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Peshoff MM, Gupta P, Oberai S, Trivedi R, Katayama H, Chakrapani P, Dang M, Migliozzi S, Gumin J, Kadri DB, Lin JK, Milam NK, Maynard ME, Vaillant BD, Parker-Kerrigan B, Lang FF, Huse JT, Iavarone A, Wang L, Clise-Dwyer K, Bhat KP. Triggering receptor expressed on myeloid cells 2 (TREM2) regulates phagocytosis in glioblastoma. Neuro Oncol 2024; 26:826-839. [PMID: 38237157 PMCID: PMC11066944 DOI: 10.1093/neuonc/noad257] [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: 04/03/2023] [Indexed: 01/30/2024] Open
Abstract
BACKGROUND Glioblastomas (GBMs) are central nervous system tumors that resist standard-of-care interventions and even immune checkpoint blockade. Myeloid cells in the tumor microenvironment can contribute to GBM progression; therefore, emerging immunotherapeutic approaches include reprogramming these cells to achieve desirable antitumor activity. Triggering receptor expressed on myeloid cells 2 (TREM2) is a myeloid signaling regulator that has been implicated in a variety of cancers and neurological diseases with contrasting functions, but its role in GBM immunopathology and progression is still under investigation. METHODS Our reverse translational investigations leveraged single-cell RNA sequencing and cytometry of human gliomas to characterize TREM2 expression across myeloid subpopulations. Using 2 distinct murine glioma models, we examined the role of Trem2 on tumor progression and immune modulation of myeloid cells. Furthermore, we designed a method of tracking phagocytosis of glioma cells in vivo and employed in vitro assays to mechanistically understand the influence of TREM2 signaling on tumor uptake. RESULTS We discovered that TREM2 expression does not correlate with immunosuppressive pathways, but rather showed strong a positive association with the canonical phagocytosis markers lysozyme (LYZ) and macrophage scavenger receptor (CD163) in gliomas. While Trem2 deficiency was found to be dispensable for gliomagenesis, Trem2+ myeloid cells display enhanced tumor uptake compared to Trem2- cells. Mechanistically, we demonstrate that TREM2 mediates phagocytosis via Syk signaling. CONCLUSIONS These results indicate that TREM2 is not associated with immunosuppression in gliomas. Instead, TREM2 is an important regulator of phagocytosis that may be exploited as a potential therapeutic strategy for brain tumors.
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Affiliation(s)
- Mekenzie M Peshoff
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Translational Molecular Pathology, The University of Texas, MD Anderson Cancer Center, UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Pravesh Gupta
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Shivangi Oberai
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Rakesh Trivedi
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Hiroshi Katayama
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Prashanth Chakrapani
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Minghao Dang
- Department of Genomic Medicine, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Simona Migliozzi
- Department of Neurological Surgery, Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Joy Gumin
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Divya B Kadri
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jessica K Lin
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Nancy K Milam
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Mark E Maynard
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, USA
| | - Brian D Vaillant
- Departments of Translational Molecular Pathology, Dell Medical School, University of Texas at Austin, Austin, Texas, USA
| | - Brittany Parker-Kerrigan
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Frederick F Lang
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jason T Huse
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Translational Molecular Pathology, The University of Texas, MD Anderson Cancer Center, UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Antonio Iavarone
- Department of Neurological Surgery, Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Linghua Wang
- Department of Genomic Medicine, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Karen Clise-Dwyer
- Department of Hematopoietic Biology & Malignancy, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Krishna P Bhat
- Department of Translational Molecular Pathology, Neurosurgery at the University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Translational Molecular Pathology, The University of Texas, MD Anderson Cancer Center, UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
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Xie C, Zhang Q, Ye X, Wu W, Cheng X, Ye X, Ruan J, Pan X. Periodontitis-induced neuroinflammation impacts dendritic spine immaturity and cognitive impairment. Oral Dis 2024; 30:2558-2569. [PMID: 37455416 DOI: 10.1111/odi.14674] [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: 11/12/2022] [Revised: 06/03/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023]
Abstract
OBJECTIVE This study investigated the spinal changes in ligature-induced periodontitis and the role of periodontitis in cognitive impairment. METHODS Twenty mice were randomized into the control and chronic periodontitis (CP) groups, with the latter receiving ligature-induced periodontitis. Cognitive performance was assessed by fear conditioning test. Periodontal inflammation and alveolar bone resorption were evaluated by micro-computed tomography and histopathology. The hippocampal microglial activation was evaluated by immunohistochemistry (IHC). The expressions of hippocampal cytokines (TNF-α, iNOS, IL-1β, IL-4, IL-10, and TREM2) were measured by reverse transcription-polymerase chain reaction. The morphology and density of the dendritic spines were determined by Golgi-Cox staining. RESULTS The CP mice reported significant inflammatory cell infiltration and alveolar bone resorption, with marked increases in cytokine levels (TNF-α, iNOS, IL-1β, and TREM2) in the brain. Moreover, the CP mice showed significantly reduced freezing to the conditioned stimulus in the cued and contextual tests, indicating impaired memory. Further analyses revealed, in the hippocampus of the CP mice, enhanced microglial activation, decreased dendritic spine density, and increased proportion of thin dendritic spines. CONCLUSIONS Periodontitis-induced neuroinflammation may impair the cognitive function by activating hippocampal microglia and inducing dendritic spine immaturity.
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Affiliation(s)
- Changfu Xie
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Qiuyang Zhang
- The Third Clinical Medical College, Fujian Medical University, Fuzhou, China
- Fuzhou Second Hospital, Fuzhou, China
| | - Xinyi Ye
- Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Weiliang Wu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Xiaojuan Cheng
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Xiaoan Ye
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Jianyong Ruan
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Xiaodong Pan
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
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3
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Maeda C, Tsuruta F. Molecular Basis of Neuronal and Microglial States in the Aging Brain and Impact on Cerebral Blood Vessels. Int J Mol Sci 2024; 25:4443. [PMID: 38674028 PMCID: PMC11049950 DOI: 10.3390/ijms25084443] [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: 03/13/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Brain aging causes a wide variety of changes at the molecular and cellular levels, leading to the decline of cognitive functions and increased vulnerability to neurodegenerative disorders. The research aimed at understanding the aging of the brain has made much progress in recent decades. Technological innovations such as single-cell RNA-sequencing (scRNA-seq), proteomic analyses, and spatial transcriptomic analyses have facilitated the research on the dynamic changes occurring within neurons, glia, and other cells along with their impacts on intercellular communication during aging. In this review, we introduce recent trends of how neurons and glia change during aging and discuss the impact on the brain microenvironment such as the blood-brain barrier (BBB).
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Affiliation(s)
- Chihiro Maeda
- Master’s and Doctoral Program in Biology, Degree Programs in Life and Earth Sciences, Graduate School of Science and Technology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan;
| | - Fuminori Tsuruta
- Master’s and Doctoral Programs in Biology, Institute of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
- Ph.D. Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
- Ph.D. Program in Humanics, School of Integrative and Global Majors, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
- Master’s and Doctoral Program in Neuroscience, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Ibaraki, Japan
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Wißfeld J, Abou Assale T, Cuevas-Rios G, Liao H, Neumann H. Therapeutic potential to target sialylation and SIGLECs in neurodegenerative and psychiatric diseases. Front Neurol 2024; 15:1330874. [PMID: 38529039 PMCID: PMC10961342 DOI: 10.3389/fneur.2024.1330874] [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: 10/31/2023] [Accepted: 02/21/2024] [Indexed: 03/27/2024] Open
Abstract
Sialic acids, commonly found as the terminal carbohydrate on the glycocalyx of mammalian cells, are pivotal checkpoint inhibitors of the innate immune system, particularly within the central nervous system (CNS). Sialic acid-binding immunoglobulin-like lectins (SIGLECs) expressed on microglia are key players in maintaining microglial homeostasis by recognizing intact sialylation. The finely balanced sialic acid-SIGLEC system ensures the prevention of excessive and detrimental immune responses in the CNS. However, loss of sialylation and SIGLEC receptor dysfunctions contribute to several chronic CNS diseases. Genetic variants of SIGLEC3/CD33, SIGLEC11, and SIGLEC14 have been associated with neurodegenerative diseases such as Alzheimer's disease, while sialyltransferase ST8SIA2 and SIGLEC4/MAG have been linked to psychiatric diseases such as schizophrenia, bipolar disorders, and autism spectrum disorders. Consequently, immune-modulatory functions of polysialic acids and SIGLEC binding antibodies have been exploited experimentally in animal models of Alzheimer's disease and inflammation-induced CNS tissue damage, including retinal damage. While the potential of these therapeutic approaches is evident, only a few therapies to target either sialylation or SIGLEC receptors have been tested in patient clinical trials. Here, we provide an overview of the critical role played by the sialic acid-SIGLEC axis in shaping microglial activation and function within the context of neurodegeneration and synaptopathies and discuss the current landscape of therapies that target sialylation or SIGLECs.
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Affiliation(s)
- Jannis Wißfeld
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Tawfik Abou Assale
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital Bonn, University of Bonn, Bonn, Germany
| | - German Cuevas-Rios
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Huan Liao
- Florey Institute of Neuroscience and Mental Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Harald Neumann
- Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital Bonn, University of Bonn, Bonn, Germany
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5
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Brown GC. Cell death by phagocytosis. Nat Rev Immunol 2024; 24:91-102. [PMID: 37604896 DOI: 10.1038/s41577-023-00921-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2023] [Indexed: 08/23/2023]
Abstract
Cells can die as a consequence of being phagocytosed by other cells - a form of cell death that has been called phagotrophy, cell cannibalism, programmed cell removal and primary phagocytosis. However, these are all different manifestations of cell death by phagocytosis (termed 'phagoptosis' for short). The engulfed cells die as a result of cytotoxic oxidants, peptides and degradative enzymes within acidic phagolysosomes. Cell death by phagocytosis was discovered by Metchnikov in the 1880s, but was neglected until recently. It is now known to contribute to developmental cell death in nematodes, Drosophila and mammals, and is central to innate and adaptive immunity against pathogens. Cell death by phagocytosis mediates physiological turnover of erythrocytes and other leucocytes, making it the most abundant form of cell death in the mammalian body. Immunity against cancer is also partly mediated by macrophage phagocytosis of cancer cells, but cancer cells can also phagocytose host cells and other cancer cells in order to survive. Recent evidence indicates neurodegeneration and other neuropathologies can be mediated by microglial phagocytosis of stressed neurons. Thus, despite cell death by phagocytosis being poorly recognized, it is one of the oldest, commonest and most important forms of cell death.
