581448 DOI: 10.1523/jneurosci.1023-16.2016] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 07/06/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Microglial dysfunction is increasingly recognized as a key contributor to the pathogenesis of Alzheimer's disease (AD). Environmental enrichment (EE) is well documented to enhance neuronal form and function, but almost nothing is known about whether and how it alters the brain's innate immune system. Here we found that prolonged exposure of naive wild-type mice to EE significantly altered microglial density and branching complexity in the dentate gyrus of hippocampus. In wild-type mice injected intraventricularly with soluble Aβ oligomers (oAβ) from hAPP-expressing cultured cells, EE prevented several morphological features of microglial inflammation and consistently prevented oAβ-mediated mRNA changes in multiple inflammatory genes both in vivo and in primary microglia cultured from the mice. Microdialysis in behaving mice confirmed that EE normalized increases in the extracellular levels of the key cytokines (CCL3, CCL4, TNFα) identified by the mRNA analysis. Moreover, EE prevented the changes in microglial gene expression caused by ventricular injection of oAβ extracted directly from AD cerebral cortex. We conclude that EE potently alters the form and function of microglia in a way that prevents their inflammatory response to human oAβ, suggesting that prolonged environmental enrichment could protect against AD by modulating the brain's innate immune system. SIGNIFICANCE STATEMENT Environmental enrichment (EE) is a potential therapy to delay Alzheimer's disease (AD). Microglial inflammation is associated with the progression of AD, but the influence of EE on microglial inflammation is unclear. Here we systematically applied in vivo methods to show that EE alters microglia in the dentate gyrus under physiological conditions and robustly prevents microglial inflammation induced by human Aβ oligomers, as shown by neutralized microglial inflammatory morphology, mRNA changes, and brain interstitial fluid cytokine levels. Our findings suggest that EE alters the innate immune system and could serve as a therapeutic approach to AD and provide new targets for drug discovery. Further, we propose that the therapeutic benefits of EE could extend to other neurodegenerative diseases involving microglial inflammation.
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39
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Alberti TB, Barbosa WLR, Vieira JLF, Raposo NRB, Dutra RC. (-)-β-Caryophyllene, a CB2 Receptor-Selective Phytocannabinoid, Suppresses Motor Paralysis and Neuroinflammation in a Murine Model of Multiple Sclerosis. Int J Mol Sci 2017; 18:ijms18040691. [PMID: 28368293 PMCID: PMC5412277 DOI: 10.3390/ijms18040691] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/18/2017] [Accepted: 03/20/2017] [Indexed: 12/05/2022] Open
Abstract
(−)-β-caryophyllene (BCP), a cannabinoid receptor type 2 (CB2)-selective phytocannabinoid, has already been shown in precedent literature to exhibit both anti-inflammatory and analgesic effects in mouse models of inflammatory and neuropathic pain. Herein, we endeavored to investigate the therapeutic potential of BCP on experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). Furthermore, we sought to demonstrate some of the mechanisms that underlie the modulation BCP exerts on autoimmune activated T cells, the pro-inflammatory scenery of the central nervous system (CNS), and demyelination. Our findings demonstrate that BCP significantly ameliorates both the clinical and pathological parameters of EAE. In addition, data hereby presented indicates that mechanisms underlying BCP immunomodulatory effect seems to be linked to its ability to inhibit microglial cells, CD4+ and CD8+ T lymphocytes, as well as protein expression of pro-inflammatory cytokines. Furthermore, it diminished axonal demyelination and modulated Th1/Treg immune balance through the activation of CB2 receptor. Altogether, our study represents significant implications for clinical research and strongly supports the effectiveness of BCP as a novel molecule to target in the development of effective therapeutic agents for MS.
