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Song Y, Liao Y, Liu T, Chen Y, Wang F, Zhou Z, Zhang W, Li J. Microglial repopulation restricts ocular inflammation and choroidal neovascularization in mice. Front Immunol 2024; 15:1366841. [PMID: 38711521 PMCID: PMC11070532 DOI: 10.3389/fimmu.2024.1366841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/04/2024] [Indexed: 05/08/2024] Open
Abstract
Introduction Age-related macular degeneration (AMD) is a prevalent, chronic and progressive retinal degenerative disease characterized by an inflammatory response mediated by activated microglia accumulating in the retina. In this study, we demonstrate the therapeutically effects and the underlying mechanisms of microglial repopulation in the laser-induced choroidal neovascularization (CNV) model of exudative AMD. Methods The CSF1R inhibitor PLX3397 was used to establish a treatment paradigm for microglial repopulation in the retina. Neovascular leakage and neovascular area were examined by fundus fluorescein angiography (FFA) and immunostaining of whole-mount RPE-choroid-sclera complexes in CNV mice receiving PLX3397. Altered cellular senescence was measured by beta-galactosidase (SA-β-gal) activity and p16INK4a expression. The effect and mechanisms of repopulated microglia on leukocyte infiltration and the inflammatory response in CNV lesions were analyzed. Results We showed that ten days of the CSF1R inhibitor PLX3397 treatment followed by 11 days of drug withdrawal was sufficient to stimulate rapid repopulation of the retina with new microglia. Microglial repopulation attenuated pathological choroid neovascularization and dampened cellular senescence in CNV lesions. Repopulating microglia exhibited lower levels of activation markers, enhanced phagocytic function and produced fewer cytokines involved in the immune response, thereby ameliorating leukocyte infiltration and attenuating the inflammatory response in CNV lesions. Discussion The microglial repopulation described herein are therefore a promising strategy for restricting inflammation and choroidal neovascularization, which are important players in the pathophysiology of AMD.
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Affiliation(s)
- Yinting Song
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Yuefeng Liao
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Tong Liu
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Yanxian Chen
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
- Experimental Ophthalmology, School of Optometry, The Hong Kong Polytechnic University, HongKong, Hong Kong SAR, China
| | - Fei Wang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Zixia Zhou
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Weili Zhang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Jinying Li
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
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Bobotis BC, Halvorson T, Carrier M, Tremblay MÈ. Established and emerging techniques for the study of microglia: visualization, depletion, and fate mapping. Front Cell Neurosci 2024; 18:1317125. [PMID: 38425429 PMCID: PMC10902073 DOI: 10.3389/fncel.2024.1317125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/15/2024] [Indexed: 03/02/2024] Open
Abstract
The central nervous system (CNS) is an essential hub for neuronal communication. As a major component of the CNS, glial cells are vital in the maintenance and regulation of neuronal network dynamics. Research on microglia, the resident innate immune cells of the CNS, has advanced considerably in recent years, and our understanding of their diverse functions continues to grow. Microglia play critical roles in the formation and regulation of neuronal synapses, myelination, responses to injury, neurogenesis, inflammation, and many other physiological processes. In parallel with advances in microglial biology, cutting-edge techniques for the characterization of microglial properties have emerged with increasing depth and precision. Labeling tools and reporter models are important for the study of microglial morphology, ultrastructure, and dynamics, but also for microglial isolation, which is required to glean key phenotypic information through single-cell transcriptomics and other emerging approaches. Strategies for selective microglial depletion and modulation can provide novel insights into microglia-targeted treatment strategies in models of neuropsychiatric and neurodegenerative conditions, cancer, and autoimmunity. Finally, fate mapping has emerged as an important tool to answer fundamental questions about microglial biology, including their origin, migration, and proliferation throughout the lifetime of an organism. This review aims to provide a comprehensive discussion of these established and emerging techniques, with applications to the study of microglia in development, homeostasis, and CNS pathologies.