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Affiliation(s)
- Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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6
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Wen L, Bi D, Shen Y. Complement-mediated synapse loss in Alzheimer's disease: mechanisms and involvement of risk factors. Trends Neurosci 2024; 47:135-149. [PMID: 38129195 DOI: 10.1016/j.tins.2023.11.010] [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: 06/20/2023] [Revised: 10/25/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
The complement system is increasingly recognized as a key player in the synapse loss and cognitive impairments observed in Alzheimer's disease (AD). In particular, the process of complement-dependent synaptic pruning through phagocytosis is over-activated in AD brains, driving detrimental excessive synapse elimination and contributing to synapse loss, which is the strongest neurobiological correlate of cognitive impairments in AD. Herein we review recent advances in characterizing complement-mediated synapse loss in AD, summarize the underlying mechanisms, and discuss the possible involvement of AD risk factors such as aging and various risk genes. We conclude with an overview of key questions that remain to be addressed.
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Affiliation(s)
- Lang Wen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Danlei Bi
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China; Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Yong Shen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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7
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Lei S, Hu M, Wei Z. Single-cell sequencing reveals an important role of SPP1 and microglial activation in age-related macular degeneration. Front Cell Neurosci 2024; 17:1322451. [PMID: 38259505 PMCID: PMC10801008 DOI: 10.3389/fncel.2023.1322451] [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: 10/20/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
Purpose To investigate the role of senescence-related cytokines (SRCs) in the pathophysiology of age-related macular degeneration (AMD). Design The whole study is based on single-cell and bulk tissue transcriptomic analysis of the human neuroretinas with or without AMD. The transcriptomic data of human neuroretinas was obtained from Gene-Expression Omnibus (GEO) database. Methods For single-cell transcriptomic analysis, the gene expression matrix goes through quality control (QC) filtering, being normalized, scaled and integrated for downstream analysis. The further analyses were performed using Seurat R package and CellChat R package. After cell type annotation, the expression of phenotype and functional markers of microglia was investigated and cell-cell communication analysis was performed. For bulk tissue transcriptomic analysis, GSE29801 dataset contains the transcriptomic data of human macular neuroretina (n = 118) from control group and AMD patients. The expression of SPP1 in control and AMD subtypes were compared by Student's t-test. In addition, the AMD macular neuroretina were classified into SPP1-low and SPP1-high groups according to the expression level of SPP1. The differentially expressed genes between these two groups were subsequently identified and the pathway enrichment analysis for these genes was further conducted. Results Secreted phosphoprotein 1, as an SRC, was revealed to be highly expressed in microglia of AMD neuroretina and the SPP1-receptor signaling was highly activated in AMD neuroretina. In addition, SPP1 signaling was associated with the pro-inflammatory phenotype and phagocytic state of microglia. SPP1 expression was elevated in macular neuroretina with late dry and wet AMD and the inflammatory pathways were found to be activated in SPP1-high AMD macular neuroretina. Conclusion Our findings indicated that SPP1 and microglial activation might play an important role in the pathophysiology of AMD. Therefore, SPP1 might serve as a potential therapeutic target for AMD. More in vitro and in vivo studies are required to confirm the results and the therapeutic effect of SPP1-targeting strategy.
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Affiliation(s)
- Shizhen Lei
- Department of Ophthalmology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Mang Hu
- Department of Ophthalmology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Sudwarts A, Thinakaran G. Alzheimer's genes in microglia: a risk worth investigating. Mol Neurodegener 2023; 18:90. [PMID: 37986179 PMCID: PMC10662636 DOI: 10.1186/s13024-023-00679-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
Despite expressing many key risk genes, the role of microglia in late-onset Alzheimer's disease pathophysiology is somewhat ambiguous, with various phenotypes reported to be either harmful or protective. Herein, we review some key findings from clinical and animal model investigations, discussing the role of microglial genetics in mediating perturbations from homeostasis. We note that impairment to protective phenotypes may include prolonged or insufficient microglial activation, resulting in dysregulated metabolomic (notably lipid-related) processes, compounded by age-related inflexibility in dynamic responses. Insufficiencies of mouse genetics and aggressive transgenic modelling imply severe limitations in applying current methodologies for aetiological investigations. Despite the shortcomings, widely used amyloidosis and tauopathy models of the disease have proven invaluable in dissecting microglial functional responses to AD pathophysiology. Some recent advances have brought modelling tools closer to human genetics, increasing the validity of both aetiological and translational endeavours.
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Affiliation(s)
- Ari Sudwarts
- Byrd Alzheimer's Center and Research Institute, University of South Florida, Tampa, FL, 33613, USA.
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
| | - Gopal Thinakaran
- Byrd Alzheimer's Center and Research Institute, University of South Florida, Tampa, FL, 33613, USA.
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
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Liu Y, Yang W, Xue J, Chen J, Liu S, Zhang S, Zhang X, Gu X, Dong Y, Qiu P. Neuroinflammation: The central enabler of postoperative cognitive dysfunction. Biomed Pharmacother 2023; 167:115582. [PMID: 37748409 DOI: 10.1016/j.biopha.2023.115582] [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: 07/25/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 09/27/2023] Open
Abstract
The proportion of advanced age patients undergoing surgical procedures is on the rise owing to advancements in surgical and anesthesia technologies as well as an overall aging population. As a complication of anesthesia and surgery, older patients frequently suffer from postoperative cognitive dysfunction (POCD), which may persist for weeks, months or even longer. POCD is a complex pathological process involving multiple pathogenic factors, and its mechanism is yet unclear. Potential theories include inflammation, deposition of pathogenic proteins, imbalance of neurotransmitters, and chronic stress. The identification, prevention, and treatment of POCD are still in the exploratory stages owing to the absence of standardized diagnostic criteria. Undoubtedly, comprehending the development of POCD remains crucial in overcoming the illness. Neuroinflammation is the leading hypothesis and a crucial component of the pathological network of POCD and may have complex interactions with other mechanisms. In this review, we discuss the possible ways in which surgery and anesthesia cause neuroinflammation and investigate the connection between neuroinflammation and the development of POCD. Understanding these mechanisms may likely ensure that future treatment options of POCD are more effective.
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Affiliation(s)
- Yang Liu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Wei Yang
- Department of Infectious Disease, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Jinqi Xue
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Juntong Chen
- Zhejiang University School of Medicine, Hangzhou 311121, Zhejiang province, China
| | - Shiqing Liu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Shijie Zhang
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Xiaohui Zhang
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Xi Gu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China.
| | - Youjing Dong
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
| | - Peng Qiu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
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Schneider K, Arandjelovic S. Apoptotic cell clearance components in inflammatory arthritis. Immunol Rev 2023; 319:142-150. [PMID: 37507355 PMCID: PMC10615714 DOI: 10.1111/imr.13256] [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: 05/07/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints that affects ~1% of the human population. Joint swelling and bone erosion, hallmarks of RA, contribute to disability and, sometimes, loss of life. Mechanistically, disease is driven by immune dysregulation characterized by circulating autoantibodies, inflammatory mediators, tissue degradative enzymes, and metabolic dysfunction of resident stromal and recruited immune cells. Cell death by apoptosis has been therapeutically explored in animal models of RA due to the comparisons drawn between synovial hyperplasia and paucity of apoptosis in RA with the malignant transformation of cancer cells. Several efforts to induce cell death have shown benefits in reducing the development and/or severity of the disease. Apoptotic cells are cleared by phagocytes in a process known as efferocytosis, which differs from microbial phagocytosis in its "immuno-silent," or anti-inflammatory, nature. Failures in efferocytosis have been linked to autoimmune disease, whereas administration of apoptotic cells in RA models effectively inhibits inflammatory indices, likely though efferocytosis-mediated resolution-promoting mechanisms. However, the nature of signaling pathways elicited and the molecular identity of clearance mediators in RA are understudied. Furthermore, canonical efferocytosis machinery elements also play important non-canonical functions in homeostasis and pathology. Here, we discuss the roles of efferocytosis machinery components in models of RA and discuss their potential involvement in disease pathophysiology.
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Affiliation(s)
- Kevin Schneider
- University of Virginia, Center for Immunity, Inflammation and Regenerative Medicine, Department of Medicine, Charlottesville, VA, USA
| | - Sanja Arandjelovic
- University of Virginia, Center for Immunity, Inflammation and Regenerative Medicine, Department of Medicine, Charlottesville, VA, USA
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11
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Biundo F, Chitu V, Gökhan Ş, Chen E, Oppong-Asare J, Stanley ER. Trem2 Enhances Demyelination in the Csf1r+/- Mouse Model of Leukoencephalopathy. Biomedicines 2023; 11:2094. [PMID: 37626591 PMCID: PMC10452898 DOI: 10.3390/biomedicines11082094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/23/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
Colony-stimulating factor-1 receptor (CSF-1R)-related leukoencephalopathy (CRL) is a neurodegenerative disease that triggers early demyelination, leading to an adult-onset dementia. Triggering receptor expressed on myeloid cells-2 (TREM2) is a microglial receptor that promotes the activation of microglia and phagocytic clearance of apoptotic neurons and myelin debris. We investigated the role of Trem2 in the demyelination observed in the Csf1r+/- mouse model of CRL. We show that elevation of Trem2 expression and callosal demyelination occur in 4-5-month-old Csf1r+/- mice, prior to the development of symptoms. Absence of Trem2 in the Csf1r+/- mouse attenuated myelin pathology and normalized microglial densities and morphology in the corpus callosum. Trem2 absence also prevented axonal degeneration and the loss of cortical layer V neurons observed in Csf1r+/- mice. Furthermore, the absence of Trem2 prevented the accumulation of myelin-derived lipids in Csf1r+/- macrophages and reduced the production of TNF-α after myelin engulfment. These data suggest that TREM2 contributes to microglial dyshomeostasis in CRL.
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Affiliation(s)
- Fabrizio Biundo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Şölen Gökhan
- Institute for Brain Disorders and Neural Regeneration, Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Edward Chen
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jude Oppong-Asare
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - E. Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Abstract
As resident immune cells of the brain, microglia serve pivotal roles in regulating neuronal function under both physiological and pathological conditions, including aging and the most prevalent neurodegenerative disease, Alzheimer's disease (AD). Instructed by neurons, microglia regulate synaptic function and guard brain homeostasis throughout life. Dysregulation of microglial function, however, can lead to dire consequences, including aggravated cognitive decline during aging and exacerbated neuropathology in diseases. The triggering receptor expressed on myeloid cells 2 (TREM2) is a key regulator of microglial function. Loss-of-function variants of TREM2 are associated with an increased risk of AD. TREM2 orchestrates the switch of microglial transcriptome programming that modulates microglial chemotaxis, phagocytosis, and inflammatory responses, as well as microglial regulation of synaptic function in health and disease. Intriguingly, the outcome of microglial/TREM2 function is influenced by age and the context of neuropathology. This review summarizes the rapidly growing research on TREM2 under physiological conditions and in AD, particularly highlighting the impact of TREM2 on neuronal function.
