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Yan L, Chen C, Wang L, Hong H, Wu C, Huang J, Jiang J, Chen J, Xu G, Cui Z. Analysis of gene expression in microglial apoptotic cell clearance following spinal cord injury based on machine learning algorithms. Exp Ther Med 2024; 28:292. [PMID: 38827468 PMCID: PMC11140288 DOI: 10.3892/etm.2024.12581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 04/17/2024] [Indexed: 06/04/2024] Open
Abstract
Spinal cord injury (SCI) is a severe neurological complication following spinal fracture, which has long posed a challenge for clinicians. Microglia play a dual role in the pathophysiological process after SCI, both beneficial and detrimental. The underlying mechanisms of microglial actions following SCI require further exploration. The present study combined three different machine learning algorithms, namely weighted gene co-expression network analysis, random forest analysis and least absolute shrinkage and selection operator analysis, to screen for differentially expressed genes in the GSE96055 microglia dataset after SCI. It then used protein-protein interaction networks and gene set enrichment analysis with single genes to investigate the key genes and signaling pathways involved in microglial function following SCI. The results indicated that microglia not only participate in neuroinflammation but also serve a significant role in the clearance mechanism of apoptotic cells following SCI. Notably, bioinformatics analysis and lipopolysaccharide + UNC569 (a MerTK-specific inhibitor) stimulation of BV2 cell experiments showed that the expression levels of Anxa2, Myo1e and Spp1 in microglia were significantly upregulated following SCI, thus potentially involved in regulating the clearance mechanism of apoptotic cells. The present study suggested that Anxa2, Myo1e and Spp1 may serve as potential targets for the future treatment of SCI and provided a theoretical basis for the development of new methods and drugs for treating SCI.
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Affiliation(s)
- Lei Yan
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Chu Chen
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Lingling Wang
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Hongxiang Hong
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Chunshuai Wu
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Jiayi Huang
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Jiawei Jiang
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Jiajia Chen
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Guanhua Xu
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
| | - Zhiming Cui
- The First People's Hospital of Nantong, The Second Affiliated Hospital of Nantong University, Research Institute for Spine and Spinal Cord Disease of Nantong University, Nantong, Jiangsu 226019, P.R. China
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Balena T, Lillis K, Rahmati N, Bahari F, Dzhala V, Berdichevsky E, Staley K. A Dynamic Balance between Neuronal Death and Clearance in an in Vitro Model of Acute Brain Injury. J Neurosci 2023; 43:6084-6107. [PMID: 37527922 PMCID: PMC10451151 DOI: 10.1523/jneurosci.0436-23.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/15/2023] [Accepted: 07/20/2023] [Indexed: 08/03/2023] Open
Abstract
In in vitro models of acute brain injury, neuronal death may overwhelm the capacity for microglial phagocytosis, creating a queue of dying neurons awaiting clearance. Neurons undergoing programmed cell death are in this queue, and are the most visible and frequently quantified measure of neuronal death after injury. However, the size of this queue should be equally sensitive to changes in neuronal death and the rate of phagocytosis. Using rodent organotypic hippocampal slice cultures as a model of acute perinatal brain injury, serial imaging demonstrated that the capacity for microglial phagocytosis of dying neurons was overwhelmed for 2 weeks. Altering phagocytosis rates (e.g., by changing the number of microglia) dramatically changed the number of visibly dying neurons. Similar effects were generated when the visibility of dying neurons was altered by changing the membrane permeability for stains that label dying neurons. Canonically neuroprotective interventions, such as seizure blockade, and neurotoxic maneuvers, such as perinatal ethanol exposure, were mediated by effects on microglial activity and the membrane permeability of neurons undergoing programmed cell death. These canonically neuroprotective and neurotoxic interventions had either no or opposing effects on healthy surviving neurons identified by the ongoing expression of transgenic fluorescent proteins.SIGNIFICANCE STATEMENT In in vitro models of acute brain injury, microglial phagocytosis is overwhelmed by the number of dying cells. Under these conditions, the assumptions on which assays for neuroprotective and neurotoxic effects are based are no longer valid. Thus, longitudinal assays of healthy cells, such as serial assessment of the fluorescence emission of transgenically expressed proteins, provide more accurate estimates of cell death than do single-time point anatomic or biochemical assays of the number of dying neurons. More accurate estimates of death rates in vitro will increase the translatability of preclinical studies of neuroprotection and neurotoxicity.