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MESH Headings
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Cannabinoid Receptor Agonists/pharmacology
- Cytokines/metabolism
- Demyelinating Diseases/prevention & control
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/physiopathology
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Female
- Humans
- Hyperalgesia/prevention & control
- Mice, Inbred C57BL
- Microglia/drug effects
- Microglia/metabolism
- Multiple Sclerosis/metabolism
- Multiple Sclerosis/physiopathology
- Multiple Sclerosis/prevention & control
- Neurogenic Inflammation/metabolism
- Neurogenic Inflammation/physiopathology
- Neurogenic Inflammation/prevention & control
- Paralysis/metabolism
- Paralysis/physiopathology
- Paralysis/prevention & control
- Polycyclic Sesquiterpenes
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/metabolism
- Sesquiterpenes/pharmacology
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- Th1 Cells/drug effects
- Th1 Cells/immunology
- Th1 Cells/metabolism
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Affiliation(s)
- Thaís Barbosa Alberti
- Laboratory of Autoimmunity and Immunopharmacology (LAIF), Department of Health Sciences, Center of Araranguá, Federal University of Santa Catarina, Araranguá 88906-072, Brazil.
| | | | | | - Nádia Rezende Barbosa Raposo
- Research and Innovation in Health Sciences (NUPICS), Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil.
| | - Rafael Cypriano Dutra
- Laboratory of Autoimmunity and Immunopharmacology (LAIF), Department of Health Sciences, Center of Araranguá, Federal University of Santa Catarina, Araranguá 88906-072, Brazil.
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40
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Sousa C, Biber K, Michelucci A. Cellular and Molecular Characterization of Microglia: A Unique Immune Cell Population. Front Immunol 2017; 8:198. [PMID: 28303137 PMCID: PMC5332364 DOI: 10.3389/fimmu.2017.00198] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/09/2017] [Indexed: 12/26/2022] Open
Abstract
Microglia are essential for the development and function of the adult brain. Microglia arise from erythro-myeloid precursors in the yolk sac and populate the brain rudiment early during development. Unlike monocytes that are constantly renewed from bone marrow hematopoietic stem cells throughout life, resident microglia in the healthy brain persist during adulthood via constant self-renewal. Their ontogeny, together with the absence of turnover from the periphery and the singular environment of the central nervous system, make microglia a unique cell population. Supporting this notion, recent genome-wide transcriptional studies revealed specific gene expression profiles clearly distinct from other brain and peripheral immune cells. Here, we highlight the breakthrough studies that, over the last decades, helped elucidate microglial cell identity, ontogeny, and function. We describe the main techniques that have been used for this task and outline the crucial milestones that have been achieved to reach our actual knowledge of microglia. Furthermore, we give an overview of the “microgliome” that is currently emerging thanks to the constant progress in the modern profiling techniques.
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Affiliation(s)
- Carole Sousa
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, Section Molecular Psychiatry, University of Freiburg, Freiburg, Germany; Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alessandro Michelucci
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg
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Duffy CM, Ahmed S, Yuan C, Mavanji V, Nixon JP, Butterick T. Microglia as a Surrogate Biosensor to Determine Nanoparticle Neurotoxicity. J Vis Exp 2016. [PMID: 27805611 DOI: 10.3791/54662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nanoparticles found in air pollutants can alter neurotransmitter profiles, increase neuroinflammation, and alter brain function. Therefore, the assay described here will aid in elucidating the role of microglia in neuroinflammation and neurodegenerative diseases. The use of microglia, resident immune cells of the brain, as a surrogate biosensor provides novel insight into how inflammatory responses mediate neuronal insults. Here, we utilize an immortalized murine microglial cell line, designated BV2, and describe a method for nanoparticle exposure using silver nanoparticles (AgNPs) as a standard. We describe how to expose microglia to nanoparticles, how to remove nanoparticles from supernatant, and how to use supernatant from activated microglia to determine toxicity, using hypothalamic cell survival as a measure. Following AgNP exposure, BV2 microglial activation was validated using a tumor necrosis factor alpha (TNF-α) enzyme linked immunosorbent assay (ELISA). The supernatant was filtered to remove the AgNP and to allow cytokines and other secreted factors to remain in the conditioned media. Hypothalamic cells were then exposed to supernatant from AgNP activated microglia and survival of neurons was determined using a resazurin-based fluorescent assay. This technique is useful for utilizing microglia as a surrogate biomarker of neuroinflammation and determining the effect of neuroinflammation on other cell types.