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Affiliation(s)
- Wenhui Qu
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455
| | - Ling Li
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455
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13
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Zheng JY, Li XX, Lin WY, Su S, Wu HC, Hu RD, Pan HF, Ye JH, Cai YF, Zhang SJ. Huang-Lian-Jie-Du decoction alleviates depressive-like behaviors in dextran sulfate sodium-induced colitis mice via Trem2/Dap12 pathway. JOURNAL OF ETHNOPHARMACOLOGY 2023:116658. [PMID: 37263316 DOI: 10.1016/j.jep.2023.116658] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/14/2023] [Accepted: 05/17/2023] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Huang-Lian-Jie-Du decoction (HLJD), a traditional Chinese medicine prescription, has been implicated as effective in treating colitis, depression and inflammation-related diseases. Whether HLJD decoction could ameliorate colitis-induced depression was still unknown and the underlying mechanism was needed to be clarified. AIM OF THE STUDY Our study aimed to explore the effect and the underlying mechanism of HLJD treatment on colitis-induced depression and the involvement of the inflammatory factors and microglial-activated related genes. MATERIALS AND METHODS The chronic colitis model was established by treating male mice with 1% dextran sulfate sodium (DSS) for 8 weeks. One week after DSS-treated, HLJD decoction was administered orally with 2 and 4 g/kg daily for 7 weeks. Behavior tests (Open field/Elevated plus maze/Novel object recognition) and TUNEL staining were then assessed. The expression of inflammatory-related genes and microglial dysregulation were measured by RT-PCR and the expression of Trem2, Danp12 and Iba1 were assessed by immunofluorescence methods. RESULTS Depressive-like behaviors were observed in mice treated with DSS, which suffered colitis. Compared to normal control (NC-V) mice, the density of TUNEL + cells in the habenula (Hb), hippocampus (HIP), and cortex were significantly higher in colitis (DSS-V) mice, especially in Hb. Compared to NC-V and several brain regions, the expression levels of the Il-1β, Il-10 and Dap12 mRNA were significantly increased in the lateral habenula (LHb) of colitis mice. Moreover, the expression of Trem2, Dap12 and Iba1 were increased in LHb of DSS-V mice. HLJD treatment could alleviate depressive-like behaviors, reduce the density of TUNEL + cells in Hb and the expression of Il-6, Il-10 and Dap12 mRNA in LHb of DSS-V mice. The overexpression of Trem2, Dap12 and Iba1 in LHb of DSS-V mice were reversed after HLJD treatment. CONCLUSION These results reveal LHb is an important brain region during the process of colitis-induced depression. HLJD treatment could alleviates depressive-like behaviors in colitis mice via inhibiting the Trem2/Dap12 pathway in microglia of LHb, which would contribute to the precise treatment. It provides a potential mechanistic explanation for the effectiveness of HLJD treatment in colitis patients with depression.
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Affiliation(s)
- Jia-Yi Zheng
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China; Postdoctoral Research Station of Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China; Research Center for Chinese Medicine Innovation, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, 999077, China
| | - Xiao-Xiao Li
- Research Center for Chinese Medicine Innovation, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, 999077, China; State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation), The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, 518000, China
| | - Wei-Yao Lin
- Guangdong Provincial Key Laboratory of Translational Cancer Research of Chinese Medicines, Joint International Research Laboratory of Translational Cancer Research of Chinese Medicines, International Institute for Translational Chinese Medicine, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Shan Su
- College of Basic Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Hai-Cui Wu
- Shenzhen Key Lab for Food Biological Safety Control, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, 518000, China
| | - Rui-Dan Hu
- Guangdong Provincial Key Laboratory of Translational Cancer Research of Chinese Medicines, Joint International Research Laboratory of Translational Cancer Research of Chinese Medicines, International Institute for Translational Chinese Medicine, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Hua-Feng Pan
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China; Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510000, China
| | - Jiang-Hong Ye
- Department of Anesthesiology, Pharmacology, Physiology & Neuroscience, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, NJ, 07103, USA.
| | - Ye-Feng Cai
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China; Postdoctoral Research Station of Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China.
| | - Shi-Jie Zhang
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China; Postdoctoral Research Station of Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510000, China.
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14
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He H, Zhou Y, Liu L, Cui J, Pei Y, Cao J, Hao X, Guo L, Wang H, Liu H. Bioinformatics analysis reveals lipid metabolism may play an important role in the SiO 2-stimulated rat model. Cell Signal 2023:110716. [PMID: 37224986 DOI: 10.1016/j.cellsig.2023.110716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/16/2023] [Accepted: 05/12/2023] [Indexed: 05/26/2023]
Abstract
Silicosis is a progressive and irreversible common occupational disease caused by long-term inhalation of a large amount of free silica dust. Its pathogenesis is complex, and the existing prevention and treatment methods can not effectively improve silicosis injury. To uncover potential differential genes in silicosis, SiO2-stimulated rats and their control original transcriptomic data sets GSE49144, GSE32147 and GSE30178 were downloaded for further bioinformatics analysis. We used R packages to extract and standardize transcriptome profiles, then screened differential genes, and enriched GO and KEGG pathways through clusterProfiler packages. In addition, we investigated the role of lipid metabolism in the progression of silicosis by qRT-PCR validation and transfection with si-CD36. A total of 426 differential genes were identified in this study. Based on GO and KEGG enrichment analysis, it was found that lipid and atherosclerosis were significantly enriched. qRT-PCR was used to detect the relative expression level of differential genes in this signaling pathway of silicosis rat models. mRNA levels of Abcg1, Il1b, Sod2, Cyba, Cd14, Cxcl2, Ccl3, Cxcl1, Ccl2 and CD36 increased, mRNA levels of Ccl5, Cybb and Il18 decreased. In addition, at the cellular level, SiO2-stimulated lead to lipid metabolism disorder in NR8383, and silencing CD36 inhibited SiO2-induced lipid metabolism disorder. These results indicate that lipid metabolism plays an important role in the progression of silicosis, and the genes and pathways reported in this study may provide new ideas for the pathogenesis of silicosis.
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Affiliation(s)
- Hailan He
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Yuhui Zhou
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Lekai Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Jie Cui
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Yongchao Pei
- School of Clinical Medicine, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Jiahui Cao
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Xiaohui Hao
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Lingli Guo
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Hongli Wang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China.
| | - Heliang Liu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China; Hebei Key Laboratory of Organ Fibrosis, North China University of Science and Technology, Tangshan, Hebei 063210, China.
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15
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Guo X, Li B, Wen C, Zhang F, Xiang X, Nie L, Chen J, Mao L. TREM2 promotes cholesterol uptake and foam cell formation in atherosclerosis. Cell Mol Life Sci 2023; 80:137. [PMID: 37133566 PMCID: PMC11071710 DOI: 10.1007/s00018-023-04786-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/09/2023] [Accepted: 04/24/2023] [Indexed: 05/04/2023]
Abstract
Disordered lipid accumulation in the arterial wall is a hallmark of atherosclerosis. Previous studies found that the expression of triggering receptor expressed on myeloid cells 2 (TREM2), a transmembrane receptor of the immunoglobulin family, is increased in mouse atherosclerotic aortic plaques. However, it remains unknown whether TREM2 plays a role in atherosclerosis. Here we investigated the role of TREM2 in atherosclerosis using ApoE knockout (ApoE-/-) mouse models, primary vascular smooth muscle cells (SMCs), and bone marrow-derived macrophages (BMDMs). In ApoE-/- mice, the density of TREM2-positive foam cells in aortic plaques increased in a time-dependent manner after the mice were fed a high-fat diet (HFD). Compared with ApoE-/- mice, the Trem2-/-/ApoE-/- double-knockout mice showed significantly reduced atherosclerotic lesion size, foam cell number, and lipid burden degree in plaques after HFD feeding. Overexpression of TREM2 in cultured vascular SMCs and macrophages exacerbates lipid influx and foam cell formation by upregulating the expression of the scavenger receptor CD36. Mechanistically, TREM2 inhibits the phosphorylation of p38 mitogen-activated protein kinase and peroxisome proliferator activated-receptor gamma (PPARγ), thereby increasing PPARγ nuclear transcriptional activity and subsequently promoting the transcription of CD36. Our results indicate that TREM2 exacerbates atherosclerosis development by promoting SMC- and macrophage-derived foam cell formation by regulating scavenger receptor CD36 expression. Thus, TREM2 may act as a novel therapeutic target for the treatment of atherosclerosis.
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Affiliation(s)
- Xiaoqing Guo
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Bowei Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Cheng Wen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Feng Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Xuying Xiang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Lei Nie
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jiaojiao Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Ling Mao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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16
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Luo L, Chen J, Wu Q, Yuan B, Hu C, Yang T, Wei H, Li T. Prenatally VPA exposure is likely to cause autistic-like behavior in the rats offspring via TREM2 down-regulation to affect the microglial activation and synapse alterations. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 99:104090. [PMID: 36870407 DOI: 10.1016/j.etap.2023.104090] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/17/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Microglial dysfunction has been reported in the valproic acid (VPA)-induced autism spectrum disorder (ASD) rat models. However, how does prenatal VPA exposure affect microglia remains to be elucidated. The triggering receptor expressed on myeloid cells 2 (TREM2) is revealed to be implicated in a range of microglia functions. However, reports on the association between TREM2 and VPA-induced ASD rat models are scarce. Our results showed that prenatal VPA exposure induced autistic-like behaviors, downregulated the levels of TREM2, up-regulated microglial activation, dysregulated microglial polarization, and altered synapse in offspring. TREM2 overexpression partly ameliorated microglia dysfunction and autistic-like behaviors in prenatal VPA-exposed rats. Our findings demonstrated that prenatally VPA exposure is likely to cause autistic-like behavior in the rat offspring via TREM2 down-regulation to affect the microglial activation, microglial polarization and synaptic pruning of microglia for the first time.
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Affiliation(s)
- Lijuan Luo
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Jie Chen
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Qionghui Wu
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Binlin Yuan
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Chaoqun Hu
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Ting Yang
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Hua Wei
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Department of Child Health Care, Children's Hospital of Chongqing Medical University, Chongqing, China.
| | - Tingyu Li
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Child Nutrition and Health, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China; Department of Child Health Care, Children's Hospital of Chongqing Medical University, Chongqing, China.
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17
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Popescu AS, Butler CA, Allendorf DH, Piers TM, Mallach A, Roewe J, Reinhardt P, Cinti A, Redaelli L, Boudesco C, Pradier L, Pocock JM, Thornton P, Brown GC. Alzheimer's disease-associated R47H TREM2 increases, but wild-type TREM2 decreases, microglial phagocytosis of synaptosomes and neuronal loss. Glia 2023; 71:974-990. [PMID: 36480007 PMCID: PMC10952257 DOI: 10.1002/glia.24318] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/22/2022] [Accepted: 11/25/2022] [Indexed: 12/14/2022]
Abstract
Triggering receptor on myeloid cells 2 (TREM2) is an innate immune receptor, upregulated on the surface of microglia associated with amyloid plaques in Alzheimer's disease (AD). Individuals heterozygous for the R47H variant of TREM2 have greatly increased risk of developing AD. We examined the effects of wild-type (WT), R47H and knock-out (KO) of human TREM2 expression in three microglial cell systems. Addition of mouse BV-2 microglia expressing R47H TREM2 to primary mouse neuronal cultures caused neuronal loss, not observed with WT TREM2. Neuronal loss was prevented by using annexin V to block exposed phosphatidylserine, an eat-me signal and ligand of TREM2, suggesting loss was mediated by microglial phagocytosis of neurons exposing phosphatidylserine. Addition of human CHME-3 microglia expressing R47H TREM2 to LUHMES neuronal-like cells also caused loss compared to WT TREM2. Expression of R47H TREM2 in BV-2 and CHME-3 microglia increased their uptake of phosphatidylserine-beads and synaptosomes versus WT TREM2. Human iPSC-derived microglia with heterozygous R47H TREM2 had increased phagocytosis of synaptosomes vs common-variant TREM2. Additionally, phosphatidylserine liposomes increased activation of human iPSC-derived microglia expressing homozygous R47H TREM2 versus common-variant TREM2. Finally, overexpression of TREM2 in CHME-3 microglia caused increased expression of cystatin F, a cysteine protease inhibitor, and knock-down of cystatin F increased CHME-3 uptake of phosphatidylserine-beads. Together, these data suggest that R47H TREM2 may increase AD risk by increasing phagocytosis of synapses and neurons via greater activation by phosphatidylserine and that WT TREM2 may decrease microglial phagocytosis of synapses and neurons via cystatin F.