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Affiliation(s)
- Trevor Balena
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Kyle Lillis
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Negah Rahmati
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Fatemeh Bahari
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Volodymyr Dzhala
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Eugene Berdichevsky
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
| | - Kevin Staley
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
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Balena T, Lillis K, Rahmati N, Bahari F, Dzhala V, Berdichevsky E, Staley K. A dynamic balance between neuronal death and clearance after acute brain injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528332. [PMID: 36824708 PMCID: PMC9948967 DOI: 10.1101/2023.02.14.528332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
After acute brain injury, neuronal apoptosis may overwhelm the capacity for microglial phagocytosis, creating a queue of dying neurons awaiting clearance. The size of this queue should be equally sensitive to changes in neuronal death and the rate of phagocytosis. Using rodent organotypic hippocampal slice cultures as a model of acute perinatal brain injury, serial imaging demonstrated that the capacity for microglial phagocytosis of dying neurons was overwhelmed for two weeks. Altering phagocytosis rates, e.g. by changing the number of microglia, dramatically changed the number of visibly dying neurons. Similar effects were generated when the visibility of dying neurons was altered by changing the membrane permeability for vital stains. Canonically neuroprotective interventions such as seizure blockade and neurotoxic maneuvers such as perinatal ethanol exposure were mediated by effects on microglial activity and the membrane permeability of apoptotic neurons, and had either no or opposing effects on healthy surviving neurons. Significance After acute brain injury, microglial phagocytosis is overwhelmed by the number of dying cells. Under these conditions, the assumptions on which assays for neuroprotective and neurotoxic effects are based are no longer valid. Thus longitudinal assays of healthy cells, such as assessment of the fluorescence emission of transgenically-expressed proteins, provide more accurate estimates of cell death than do single-time-point anatomical or biochemical assays. More accurate estimates of death rates will increase the translatability of preclinical studies of neuroprotection and neurotoxicity.
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Fu XQ, Lin ZL, Li LY, Wang Q, Deng L, Lin Z, Lin JJ, Wang XY, Shen TY, Zheng YH, Lin W, Li PJ. Chlorogenic acid alleviates hypoxic-ischemic brain injury in neonatal mice. Neural Regen Res 2023; 18:568-576. [DOI: 10.4103/1673-5374.350203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Monsorno K, Buckinx A, Paolicelli RC. Microglial metabolic flexibility: emerging roles for lactate. Trends Endocrinol Metab 2022; 33:186-195. [PMID: 34996673 DOI: 10.1016/j.tem.2021.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 12/28/2022]
Abstract
Microglia, the resident macrophages of the central nervous system (CNS), play important functions in the healthy and diseased brain. In the emerging field of immunometabolism, progress has been made in understanding how cellular metabolism can orchestrate the key responses of tissue macrophages, such as phagocytosis and inflammation. However, very little is known about the metabolic control of microglia. Lactate, now recognized as a crucial metabolite and a central substrate in metabolic flexibility, is emerging not only as a novel bioenergetic fuel for microglial metabolism but also as a potential modulator of cellular function. Parallels with macrophages will help in understanding how microglial lactate metabolism is implicated in brain physiology and pathology, and how it could be targeted for therapeutic purposes.
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Affiliation(s)
- Katia Monsorno
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - An Buckinx
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Rosa C Paolicelli
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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Taheri F, Taghizadeh E, Navashenaq JG, Rezaee M, Gheibihayat SM. The role of efferocytosis in neuro-degenerative diseases. Neurol Sci 2022; 43:1593-1603. [PMID: 35059903 DOI: 10.1007/s10072-021-05835-6] [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: 10/23/2021] [Accepted: 12/11/2021] [Indexed: 02/06/2023]
Abstract
Efferocytosis has a critical role in maintaining tissues and organs' homeostasis by removing apoptotic cells. It is essential for human health, and disturbances in efferocytosis may result indifferent illnesses. In case of inadequate clearance of the dead cells, the content in the cells would be released. In fact, it induces some damages to the tissue and leads to the prolonged inflammation, so unsuitable phagocytosis of the apoptotic cells is involved in occurrence as well as expansion of numerous human chronic inflammatory diseases. Studies have shown age dependence of the neuro-degenerative diseases, which are largely due to the neuro-inflammation and the loss of neurons and thus cause the brain's functional disorders. Efferocytosis is coupled to anti-inflammatory responses that contribute to the elimination of the dying neurons in neuro-degenerative diseases, so its disruption may make a risk factor in numerous human chronic inflammatory diseases such as multiple sclerosis, Alzheimer's disease, glioblastoma, and Rett syndrome. This study is a review of the efferocytosis molecular pathways and their role in neuro-degenerative diseases in order to discover a new treatment option to cure patients.