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Affiliation(s)
- Bianca Caroline Bobotis
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Centre for Advanced Materials and Related Technology, Victoria, BC, Canada
| | - Torin Halvorson
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
- British Columbia Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Micaël Carrier
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Psychiatrie et de Neurosciences, Faculté de Médecine, Université Laval, Québec City, QC, Canada
- Axe neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Centre for Advanced Materials and Related Technology, Victoria, BC, Canada
- Axe neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
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Xu Y, Gao W, Sun Y, Wu M. New insight on microglia activation in neurodegenerative diseases and therapeutics. Front Neurosci 2023; 17:1308345. [PMID: 38188026 PMCID: PMC10770846 DOI: 10.3389/fnins.2023.1308345] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Microglia are immune cells within the central nervous system (CNS) closely linked to brain health and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In response to changes in the surrounding environment, microglia activate and change their state and function. Several factors, example for circadian rhythm disruption and the development of neurodegenerative diseases, influence microglia activation. In this review, we explore microglia's function and the associated neural mechanisms. We elucidate that circadian rhythms are essential factors influencing microglia activation and function. Circadian rhythm disruption affects microglia activation and, consequently, neurodegenerative diseases. In addition, we found that abnormal microglia activation is a common feature of neurodegenerative diseases and an essential factor of disease development. Here we highlight the importance of microglia activation in neurodegenerative diseases. Targeting microglia for neurodegenerative disease treatment is a promising direction. We introduce the progress of methods targeting microglia for the treatment of neurodegenerative diseases and summarize the progress of drugs developed with microglia as targets, hoping to provide new ideas for treating neurodegenerative diseases.
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Affiliation(s)
- Yucong Xu
- Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Wei Gao
- Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Yingnan Sun
- Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Minghua Wu
- Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health, The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
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Ai Y, Kong Y, Zou Z, Chen L, Liang G. Long non-coding RNA MIR17HG impedes FOSL2-mediated transcription activation of HIC1 to maintain a pro-inflammatory phenotype of microglia during intracerebral haemorrhage. Eur J Neurosci 2023; 58:4107-4122. [PMID: 37846812 DOI: 10.1111/ejn.16163] [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: 05/12/2023] [Revised: 09/05/2023] [Accepted: 09/19/2023] [Indexed: 10/18/2023]
Abstract
Activation and polarization of microglia play decisive roles in the progression of intracerebral haemorrhage (ICH), and lactate exposure correlates with microglia polarization. This study explores molecules influencing lactate production and microglia phenotype alteration following ICH. A murine model of ICH was induced by intracerebral injection of collagenase. The mice experienced autonomous neurological function recovery, haematoma resolution and rapid lactate production, along with a gradual increase in angiogenesis activity, neuronal recovery and an M1-to-M2 phenotype change of microglia. Galloflavin, a lactate dehydrogenase antagonist, suppressed this phenotype change and the functional recovery in mice. FOS like 2 (FOSL2) was significantly upregulated in the brain tissues from day 7 post-ICH. Overexpression of FOSL2 induced an M1-to-M2 phenotype shift in microglia and accelerated lactate production in vivo and in haemoglobin-treated microglia in vitro. Long non-coding RNA MIR17HG impeded FOSL2-mediated transcription activation of hypermethylated in cancer 1 (HIC1). MIR17HG overexpression induced pro-inflammatory activation of microglia in mice, which was blocked by further HIC1 overexpression. Overall, this study demonstrates that MIR17HG maintains a pro-inflammatory phenotype of microglia during ICH progression by negating FOSL2-mediated transcription activation of HIC1. Specific inhibition of MIR17HG or upregulation of FOSL2 or HIC1 may favour inflammation inhibition and haematoma resolution in ICH.
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Affiliation(s)
- Yunzheng Ai
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Ying Kong
- Department of Neurology, General Hospital of Northern Theater Command, Shenyang, China
| | - Zheng Zou
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Ligang Chen
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Guobiao Liang
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, China
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Crews FT, Coleman LG, Macht VA, Vetreno RP. Targeting Persistent Changes in Neuroimmune and Epigenetic Signaling in Adolescent Drinking to Treat Alcohol Use Disorder in Adulthood. Pharmacol Rev 2023; 75:380-396. [PMID: 36781218 PMCID: PMC9969522 DOI: 10.1124/pharmrev.122.000710] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/24/2022] [Accepted: 10/28/2022] [Indexed: 12/15/2022] Open
Abstract