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Affiliation(s)
- Alma S. Popescu
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Claire A. Butler
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Neuroscience, BioPharmaceuticals R&DAstraZenecaCambridgeUK
| | | | - Thomas M. Piers
- Department of NeuroinflammationUCL Queen Square Institute of NeurologyLondonUK
| | - Anna Mallach
- Department of NeuroinflammationUCL Queen Square Institute of NeurologyLondonUK
| | - Julian Roewe
- Neuroscience DiscoveryAbbVie Deutschland GmbH & Co. KGLudwigshafenGermany
| | - Peter Reinhardt
- Neuroscience DiscoveryAbbVie Deutschland GmbH & Co. KGLudwigshafenGermany
| | | | | | | | | | - Jennifer M. Pocock
- Department of NeuroinflammationUCL Queen Square Institute of NeurologyLondonUK
| | - Peter Thornton
- Neuroscience, BioPharmaceuticals R&DAstraZenecaCambridgeUK
| | - Guy C. Brown
- Department of BiochemistryUniversity of CambridgeCambridgeUK
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18
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Birkle TJY, Brown GC. Syk inhibitors protect against microglia-mediated neuronal loss in culture. Front Aging Neurosci 2023; 15:1120952. [PMID: 37009452 PMCID: PMC10050448 DOI: 10.3389/fnagi.2023.1120952] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 02/28/2023] [Indexed: 03/17/2023] Open
Abstract
Microglia are brain macrophages and play beneficial and/or detrimental roles in many brain pathologies because of their inflammatory and phagocytic activity. Microglial inflammation and phagocytosis are thought to be regulated by spleen tyrosine kinase (Syk), which is activated by multiple microglial receptors, including TREM2 (Triggering Receptor Expressed on Myeloid Cells 2), implicated in neurodegeneration. Here, we have tested whether Syk inhibitors can prevent microglia-dependent neurodegeneration induced by lipopolysaccharide (LPS) in primary neuron-glia cultures. We found that the Syk inhibitors BAY61-3606 and P505-15 (at 1 and 10 μM, respectively) completely prevented the neuronal loss induced by LPS, which was microglia-dependent. Syk inhibition also prevented the spontaneous loss of neurons from older neuron-glia cultures. In the absence of LPS, Syk inhibition depleted microglia from the cultures and induced some microglial death. However, in the presence of LPS, Syk inhibition had relatively little effect on microglial density (reduced by 0-30%) and opposing effects on the release of two pro-inflammatory cytokines (IL-6 decreased by about 45%, TNFα increased by 80%). Syk inhibition also had no effect on the morphological transition of microglia exposed to LPS. On the other hand, inhibition of Syk reduced microglial phagocytosis of beads, synapses and neurons. Thus, Syk inhibition in this model is most likely neuroprotective by reducing microglial phagocytosis, however, the reduced microglial density and IL-6 release may also contribute. This work adds to increasing evidence that Syk is a key regulator of the microglial contribution to neurodegenerative disease and suggests that Syk inhibitors may be used to prevent excessive microglial phagocytosis of synapses and neurons.
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Affiliation(s)
| | - Guy C. Brown
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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19
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Dundee JM, Puigdellívol M, Butler R, Cockram TOJ, Brown GC. P2Y 6 receptor-dependent microglial phagocytosis of synapses mediates synaptic and memory loss in aging. Aging Cell 2022; 22:e13761. [PMID: 36565471 PMCID: PMC9924939 DOI: 10.1111/acel.13761] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/15/2022] [Accepted: 12/08/2022] [Indexed: 12/25/2022] Open
Abstract
Aging causes loss of brain synapses and memory, and microglial phagocytosis of synapses may contribute to this loss. Stressed neurons can release the nucleotide UTP, which is rapidly converted into UDP, that in turn activates the P2Y6 receptor (P2Y6 R) on the surface of microglia, inducing microglial phagocytosis of neurons. However, whether the activation of P2Y6 R affects microglial phagocytosis of synapses is unknown. We show here that inactivation of P2Y6 R decreases microglial phagocytosis of isolated synapses (synaptosomes) and synaptic loss in neuronal-glial co-cultures. In vivo, wild-type mice aged from 4 to 17 months exhibited reduced synaptic density in cortical and hippocampal regions, which correlated with increased internalization of synaptic material within microglia. However, this aging-induced synaptic loss and internalization were absent in P2Y6 R knockout mice, and these mice also lacked any aging-induced memory loss. Thus, P2Y6 R appears to mediate aging-induced loss of synapses and memory by increasing microglial phagocytosis of synapses. Consequently, blocking P2Y6 R has the potential to prevent age-associated memory impairment.
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Affiliation(s)
- Jacob M. Dundee
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Mar Puigdellívol
- Department of BiochemistryUniversity of CambridgeCambridgeUK,Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
| | - Richard Butler
- The Wellcome Trust Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUK
| | | | - Guy C. Brown
- Department of BiochemistryUniversity of CambridgeCambridgeUK
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20
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Winfree RL, Dumitrescu L, Blennow K, Zetterberg H, Gifford KA, Pechman KR, Jefferson AL, Hohman TJ. Biological correlates of elevated soluble TREM2 in cerebrospinal fluid. Neurobiol Aging 2022; 118:88-98. [PMID: 35908327 PMCID: PMC9707345 DOI: 10.1016/j.neurobiolaging.2022.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 11/30/2022]
Abstract
Cerebrospinal fluid (CSF) soluble triggering receptor expressed on myeloid cells-2 (sTREM2) is an emerging biomarker of neuroinflammation in Alzheimer's disease (AD). Yet, sTREM2 expression has not been systematically evaluated in relation to concomitant drivers of neuroinflammation. While associations between sTREM2 and tau in CSF are established, we sought to determine additional biological correlates of CSF sTREM2 during the prodromal stages of AD by evaluating CSF Aβ species (Aβx-40), a fluid biomarker of blood-brain barrier integrity (CSF/plasma albumin ratio), and CSF biomarkers of neurodegeneration measured in 155 participants from the Vanderbilt Memory and Aging Project. A novel association between high CSF levels of both sTREM2 and Aβx-40 was observed and replicated in an independent dataset. Aβx-40 levels, as well as the CSF/plasma albumin ratio, explained additional and unique variance in sTREM2 levels above and beyond that of CSF biomarkers of neurodegeneration. The component of sTREM2 levels correlated with Aβx-40 levels best predicted future cognitive performance. We highlight potential contributions of Aβ homeostasis and blood-brain barrier integrity to elevated CSF sTREM2, underscoring novel biomarker associations relevant to disease progression and clinical outcome measures.
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Affiliation(s)
- Rebecca L Winfree
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Pharmacology Department, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Logan Dumitrescu
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK
| | - Katherine A Gifford
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kimberly R Pechman
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Angela L Jefferson
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy J Hohman
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA; Pharmacology Department, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
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Hoogland ICM, Yik J, Westhoff D, Engelen-Lee JY, Valls Seron M, Man WK, Houben-Weerts JHPM, Tanck MW, van Westerloo DJ, van der Poll T, van Gool WA, van de Beek D. Microglial Response in Triggering Receptor Expressed on Myeloid Cells 2 (Trem2) Knock-Out Mice After Systemic Stimulation with Escherichia Coli. Neurosci Lett 2022; 790:136894. [PMID: 36183964 DOI: 10.1016/j.neulet.2022.136894] [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: 07/08/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND Systemic infection is an important risk factor for delirium, associated with neurodegeneration and subsequent cognitive impairment in older people. Microglial cell response is a known key player in this process and we hypothesize that the triggering receptor expressed on myeloid cells 2 (TREM2) plays an important role in the regulation of this response. METHODS 8- to 10-week old male wild-type (WT) and TREM2 knock-out (Trem2-/-) mice were intraperitoneally inoculated with live Escherichia coli (E. coli) or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 hours and were sacrificed after 2 and 3 days. Microglial response was determined by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. mRNA expression of pro- and anti-inflammatory mediators was measured to quantify the inflammatory response. RESULTS We observed increased Iba-1 positive cells number in thalamus of Trem2-/- mice at 3d after inoculation compared to WT mice (mean 120 cell/mm2 [SD 8] vs. 105 cell/mm2 [SD 11]; p=0.03). Flow cytometry showed no differences in forward scatter or expression of CD11b, CD45 and CD14 between WT and Trem2-/- mice. The brain mRNA expression levels of tumor necrosis factor alpha (TNF-α) of Trem2-/- mice at 2d were higher compared to WT mice (p=0.003). Higher mRNA expression of interleukin 1 beta (IL-1β), Iba-1, CD11b and mitogen-activated protein kinase 1 (MAPK-1) was found in brain of WT mice at 2d compared to Trem2-/- mice (respectively p=0.02; p=0.001; p=0.03 and p=0.02). In spleen there were no differences in inflammatory mediators, between WT and Trem2-/- mice. INTERPRETATION Although the loss of function of TREM2 during systemic infection led to an increased number of activated microglia in the thalamus, we did not observe a consistent increase in expression of inflammatory genes in the brain. The role of TREM2 in the neuro-inflammatory response following systemic infection therefore appears to be limited.
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Affiliation(s)
- Inge C M Hoogland
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
| | - Jutka Yik
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands
| | - Dunja Westhoff
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
| | - Joo-Yeon Engelen-Lee
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
| | - Merche Valls Seron
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands
| | - Wing-Kit Man
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands
| | - Judith H P M Houben-Weerts
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
| | - Michael W Tanck
- Department of Clinical Epidemiology, Amsterdam University Medical Centres, Location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
| | | | - Tom van der Poll
- Centre of Experimental Molecular Medicine, Amsterdam University Medical Centres, Location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
| | - Willem A van Gool
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
| | - Diederik van de Beek
- Department of Neurology, Amsterdam University Medical Centres, Location Academic Medical Centre, Amsterdam Neuroscience, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.