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Affiliation(s)
- Cayla M Duffy
- Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota
| | | | - Ce Yuan
- Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota; Biomedical Informatics and Computational Biology Program, University of Minnesota
| | | | - Joshua P Nixon
- Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota
| | - Tammy Butterick
- Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota; Minnesota Obesity Center, University of Minnesota;
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Regulation of divalent metal transporter-1 by serine phosphorylation. Biochem J 2016; 473:4243-4254. [PMID: 27681840 PMCID: PMC5103878 DOI: 10.1042/bcj20160674] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/22/2016] [Accepted: 09/28/2016] [Indexed: 01/14/2023]
Abstract
Divalent metal transporter-1 (DMT1) mediates dietary iron uptake across the intestinal mucosa and facilitates peripheral delivery of iron released by transferrin in the endosome. Here, we report that classical cannabinoids (Δ9-tetrahydrocannabinol, Δ9-THC), nonclassical cannabinoids (CP 55,940), aminoalkylindoles (WIN 55,212-2) and endocannabinoids (anandamide) reduce 55Fe and 54Mn uptake by HEK293T(DMT1) cells stably expressing the transporter. siRNA knockdown of cannabinoid receptor type 2 (CB2) abrogated inhibition. CB2 is a G-protein (GTP-binding protein)-coupled receptor that negatively regulates signal transduction cascades involving serine/threonine kinases. Immunoprecipitation experiments showed that DMT1 is serine-phosphorylated under basal conditions, but that treatment with Δ9-THC reduced phosphorylation. Site-directed mutation of predicted DMT1 phosphosites further showed that substitution of serine with alanine at N-terminal position 43 (S43A) abolished basal phosphorylation. Concordantly, both the rate and extent of 55Fe uptake in cells expressing DMT1(S43A) was reduced compared with those expressing wild-type DMT1. Among kinase inhibitors that affected DMT1-mediated iron uptake, staurosporine also reduced DMT1 phosphorylation confirming a role for serine phosphorylation in iron transport regulation. These combined data indicate that phosphorylation at serine 43 of DMT1 promotes transport activity, whereas dephosphorylation is associated with loss of iron uptake. Since anti-inflammatory actions mediated through CB2 would be associated with reduced DMT1 phosphorylation, we postulate that this pathway provides a means to reduce oxidative stress by limiting iron uptake.
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Maysinger D, Zhang I. Nutritional and Nanotechnological Modulators of Microglia. Front Immunol 2016; 7:270. [PMID: 27471505 PMCID: PMC4945637 DOI: 10.3389/fimmu.2016.00270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022] Open
Abstract
Microglia are the essential responders to alimentary, pharmacological, and nanotechnological immunomodulators. These neural cells play multiple roles as surveyors, sculptors, and guardians of essential parts of complex neural circuitries. Microglia can play dual roles in the central nervous system; they can be deleterious and/or protective. The immunomodulatory effects of alimentary components, gut microbiota, and nanotechnological products have been investigated in microglia at the single-cell level and in vivo using intravital imaging approaches, and different biochemical assays. This review highlights some of the emerging questions and topics from studies involving alimentation, microbiota, nanotechnological products, and associated problems in this area of research. Some of the advantages and limitations of in vitro and in vivo models used to study the neuromodulatory effects of these factors, as well as the merits and pitfalls of intravital imaging modalities employed are presented.
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Affiliation(s)
- Dusica Maysinger
- Department of Pharmacology and Therapeutics, McGill University , Montreal, QC , Canada
| | - Issan Zhang
- Department of Pharmacology and Therapeutics, McGill University , Montreal, QC , Canada
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