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Affiliation(s)
- Forough Taheri
- Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Eskandar Taghizadeh
- Department of Medical Genetic, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Mehdi Rezaee
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran.,Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Seyed Mohammad Gheibihayat
- Department of Medical Biotechnology, School of Medicine, Shahid Sadoughi University of Medical Sciences, P.O. Box: 8915173143, Yazd, Iran.
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Zhao J, Zhang W, Wu T, Wang H, Mao J, Liu J, Zhou Z, Lin X, Yan H, Wang Q. Efferocytosis in the Central Nervous System. Front Cell Dev Biol 2021; 9:773344. [PMID: 34926460 PMCID: PMC8678611 DOI: 10.3389/fcell.2021.773344] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022] Open
Abstract
The effective clearance of apoptotic cells is essential for maintaining central nervous system (CNS) homeostasis and restoring homeostasis after injury. In most cases of physiological apoptotic cell death, efferocytosis prevents inflammation and other pathological conditions. When apoptotic cells are not effectively cleared, destruction of the integrity of the apoptotic cell membrane integrity, leakage of intracellular contents, and secondary necrosis may occur. Efferocytosis is the mechanism by which efferocytes quickly remove apoptotic cells from tissues before they undergo secondary necrosis. Cells with efferocytosis functions, mainly microglia, help to eliminate apoptotic cells from the CNS. Here, we discuss the impacts of efferocytosis on homeostasis, the mechanism of efferocytosis, the associations of efferocytosis failure and CNS diseases, and the current clinical applications of efferocytosis. We also identify efferocytosis as a novel potential target for exploring the causes and treatments of CNS diseases.
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Affiliation(s)
- Jiayi Zhao
- Department of Anesthesia, Zhejiang Hospital, Hangzhou, China
| | - Weiqi Zhang
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Tingting Wu
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Hongyi Wang
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jialiang Mao
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jian Liu
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ziheng Zhou
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xianfeng Lin
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Huige Yan
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qingqing Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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Microglia as the Critical Regulators of Neuroprotection and Functional Recovery in Cerebral Ischemia. Cell Mol Neurobiol 2021; 42:2505-2525. [PMID: 34460037 DOI: 10.1007/s10571-021-01145-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022]
Abstract
Microglial activation is considered as the critical pathogenic event in diverse central nervous system disorders including cerebral ischemia. Proinflammatory responses of activated microglia have been well reported in the ischemic brain and neuroinflammatory responses of activated microglia have been believed to be the potential therapeutic strategy. However, despite having proinflammatory roles, microglia can have significant anti-inflammatory roles and they are associated with the production of growth factors which are responsible for neuroprotection and recovery after ischemic injury. Microglia can directly promote neuroprotection by preventing ischemic infarct expansion and promoting functional outcomes. Indirectly, microglia are involved in promoting anti-inflammatory responses, neurogenesis, and angiogenesis in the ischemic brain which are crucial pathophysiological events for ischemic recovery. In fact, anti-inflammatory cytokines and growth factors produced by microglia can promote neuroprotection and attenuate neurobehavioral deficits. In addition, microglia regulate phagocytosis, axonal regeneration, blood-brain barrier protection, white matter integrity, and synaptic remodeling, which are essential for ischemic recovery. Microglia can also regulate crosstalk with neurons and other cell types to promote neuroprotection and ischemic recovery. This review mainly focuses on the roles of microglia in neuroprotection and recovery following ischemic injury. Furthermore, this review also sheds the light on the therapeutic potential of microglia in stroke patients.
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Alexaki VI. The Impact of Obesity on Microglial Function: Immune, Metabolic and Endocrine Perspectives. Cells 2021; 10:cells10071584. [PMID: 34201844 PMCID: PMC8307603 DOI: 10.3390/cells10071584] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Increased life expectancy in combination with modern life style and high prevalence of obesity are important risk factors for development of neurodegenerative diseases. Neuroinflammation is a feature of neurodegenerative diseases, and microglia, the innate immune cells of the brain, are central players in it. The present review discusses the effects of obesity, chronic peripheral inflammation and obesity-associated metabolic and endocrine perturbations, including insulin resistance, dyslipidemia and increased glucocorticoid levels, on microglial function.
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Affiliation(s)
- Vasileia Ismini Alexaki
- Institute for Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
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