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22
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Advanced therapeutic strategies targeting microglia: beyond neuroinflammation. Arch Pharm Res 2022; 45:618-630. [PMID: 36166145 DOI: 10.1007/s12272-022-01406-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/19/2022] [Indexed: 11/02/2022]
Abstract
For a long time, microglia have been recognized as the main culprits of neuroinflammatory responses because they are primary phagocytes present in the parenchyma of the central nervous system (CNS). However, with the evolving concept of microglial biology, advanced and precise approaches, rather than the global inhibition of activated microglia, have been proposed in the management of neurological disorders. Yolk sac-derived resident microglia have heterogeneous composition according to brain region, sex, and diseases. They play a key role in the maintenance of CNS homeostasis and as primary phagocytes. The perturbation of microglia development can induce neurodevelopmental disorders. Microglia aggravate or alleviate neuroinflammation according to microenvironment and their spatiotemporal dynamics. They are long-lived cells and repopulate via their proliferation or external monocyte engraft. Based on this evolving concept, understanding advanced therapeutic strategies targeting microglia can give us an opportunity to discover novel therapies for neurological disorders.
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23
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Olguin SL, Patel P, Buchanan CN, Dell'Orco M, Gardiner AS, Cole R, Vaughn LS, Sundararajan A, Mudge J, Allan AM, Ortinski P, Brigman JL, Twiss JL, Perrone-Bizzozero NI. KHSRP loss increases neuronal growth and synaptic transmission and alters memory consolidation through RNA stabilization. Commun Biol 2022; 5:672. [PMID: 35798971 PMCID: PMC9262970 DOI: 10.1038/s42003-022-03594-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/16/2022] [Indexed: 02/04/2023] Open
Abstract
The KH-type splicing regulatory protein (KHSRP) is an RNA-binding protein linked to decay of mRNAs with AU-rich elements. KHSRP was previously shown to destabilize Gap43 mRNA and decrease neurite growth in cultured embryonic neurons. Here, we have tested functions of KHSRP in vivo. We find upregulation of 1460 mRNAs in neocortex of adult Khsrp-/- mice, of which 527 bind to KHSRP with high specificity. These KHSRP targets are involved in pathways for neuronal morphology, axon guidance, neurotransmission and long-term memory. Khsrp-/- mice show increased axon growth and dendritic spine density in vivo. Neuronal cultures from Khsrp-/- mice show increased axon and dendrite growth and elevated KHSRP-target mRNAs, including subcellularly localized mRNAs. Furthermore, neuron-specific knockout of Khsrp confirms these are from neuron-intrinsic roles of KHSRP. Consistent with this, neurons in the hippocampus and infralimbic cortex of Khsrp-/- mice show elevations in frequency of miniature excitatory postsynaptic currents. The Khsrp-/- mice have deficits in trace conditioning and attention set-shifting tasks compared Khsrp+/+ mice, indicating impaired prefrontal- and hippocampal-dependent memory consolidation with loss of KHSRP. Overall, these results indicate that deletion of KHSRP impairs neuronal development resulting in alterations in neuronal morphology and function by changing post-transcriptional control of neuronal gene expression.
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Affiliation(s)
- Sarah L Olguin
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Priyanka Patel
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Courtney N Buchanan
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Michela Dell'Orco
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Amy S Gardiner
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Robert Cole
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
| | - Lauren S Vaughn
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | | | - Joann Mudge
- National Center for Genome Resources, Santa Fe, NM, 87505, USA
| | - Andrea M Allan
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Pavel Ortinski
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
| | - Jonathan L Brigman
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA.
- Carolina Autism and Neurodevelopment Center, University of South Carolina, Columbia, SC, 29208, USA.
| | - Nora I Perrone-Bizzozero
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
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24
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Ma X, Zhang S, Qin S, Guo J, Yuan J, Qiang R, Zhou S, Cao W, Yang J, Ma F, Chai R. Transcriptomic and epigenomic analyses explore the potential role of H3K4me3 in neomycin-induced cochlear Lgr5+ progenitor cell regeneration of hair cells. Hum Cell 2022; 35:1030-1044. [DOI: 10.1007/s13577-022-00727-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/17/2022] [Indexed: 12/14/2022]
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25
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Li RY, Qin Q, Yang HC, Wang YY, Mi YX, Yin YS, Wang M, Yu CJ, Tang Y. TREM2 in the pathogenesis of AD: a lipid metabolism regulator and potential metabolic therapeutic target. Mol Neurodegener 2022; 17:40. [PMID: 35658903 PMCID: PMC9166437 DOI: 10.1186/s13024-022-00542-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 05/09/2022] [Indexed: 12/13/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a single-pass transmembrane immune receptor that is mainly expressed on microglia in the brain and macrophages in the periphery. Recent studies have identified TREM2 as a risk factor for Alzheimer’s disease (AD). Increasing evidence has shown that TREM2 can affect lipid metabolism both in the central nervous system (CNS) and in the periphery. In the CNS, TREM2 affects the metabolism of cholesterol, myelin, and phospholipids and promotes the transition of microglia into a disease-associated phenotype. In the periphery, TREM2 influences lipid metabolism by regulating the onset and progression of obesity and its complications, such as hypercholesterolemia, atherosclerosis, and nonalcoholic fatty liver disease. All these altered lipid metabolism processes could influence the pathogenesis of AD through several means, including affecting inflammation, insulin resistance, and AD pathologies. Herein, we will discuss a potential pathway that TREM2 mediates lipid metabolism to influence the pathogenesis of AD in both the CNS and periphery. Moreover, we discuss the possibility that TREM2 may be a key factor that links central and peripheral lipid metabolism under disease conditions, including AD. This link may be due to impacts on the integrity of the blood–brain barrier, and we introduce potential pathways by which TREM2 affects the blood–brain barrier. Moreover, we discuss the role of lipids in TREM2-associated treatments for AD. We propose some potential therapies targeting TREM2 and discuss the prospect and limitations of these therapies.
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Affiliation(s)
- Rui-Yang Li
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Qi Qin
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Han-Chen Yang
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Ying-Ying Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ying-Xin Mi
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Yun-Si Yin
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Meng Wang
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Chao-Ji Yu
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Yi Tang
- Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China.
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26
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Chronic exposure of alcohol triggers microglia-mediated synaptic elimination inducing cognitive impairment. Exp Neurol 2022; 353:114061. [DOI: 10.1016/j.expneurol.2022.114061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/10/2022] [Accepted: 03/27/2022] [Indexed: 11/21/2022]
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27
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Ganapathy S. R, Levová K, Kotačková L, Trnka J, Zogala D, Rusz J, Zima T, Devos D, Šonka K, Růžička E, Kalousová M, Dušek P. Increased Transferrin Sialylation Predicts Phenoconversion in Isolated
REM
Sleep Behavior Disorder. Mov Disord 2022; 37:983-992. [PMID: 35128728 PMCID: PMC9305135 DOI: 10.1002/mds.28942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/05/2022] [Accepted: 01/09/2022] [Indexed: 12/20/2022] Open
Abstract
Background Sialic acid–protein interactions are involved in regulating central nervous system immunity; therefore, derangements in sialylation could be involved in neurodegeneration. Objectives We evaluate the differences in serum transferrin sialylation in prodromal and early‐stage Parkinson's disease (PD), its relation to substantia nigra degeneration, and the risk of phenoconversion to manifest disease. Methods Sixty treatment‐naive PD patients; 72 polysomnography‐confirmed isolated rapid eye movement sleep behavior disorder (iRBD) patients, that is, patients with prodromal synucleinopathy; and 46 healthy volunteers aged ≥45 years and drinking ≤60 standard drinks per month were included. The proportion of serum low‐sialylated, carbohydrate‐deficient transferrin (CDT) isoforms was assessed using high‐performance liquid chromatography, and the values were adjusted for alcohol intake (CDTadj). Dopamine transporter single‐photon emission computed tomography (DaT‐SPECT) imaging was performed. In iRBD, phenoconversion risk of DaT‐SPECT and CDTadj was evaluated using Cox regression adjusted for age and sex. Results Median CDTadj was lower in PD (1.1 [interquartile range: 1.0–1.3]%) compared to controls (1.2 [1.1–1.6]%) (P = 0.001). In iRBD, median CDTadj was lower in subjects with abnormal (1.1 [0.9–1.3]%) than normal (1.3 [1.2–1.6]%) DaT‐SPECT (P = 0.005). After a median 44‐month follow‐up, 20% of iRBD patients progressed to a manifest disease. Although iRBD converters and nonconverters did not significantly differ in CDTadj levels (P = 0.189), low CDTadj increased the risk of phenoconversion with hazard ratio 3.2 (P = 0.045) but did not refine the phenoconversion risk associated with abnormal DaT‐SPECT yielding hazard ratio 15.8 (P < 0.001). Conclusions Decreased serum CDTadj is associated with substantia nigra degeneration in synucleinopathies. iRBD patients with low CDTadj are more likely to phenoconvert to manifest disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.
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Affiliation(s)
- Ranjani Ganapathy S.
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Kateřina Levová
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Lenka Kotačková
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Jiří Trnka
- Institute of Nuclear Medicine, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - David Zogala
- Institute of Nuclear Medicine, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Jan Rusz
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
- Department of Circuit Theory, Faculty of Electrical Engineering Czech Technical University in Prague Prague Czech Republic
| | - Tomáš Zima
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - David Devos
- Department of Medical Pharmacology, Expert Center for Parkinson, CHU‐Lille, Lille Neuroscience and Cognition, Inserm, UMR‐S1172, LICEND, NS‐Park Network University of Lille Lille France
| | - Karel Šonka
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Evžen Růžička
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Marta Kalousová
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Petr Dušek
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
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28
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Paasila PJ, Aramideh JA, Sutherland GT, Graeber MB. Synapses, Microglia, and Lipids in Alzheimer's Disease. Front Neurosci 2022; 15:778822. [PMID: 35095394 PMCID: PMC8789683 DOI: 10.3389/fnins.2021.778822] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is characterised by synaptic dysfunction accompanied by the microscopically visible accumulation of pathological protein deposits and cellular dystrophy involving both neurons and glia. Late-stage AD shows pronounced loss of synapses and neurons across several differentially affected brain regions. Recent studies of advanced AD using post-mortem brain samples have demonstrated the direct involvement of microglia in synaptic changes. Variants of the Apolipoprotein E and Triggering Receptors Expressed on Myeloid Cells gene represent important determinants of microglial activity but also of lipid metabolism in cells of the central nervous system. Here we review evidence that may help to explain how abnormal lipid metabolism, microglial activation, and synaptic pathophysiology are inter-related in AD.