Studies universally find early age of drinking onset is linked to lifelong risks of alcohol problems and alcohol use disorder (AUD). Assessment of the lasting effect of drinking during adolescent development in humans is confounded by the diversity of environmental and genetic factors that affect adolescent development, including emerging personality disorders and progressive increases in drinking trajectories into adulthood. Preclinical studies using an adolescent intermittent ethanol (AIE) exposure rat model of underage binge drinking avoid the human confounds and support lifelong changes that increase risks. AIE increases adult alcohol drinking, risky decision-making, reward-seeking, and anxiety as well as reductions in executive function that all increase risks for the development of an AUD. AIE causes persistent increases in brain neuroimmune signaling high-mobility group box 1 (HMGB1), Toll-like receptor, receptor for advanced glycation end products, and innate immune genes that are also found to be increased in human AUD brain. HMGB1 is released from cells by ethanol, both free and within extracellular vesicles, that act on neurons and glia, shifting transcription and cellular phenotype. AIE-induced decreases in adult hippocampal neurogenesis and loss of basal forebrain cholinergic neurons are reviewed as examples of persistent AIE-induced pathology. Both are prevented and reversed by anti-inflammatory and epigenetic drugs. Findings suggest AIE-increased HMGB1 signaling induces the RE-1 silencing transcript blunting cholinergic gene expression, shifting neuronal phenotype. Inhibition of HMGB1 neuroimmune signaling, histone methylation enzymes, and galantamine, the cholinesterase inhibitor, both prevent and reverse AIE pathology. These findings provide new targets that may reverse AUD neuropathology as well as other brain diseases linked to neuroimmune signaling. SIGNIFICANCE STATEMENT: Adolescent underage binge drinking studies find that earlier adolescent drinking is associated with lifelong alcohol problems including high levels of lifetime alcohol use disorder (AUD). Preclinical studies find the underage binge drinking adolescent intermittent ethanol (AIE) model causes lasting changes in adults that increase risks of developing adult alcohol problems. Loss of hippocampal neurogenesis and loss of basal forebrain cholinergic neurons provide examples of how AIE-induced epigenetic and neuroimmune signaling provide novel therapeutic targets for adult AUD.
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Affiliation(s)
- Fulton T Crews
- Bowles Center for Alcohol Studies and Departments of Pharmacology and Psychiatry, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Leon G Coleman
- Bowles Center for Alcohol Studies and Departments of Pharmacology and Psychiatry, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Victoria A Macht
- Bowles Center for Alcohol Studies and Departments of Pharmacology and Psychiatry, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Ryan P Vetreno
- Bowles Center for Alcohol Studies and Departments of Pharmacology and Psychiatry, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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Li H, Zhou B, Liao P, Liao D, Yang L, Wang J, Liu J, Jiang R, Chen L. Prolonged exposure of neonatal mice to sevoflurane leads to hyper-ramification in microglia, reduced contacts between microglia and synapses, and defects in adult behavior. Front Neurol 2023; 14:1142739. [PMID: 37025197 PMCID: PMC10072331 DOI: 10.3389/fneur.2023.1142739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/24/2023] [Indexed: 04/08/2023] Open
Abstract
Background Prolonged exposure to general anesthetics during development is known to cause neurobehavioral abnormalities, but the cellular and molecular mechanisms involved are unclear. Microglia are the resident immune cells in the central nervous system and play essential roles in normal brain development. Materials and methods In the study, postnatal day 7 (P7) C57BL/6 mice were randomly assigned to two groups. In the sevoflurane (SEVO), mice were exposed to 2.5% sevoflurane for 4 h. In the control group, mice were exposed to carrier gas (30% O2/70% N2) for 4 h. Fixed brain slices from P14 to P21 mice were immunolabeled for ionized calcium-binding adapter molecule 1 (IBA-1) to visualize microglia. The morphological analysis of microglia in the somatosensory cortex was performed using ImageJ and Imaris software. Serial block face scanning electron microscopy (SBF-SEM) was performed to assess the ultrastructure of the microglia and the contacts between microglia and synapse in P14 and P21 mice. The confocal imaging of brain slices was performed to assess microglia surveillance in resting and activated states in P14 and P21 mice. Behavioral tests were used to assess the effect of microglia depletion and repopulation on neurobehavioral abnormalities caused by sevoflurane exposure. Results The prolonged exposure of neonatal mice to sevoflurane induced microglia hyper-ramification with an increase in total branch length, arborization area, and branch complexity 14 days after exposure. Prolonged neonatal sevoflurane exposure reduced contacts between microglia and synapses, without affecting the surveillance of microglia in the resting state or responding to laser-induced focal brain injury. These neonatal changes in microglia were associated with anxiety-like behaviors in adult mice. Furthermore, microglial depletion before sevoflurane exposure and subsequent repopulation in the neonatal brain mitigated anxiety-like behaviors caused by sevoflurane exposure. Conclusion Our experiments indicate that general anesthetics may harm the developing brain, and microglia may be an essential target of general anesthetic-related developmental neurotoxicity.
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Affiliation(s)
- Hong Li
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Bin Zhou
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Daqing Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Linghui Yang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Wang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Ruotian Jiang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Ruotian Jiang,
| | - Lingmin Chen
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Lingmin Chen,
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