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Affiliation(s)
- Patrick J. Paasila
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Jason A. Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Greg T. Sutherland
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
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29
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Li XX, Zhang F. Targeting TREM2 for Parkinson's Disease: Where to Go? Front Immunol 2022; 12:795036. [PMID: 35003116 PMCID: PMC8740229 DOI: 10.3389/fimmu.2021.795036] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/13/2021] [Indexed: 12/16/2022] Open
Abstract
Parkinson’s disease (PD) is one of most common neurodegenerative disorders caused by a combination of environmental and genetic risk factors. Currently, numerous population genetic studies have shown that polymorphisms in myeloid cell-triggered receptor II (TREM2) are associated with a variety of neurodegenerative disorders. Recently, TREM2 has been verified to represent a promising candidate gene for PD susceptibility and progression. For example, the expression of TREM2 was apparently increased in the prefrontal cortex of PD patients. Moreover, the rare missense mutations in TREM2 (rs75932628, p.R47H) was confirmed to be a risk factor of PD. In addition, overexpression of TREM2 reduced dopaminergic neurodegeneration in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine mouse model of PD. Due to the complex pathogenesis of PD, there is still no effective drug treatment. Thus, TREM2 has received increasing widespread attention as a potential therapeutic target. This review focused on the variation of TREM2 in PD and roles of TREM2 in PD pathogenesis, such as excessive-immune inflammatory response, α-Synuclein aggregation and oxidative stress, to further provide evidence for new immune-related biomarkers and therapies for PD.
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Affiliation(s)
- Xiao-Xian Li
- Laboratory Animal Center and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Feng Zhang
- Laboratory Animal Center and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, China.,Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical University, Zunyi, China
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30
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Puigdellívol M, Milde S, Vilalta A, Cockram TOJ, Allendorf DH, Lee JY, Dundee JM, Pampuščenko K, Borutaite V, Nuthall HN, Brelstaff JH, Spillantini MG, Brown GC. The microglial P2Y 6 receptor mediates neuronal loss and memory deficits in neurodegeneration. Cell Rep 2021; 37:110148. [PMID: 34965424 PMCID: PMC8733854 DOI: 10.1016/j.celrep.2021.110148] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/01/2021] [Accepted: 11/29/2021] [Indexed: 12/29/2022] Open
Abstract
Microglia are implicated in neurodegeneration, potentially by phagocytosing neurons, but it is unclear how to block the detrimental effects of microglia while preserving their beneficial roles. The microglial P2Y6 receptor (P2Y6R) - activated by extracellular UDP released by stressed neurons - is required for microglial phagocytosis of neurons. We show here that injection of amyloid beta (Aβ) into mouse brain induces microglial phagocytosis of neurons, followed by neuronal and memory loss, and this is all prevented by knockout of P2Y6R. In a chronic tau model of neurodegeneration (P301S TAU mice), P2Y6R knockout prevented TAU-induced neuronal and memory loss. In vitro, P2Y6R knockout blocked microglial phagocytosis of live but not dead targets and reduced tau-, Aβ-, and UDP-induced neuronal loss in glial-neuronal cultures. Thus, the P2Y6 receptor appears to mediate Aβ- and tau-induced neuronal and memory loss via microglial phagocytosis of neurons, suggesting that blocking this receptor may be beneficial in the treatment of neurodegenerative diseases.
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Affiliation(s)
- Mar Puigdellívol
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK; Department of Biomedicine, School of Medicine, Institute of Neuroscience, University of Barcelona, 08036 Barcelona, Spain
| | - Stefan Milde
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Anna Vilalta
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Tom O J Cockram
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - David H Allendorf
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Jeffrey Y Lee
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Jacob M Dundee
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Katryna Pampuščenko
- Neuroscience Institute, Lithuanian University of Health Sciences, 50009 Kaunas, Lithuania
| | - Vilmante Borutaite
- Neuroscience Institute, Lithuanian University of Health Sciences, 50009 Kaunas, Lithuania
| | - Hugh N Nuthall
- Neuroscience, Eli Lilly Research & Development, Windlesham, Surrey GU20 6PH, UK
| | - Jack H Brelstaff
- Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK
| | | | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
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31
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Saadi F, Chakravarty D, Kumar S, Kamble M, Saha B, Shindler KS, Das Sarma J. CD40L protects against mouse hepatitis virus-induced neuroinflammatory demyelination. PLoS Pathog 2021; 17:e1010059. [PMID: 34898656 PMCID: PMC8699621 DOI: 10.1371/journal.ppat.1010059] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 12/23/2021] [Accepted: 10/23/2021] [Indexed: 11/19/2022] Open
Abstract
Neurotropic mouse hepatitis virus (MHV-A59/RSA59) infection in mice induces acute neuroinflammation due to direct neural cell dystrophy, which proceeds with demyelination with or without axonal loss, the pathological hallmarks of human neurological disease, Multiple sclerosis (MS). Recent studies in the RSA59-induced neuroinflammation model of MS showed a protective role of CNS-infiltrating CD4+ T cells compared to their pathogenic role in the autoimmune model. The current study further investigated the molecular nexus between CD4+ T cell-expressed CD40Ligand and microglia/macrophage-expressed CD40 using CD40L-/- mice. Results demonstrate CD40L expression in the CNS is modulated upon RSA59 infection. We show evidence that CD40L-/- mice are more susceptible to RSA59 induced disease due to reduced microglia/macrophage activation and significantly dampened effector CD4+ T recruitment to the CNS on day 10 p.i. Additionally, CD40L-/- mice exhibited severe demyelination mediated by phagocytic microglia/macrophages, axonal loss, and persistent poliomyelitis during chronic infection, indicating CD40-CD40L as host-protective against RSA59-induced demyelination. This suggests a novel target in designing prophylaxis for virus-induced demyelination and axonal degeneration, in contrast to immunosuppression which holds only for autoimmune mechanisms of inflammatory demyelination. MS is primarily considered an autoimmune CNS disease, but its potential viral etiology cannot be ignored. Myelin-specific CD40L+CD4+ T cells migration into the CNS and resultant neuroinflammation is considered pathogenic in autoimmune MS. In contrast, CD40L+CD4+ T infiltration into the MHV-induced inflamed CNS and their interaction with CD40+ microglia/macrophages are shown to be protective in our study. Considering differential etiology but comparable demyelination and axonal loss, immunosuppressive treatments may not necessarily ameliorate MS in all patients. MHV-induced demyelination in this study indicates that the interaction between CD40L on CD4+T cells and CD40 on microglia/macrophage plays an important protective role against MHV-induced chronic progressive demyelination.
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Affiliation(s)
- Fareeha Saadi
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Debanjana Chakravarty
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Saurav Kumar
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Mithila Kamble
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Bhaskar Saha
- National Centre for Cell Science, Ganeshkhind, Pune, India
| | - Kenneth S. Shindler
- Departments of Ophthalmology and
- Neurology University of Pennsylvania Scheie Eye Institute, Philadelphia, Pennsylvania, United States of America
| | - Jayasri Das Sarma
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
- Departments of Ophthalmology and
- * E-mail:
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Chataigner M, Lucas C, Di Miceli M, Pallet V, Laye S, Mehaignerie A, Bouvret E, Dinel AL, Joffre C. Dietary Fish Hydrolysate Improves Memory Performance Through Microglial Signature Remodeling During Aging. Front Nutr 2021; 8:750292. [PMID: 34888336 PMCID: PMC8650686 DOI: 10.3389/fnut.2021.750292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/01/2021] [Indexed: 12/28/2022] Open
Abstract
Brain aging is characterized by a chronic low-grade inflammation, which significantly impairs cognitive function. Microglial cells, the immunocompetent cells of the brain, present a different phenotype, switching from a homeostatic signature (M0) to a more reactive phenotype called “MGnD” (microglial neurodegenerative phenotype), leading to a high production of pro-inflammatory cytokines. Furthermore, microglial cells can be activated by age-induced gut dysbiosis through the vagus nerve or the modulation of the peripheral immune system. Nutrients, in particular n-3 long chain polyunsaturated fatty acids (LC-PUFAs) and low molecular weight peptides, display powerful immunomodulatory properties, and can thus prevent age-related cognitive decline. The objective of this study was to investigate the effects of n-3 LC-PUFAs and low molecular weight peptides contained in a marine by-product-derived hydrolysate on microglial phenotypes and intestinal permeability and their consequences on cognition in mice. We demonstrated that the hydrolysate supplementation for 8 weeks prevented short- and long-term memory decline during aging. These observations were linked to the modulation of microglial signature. Indeed, the hydrolysate supplementation promoted homeostatic microglial phenotype by increasing TGF-β1 expression and stimulated phagocytosis by increasing Clec7a expression. Moreover, the hydrolysate supplementation promoted anti-inflammatory intestinal pathway and tended to prevent intestinal permeability alteration occurring during aging. Therefore, the fish hydrolysate appears as an interesting candidate to prevent cognitive decline during aging.
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Affiliation(s)
- Mathilde Chataigner
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France.,Abyss Ingredients, Caudan, France
| | - Céline Lucas
- NutriBrain Research and Technology Transfer, NutriNeuro, Bordeaux, France
| | - Mathieu Di Miceli
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France.,Worcester Biomedical Research Group, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
| | - Véronique Pallet
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France
| | - Sophie Laye
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France
| | | | | | - Anne-Laure Dinel
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France.,NutriBrain Research and Technology Transfer, NutriNeuro, Bordeaux, France
| | - Corinne Joffre
- Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, Bordeaux, France
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Carrier M, Šimončičová E, St-Pierre MK, McKee C, Tremblay MÈ. Psychological Stress as a Risk Factor for Accelerated Cellular Aging and Cognitive Decline: The Involvement of Microglia-Neuron Crosstalk. Front Mol Neurosci 2021; 14:749737. [PMID: 34803607 PMCID: PMC8599581 DOI: 10.3389/fnmol.2021.749737] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/16/2021] [Indexed: 12/22/2022] Open
Abstract
The relationship between the central nervous system (CNS) and microglia is lifelong. Microglia originate in the embryonic yolk sac during development and populate the CNS before the blood-brain barrier forms. In the CNS, they constitute a self-renewing population. Although they represent up to 10% of all brain cells, we are only beginning to understand how much brain homeostasis relies on their physiological functions. Often compared to a double-edged sword, microglia hold the potential to exert neuroprotective roles that can also exacerbate neurodegeneration once compromised. Microglia can promote synaptic growth in addition to eliminating synapses that are less active. Synaptic loss, which is considered one of the best pathological correlates of cognitive decline, is a distinctive feature of major depressive disorder (MDD) and cognitive aging. Long-term psychological stress accelerates cellular aging and predisposes to various diseases, including MDD, and cognitive decline. Among the underlying mechanisms, stress-induced neuroinflammation alters microglial interactions with the surrounding parenchymal cells and exacerbates oxidative burden and cellular damage, hence inducing changes in microglia and neurons typical of cognitive aging. Focusing on microglial interactions with neurons and their synapses, this review discusses the disrupted communication between these cells, notably involving fractalkine signaling and the triggering receptor expressed on myeloid cells (TREM). Overall, chronic stress emerges as a key player in cellular aging by altering the microglial sensome, notably via fractalkine signaling deficiency. To study cellular aging, novel positron emission tomography radiotracers for TREM and the purinergic family of receptors show interest for human study.
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Affiliation(s)
- Micaël Carrier
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Eva Šimončičová
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Marie-Kim St-Pierre
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
| | - Chloe McKee
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.,Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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Li L, Du X, Ling H, Li Y, Wu X, Jin A, Yang M. Gene correlation network analysis to identify regulatory factors in sciatic nerve injury. J Orthop Surg Res 2021; 16:622. [PMID: 34663380 PMCID: PMC8522103 DOI: 10.1186/s13018-021-02756-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sciatic nerve injury (SNI), which frequently occurs under the traumatic hip and hip fracture dislocation, induces serious complications such as motor and sensory loss, muscle atrophy, or even disabling. The present work aimed to determine the regulating factors and gene network related to the SNI pathology. METHODS Sciatic nerve injury dataset GSE18803 with 24 samples was divided into adult group and neonate group. Weighted gene co-expression network analysis (WGCNA) was carried out to identify modules associated with SNI in the two groups. Moreover, differentially expressed genes (DEGs) were determined from every group, separately. Subsequently, co-expression network and protein-protein interaction (PPI) network were overlapped to identify hub genes, while functional enrichment and Reactome analysis were used for a comprehensive analysis of potential pathways. GSE30165 was used as the test set for investigating the hub gene involvement within SNI. Gene set enrichment analysis (GSEA) was performed separately using difference between samples and gene expression level as phenotype label to further prove SNI-related signaling pathways. In addition, immune infiltration analysis was accomplished by CIBERSORT. Finally, Drug-Gene Interaction database (DGIdb) was employed for predicting the possible therapeutic agents. RESULTS 14 SNI status modules and 97 DEGs were identified in adult group, while 15 modules and 21 DEGs in neonate group. A total of 12 hub genes was overlapping from co-expression and PPI network. After the results from both test and training sets were overlapped, we verified that the ten real hub genes showed remarkably up-regulation within SNI. According to functional enrichment of hub genes, the above genes participated in the immune effector process, inflammatory responses, the antigen processing and presentation, and the phagocytosis. GSEA also supported that gene sets with the highest significance were mostly related to the cytokine-cytokine receptor interaction. Analysis of hub genes possible related signaling pathways using gene expression level as phenotype label revealed an enrichment involved in Lysosome, Chemokine signaling pathway, and Neurotrophin signaling pathway. Immune infiltration analysis showed that Macrophages M2 and Regulatory T cells may participate in the development of SNI. At last, 25 drugs were screened from DGIdb to improve SNI treatment. CONCLUSIONS The gene expression network is determined in the present work based on the related regulating factors within SNI, which sheds more light on SNI pathology and offers the possible biomarkers and therapeutic targets in subsequent research.
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Affiliation(s)
- Liuxun Li
- Department of Spine Surgery, the First Affiliated Hospital, Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Xiaokang Du
- Department of Spine Surgery, the First Affiliated Hospital, Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Haiqian Ling
- Department of Spine Surgery, the First Affiliated Hospital, Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Yuhang Li
- Department of Joint and Trauma Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xuemin Wu
- Department of Endocrinology, Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen, Guangdong, China
| | - Anmin Jin
- Department of Spine Surgery, ZhuJiang Hospital of Southern Medical University, Southern Medical University, Guangzhou, Guangdong, China
| | - Meiling Yang
- Department of Oncology, Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen, 518034, Guangdong, China.
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Joshi P, Riffel F, Kumar S, Villacampa N, Theil S, Parhizkar S, Haass C, Colonna M, Heneka MT, Arzberger T, Herms J, Walter J. TREM2 modulates differential deposition of modified and non-modified Aβ species in extracellular plaques and intraneuronal deposits. Acta Neuropathol Commun 2021; 9:168. [PMID: 34663480 PMCID: PMC8522217 DOI: 10.1186/s40478-021-01263-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/29/2022] Open
Abstract
Progressive accumulation of Amyloid-β (Aβ) deposits in the brain is a characteristic neuropathological hallmark of Alzheimer’s disease (AD). During disease progression, extracellular Aβ plaques undergo specific changes in their composition by the sequential deposition of different modified Aβ species. Microglia are implicated in the restriction of amyloid deposits and play a major role in internalization and degradation of Aβ. Recent studies showed that rare variants of the Triggering Receptor Expressed on Myeloid cells 2 (TREM2) are associated with an increased risk for AD. Post-translational modifications of Aβ could modulate the interaction with TREM2, and the uptake by microglia. Here, we demonstrate that genetic deletion of TREM2 or expression of a disease associated TREM2 variant in mice lead to differential accumulation of modified and non-modified Aβ species in extracellular plaques and intraneuronal deposits. Human brains with rare TREM2 AD risk variants also showed altered deposition of modified Aβ species in the different brain lesions as compared to cases with the common variant of TREM2. These findings indicate that TREM2 plays a critical role in the development and the composition of Aβ deposits, not only in extracellular plaques, but also intraneuronally, that both could contribute to the pathogenesis of AD.
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36
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Muzio L, Viotti A, Martino G. Microglia in Neuroinflammation and Neurodegeneration: From Understanding to Therapy. Front Neurosci 2021; 15:742065. [PMID: 34630027 PMCID: PMC8497816 DOI: 10.3389/fnins.2021.742065] [Citation(s) in RCA: 169] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/25/2021] [Indexed: 12/19/2022] Open
Abstract
Microglia are the resident macrophages of the central nervous system (CNS) acting as the first line of defense in the brain by phagocytosing harmful pathogens and cellular debris. Microglia emerge from early erythromyeloid progenitors of the yolk sac and enter the developing brain before the establishment of a fully mature blood-brain barrier. In physiological conditions, during brain development, microglia contribute to CNS homeostasis by supporting cell proliferation of neural precursors. In post-natal life, such cells contribute to preserving the integrity of neuronal circuits by sculpting synapses. After a CNS injury, microglia change their morphology and down-regulate those genes supporting homeostatic functions. However, it is still unclear whether such changes are accompanied by molecular and functional modifications that might contribute to the pathological process. While comprehensive transcriptome analyses at the single-cell level have identified specific gene perturbations occurring in the "pathological" microglia, still the precise protective/detrimental role of microglia in neurological disorders is far from being fully elucidated. In this review, the results so far obtained regarding the role of microglia in neurodegenerative disorders will be discussed. There is solid and sound evidence suggesting that regulating microglia functions during disease pathology might represent a strategy to develop future therapies aimed at counteracting brain degeneration in multiple sclerosis, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.
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Affiliation(s)
- Luca Muzio
- Neuroimmunology Unit, Division of Neuroscience, IRCCS San Raffaele Hospital, Vita-Salute San Raffaele University, Milan, Italy
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37
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Zhang H, Li J, Ren J, Sun S, Ma S, Zhang W, Yu Y, Cai Y, Yan K, Li W, Hu B, Chan P, Zhao GG, Belmonte JCI, Zhou Q, Qu J, Wang S, Liu GH. Single-nucleus transcriptomic landscape of primate hippocampal aging. Protein Cell 2021; 12:695-716. [PMID: 34052996 PMCID: PMC8403220 DOI: 10.1007/s13238-021-00852-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 04/24/2021] [Indexed: 12/12/2022] Open
Abstract
The hippocampus plays a crucial role in learning and memory, and its progressive deterioration with age is functionally linked to a variety of human neurodegenerative diseases. Yet a systematic profiling of the aging effects on various hippocampal cell types in primates is still missing. Here, we reported a variety of new aging-associated phenotypic changes of the primate hippocampus. These include, in particular, increased DNA damage and heterochromatin erosion with time, alongside loss of proteostasis and elevated inflammation. To understand their cellular and molecular causes, we established the first single-nucleus transcriptomic atlas of primate hippocampal aging. Among the 12 identified cell types, neural transiently amplifying progenitor cell (TAPC) and microglia were most affected by aging. In-depth dissection of gene-expression dynamics revealed impaired TAPC division and compromised neuronal function along the neurogenesis trajectory; additionally elevated pro-inflammatory responses in the aged microglia and oligodendrocyte, as well as dysregulated coagulation pathways in the aged endothelial cells may contribute to a hostile microenvironment for neurogenesis. This rich resource for understanding primate hippocampal aging may provide potential diagnostic biomarkers and therapeutic interventions against age-related neurodegenerative diseases.
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Affiliation(s)
- Hui Zhang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiaming Li
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- China National Center for Bioinformation, Beijing, 100101, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China
- Sino-Danish Center for Education and Research, Beijing, 101408, China
| | - Jie Ren
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- China National Center for Bioinformation, Beijing, 100101, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Shuhui Sun
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Shuai Ma
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Weiqi Zhang
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- China National Center for Bioinformation, Beijing, 100101, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Yang Yu
- Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Peking University Third Hospital, Beijing, 100191, China
- Stem Cell Research Center, Peking University Third Hospital, Beijing, 100191, China
| | - Yusheng Cai
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Kaowen Yan
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Baoyang Hu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Piu Chan
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China
| | - Guo-Guang Zhao
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | | | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Jing Qu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China.
| | - Si Wang
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China.
- Aging Translational Medicine Center, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
| | - Guang-Hui Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China.
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38
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Hu Y, Li C, Wang X, Chen W, Qian Y, Dai X. TREM2, Driving the Microglial Polarization, Has a TLR4 Sensitivity Profile After Subarachnoid Hemorrhage. Front Cell Dev Biol 2021; 9:693342. [PMID: 34458257 PMCID: PMC8386127 DOI: 10.3389/fcell.2021.693342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/16/2021] [Indexed: 02/05/2023] Open
Abstract
Increasing evidence suggests that triggering receptor expressed on myeloid cells 2 (TREM2) is implicated in the pathophysiology of neuroinflammation. The aim here was to investigate the neuroprotective role of TREM2 and its regulatory mechanism after subarachnoid hemorrhage (SAH). TREM2 siRNA was administered to measure the detrimental role of TREM2 in mediating microglial polarization in vivo and in vitro after experimental SAH. The relationship between Toll-like receptor 4 (TLR4) signaling and TREM2 was further explored. The soluble TREM2 from the cerebrospinal fluid (CSF) of patients with SAH was detected. The results showed that TREM2 mainly located in the microglia and presented a markedly delayed elevation after SAH. TREM2 knockdown triggered increased pro-inflammatory productions, aggravated microglial activities, and further exacerbated neurological dysfunction after SAH. Significantly, TLR4 knockout increased the expression of TREM2, accompanied by ameliorated neuroinflammation and improved neurological function. Corresponding to different clinical Hunt–Hess grades, obviously enhanced accumulation of soluble TREM2 was detected in the CSF of patients with SAH. TREM2 played a pivotal role in mediating microglial polarization after SAH, and the neuroprotective effect of TREM2 might be potentially suppressed by the hyperactive TLR4 in the early phase of SAH. Pharmacological targeting of TREM2 may be a promising strategy for SAH therapy.
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Affiliation(s)
- Yangchun Hu
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Chao Li
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaojian Wang
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Weiwei Chen
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yu Qian
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xingliang Dai
- Department of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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Liu W, Taso O, Wang R, Bayram S, Graham AC, Garcia-Reitboeck P, Mallach A, Andrews WD, Piers TM, Botia JA, Pocock JM, Cummings DM, Hardy J, Edwards FA, Salih DA. Trem2 promotes anti-inflammatory responses in microglia and is suppressed under pro-inflammatory conditions. Hum Mol Genet 2021; 29:3224-3248. [PMID: 32959884 PMCID: PMC7689298 DOI: 10.1093/hmg/ddaa209] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 12/22/2022] Open
Abstract
Genome-wide association studies have reported that, amongst other microglial genes, variants in TREM2 can profoundly increase the incidence of developing Alzheimer’s disease (AD). We have investigated the role of TREM2 in primary microglial cultures from wild type mice by using siRNA to decrease Trem2 expression, and in parallel from knock-in mice heterozygous or homozygous for the Trem2 R47H AD risk variant. The prevailing phenotype of Trem2 R47H knock-in mice was decreased expression levels of Trem2 in microglia, which resulted in decreased density of microglia in the hippocampus. Overall, primary microglia with reduced Trem2 expression, either by siRNA or from the R47H knock-in mice, displayed a similar phenotype. Comparison of the effects of decreased Trem2 expression under conditions of lipopolysaccharide (LPS) pro-inflammatory or IL-4 anti-inflammatory stimulation revealed the importance of Trem2 in driving a number of the genes up-regulated in the anti-inflammatory phenotype. RNA-seq analysis showed that IL-4 induced the expression of a program of genes including Arg1 and Ap1b1 in microglia, which showed an attenuated response to IL-4 when Trem2 expression was decreased. Genes showing a similar expression profile to Arg1 were enriched for STAT6 transcription factor recognition elements in their promoter, and Trem2 knockdown decreased levels of STAT6. LPS-induced pro-inflammatory stimulation suppressed Trem2 expression, thus preventing TREM2’s anti-inflammatory drive. Given that anti-inflammatory signaling is associated with tissue repair, understanding the signaling mechanisms downstream of Trem2 in coordinating the pro- and anti-inflammatory balance of microglia, particularly mediating effects of the IL-4-regulated anti-inflammatory pathway, has important implications for fighting neurodegenerative disease.
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Affiliation(s)
- Wenfei Liu
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - Orjona Taso
- UK Dementia Research Institute at UCL, London WC1E 6BT, UK
| | - Rui Wang
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | | | | | | | - Anna Mallach
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - William D Andrews
- Department of Cell and Developmental Biology, UCL, London WC1E 6BT, UK
| | - Thomas M Piers
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Juan A Botia
- Department of Information and Communications Engineering, Universidad de Murcia, Murcia E-30100, Spain.,Department of Neurodegenerative Diseases, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Jennifer M Pocock
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Damian M Cummings
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - John Hardy
- UK Dementia Research Institute at UCL, London WC1E 6BT, UK.,Department of Neurodegenerative Diseases, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Frances A Edwards
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - Dervis A Salih
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK.,UK Dementia Research Institute at UCL, London WC1E 6BT, UK
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Lier J, Streit WJ, Bechmann I. Beyond Activation: Characterizing Microglial Functional Phenotypes. Cells 2021; 10:cells10092236. [PMID: 34571885 PMCID: PMC8464670 DOI: 10.3390/cells10092236] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 12/20/2022] Open
Abstract
Classically, the following three morphological states of microglia have been defined: ramified, amoeboid and phagocytic. While ramified cells were long regarded as “resting”, amoeboid and phagocytic microglia were viewed as “activated”. In aged human brains, a fourth, morphologically novel state has been described, i.e., dystrophic microglia, which are thought to be senescent cells. Since microglia are not replenished by blood-borne mononuclear cells under physiological circumstances, they seem to have an “expiration date” limiting their capacity to phagocytose and support neurons. Identifying factors that drive microglial aging may thus be helpful to delay the onset of neurodegenerative diseases, such as Alzheimer’s disease (AD). Recent progress in single-cell deep sequencing methods allowed for more refined differentiation and revealed regional-, age- and sex-dependent differences of the microglial population, and a growing number of studies demonstrate various expression profiles defining microglial subpopulations. Given the heterogeneity of pathologic states in the central nervous system, the need for accurately describing microglial morphology and expression patterns becomes increasingly important. Here, we review commonly used microglial markers and their fluctuations in expression in health and disease, with a focus on IBA1 low/negative microglia, which can be found in individuals with liver disease.
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Affiliation(s)
- Julia Lier
- Institute of Anatomy, University of Leipzig, 04109 Leipzig, Germany;
- Department of Neurology, University of Leipzig, 04109 Leipzig, Germany
- Correspondence:
| | - Wolfgang J. Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32611, USA;
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, 04109 Leipzig, Germany;
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Berdowski WM, Sanderson LE, van Ham TJ. The multicellular interplay of microglia in health and disease: lessons from leukodystrophy. Dis Model Mech 2021; 14:dmm048925. [PMID: 34282843 PMCID: PMC8319551 DOI: 10.1242/dmm.048925] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Microglia are highly dynamic cells crucial for developing and maintaining lifelong brain function and health through their many interactions with essentially all cellular components of the central nervous system. The frequent connection of microglia to leukodystrophies, genetic disorders of the white matter, has highlighted their involvement in the maintenance of white matter integrity. However, the mechanisms that underlie their putative roles in these processes remain largely uncharacterized. Microglia have also been gaining attention as possible therapeutic targets for many neurological conditions, increasing the demand to understand their broad spectrum of functions and the impact of their dysregulation. In this Review, we compare the pathological features of two groups of genetic leukodystrophies: those in which microglial dysfunction holds a central role, termed 'microgliopathies', and those in which lysosomal or peroxisomal defects are considered to be the primary driver. The latter are suspected to have notable microglia involvement, as some affected individuals benefit from microglia-replenishing therapy. Based on overlapping pathology, we discuss multiple ways through which aberrant microglia could lead to white matter defects and brain dysfunction. We propose that the study of leukodystrophies, and their extensively multicellular pathology, will benefit from complementing analyses of human patient material with the examination of cellular dynamics in vivo using animal models, such as zebrafish. Together, this will yield important insight into the cell biological mechanisms of microglial impact in the central nervous system, particularly in the development and maintenance of myelin, that will facilitate the development of new, and refinement of existing, therapeutic options for a range of brain diseases.
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Affiliation(s)
| | | | - Tjakko J. van Ham
- Department of Clinical Genetics, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
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42
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Ji MH, He X, Shen JC, Yang JJ. Aging-Related Neural Disruption Might Predispose to Postoperative Cognitive Impairment Following Surgical Trauma. J Alzheimers Dis 2021; 81:1685-1699. [PMID: 33967044 DOI: 10.3233/jad-201590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Accumulating evidence has demonstrated that aging is associated with an exaggerated response to surgical trauma together with cognitive impairments. This has significant implications for the development of clinical phenotype such as perioperative neurocognitive disorders (PND), which is a common complication following surgery, especially for the elderly. However, the mechanism by which aging brain is vulnerable to surgical trauma remains to be elucidated. OBJECTIVE To test whether age-related alterations in hippocampal network activities contribute to increased risk of PND following surgery. METHODS Thirty-two adult and seventy-two aged male C57BL/6 mice undergone sevoflurane anesthesia and exploratory laparotomy were used to mimic human abdominal surgery. For the interventional study, mice were treated with minocycline. Behavioral tests were performed post-surgery with open field, novel object recognition and fear conditioning tests, respectively. The brain tissues were then harvested and subjected to biochemistry studies. Local field potential (LFP) recording was performed in another separate experiment. RESULTS Aged mice displayed signs of neuroinflammation, as reflected by significantly increased proinflammatory mediators in the hippocampus. Also, aged mice displayed persistently decreased oscillation activities under different conditions, both before and after surgery. Further correlation analysis suggested that theta power was positively associated with time with novel object, while γ oscillation activity was positively associated with freezing time to context. Of note, downregulation of neuroinflammation by microglia inhibitor minocycline reversed some of these abnormities. CONCLUSION Our study highlights that age-related hippocampal oscillation dysregulation increases the risk of PND incidence, which might provide diagnostic/prognostic biomarkers for PND and possible other neurodegenerative diseases.
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Affiliation(s)
- Mu-Huo Ji
- Department of Anesthesiology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xue He
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Jin-Chun Shen
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Jian-Jun Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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43
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Cockram TOJ, Dundee JM, Popescu AS, Brown GC. The Phagocytic Code Regulating Phagocytosis of Mammalian Cells. Front Immunol 2021; 12:629979. [PMID: 34177884 PMCID: PMC8220072 DOI: 10.3389/fimmu.2021.629979] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/18/2021] [Indexed: 01/21/2023] Open
Abstract
Mammalian phagocytes can phagocytose (i.e. eat) other mammalian cells in the body if they display certain signals, and this phagocytosis plays fundamental roles in development, cell turnover, tissue homeostasis and disease prevention. To phagocytose the correct cells, phagocytes must discriminate which cells to eat using a 'phagocytic code' - a set of over 50 known phagocytic signals determining whether a cell is eaten or not - comprising find-me signals, eat-me signals, don't-eat-me signals and opsonins. Most opsonins require binding to eat-me signals - for example, the opsonins galectin-3, calreticulin and C1q bind asialoglycan eat-me signals on target cells - to induce phagocytosis. Some proteins act as 'self-opsonins', while others are 'negative opsonins' or 'phagocyte suppressants', inhibiting phagocytosis. We review known phagocytic signals here, both established and novel, and how they integrate to regulate phagocytosis of several mammalian targets - including excess cells in development, senescent and aged cells, infected cells, cancer cells, dead or dying cells, cell debris and neuronal synapses. Understanding the phagocytic code, and how it goes wrong, may enable novel therapies for multiple pathologies with too much or too little phagocytosis, such as: infectious disease, cancer, neurodegeneration, psychiatric disease, cardiovascular disease, ageing and auto-immune disease.
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Affiliation(s)
| | | | | | - Guy C. Brown
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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44
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Schwab N, Ju Y, Hazrati LN. Early onset senescence and cognitive impairment in a murine model of repeated mTBI. Acta Neuropathol Commun 2021; 9:82. [PMID: 33964983 PMCID: PMC8106230 DOI: 10.1186/s40478-021-01190-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/03/2021] [Indexed: 12/19/2022] Open
Abstract
Mild traumatic brain injury (mTBI) results in broad neurological symptoms and an increased risk of being diagnosed with a neurodegenerative disease later in life. While the immediate oxidative stress response and post-mortem pathology of the injured brain has been well studied, it remains unclear how early pathogenic changes may drive persistent symptoms and confer susceptibility to neurodegeneration. In this study we have used a mouse model of repeated mTBI (rmTBI) to identify early gene expression changes at 24 h or 7 days post-injury (7 dpi). At 24 h post-injury, gene expression of rmTBI mice shows activation of the DNA damage response (DDR) towards double strand DNA breaks, altered calcium and cell–cell signalling, and inhibition of cell death pathways. By 7 dpi, rmTBI mice had a gene expression signature consistent with induction of cellular senescence, activation of neurodegenerative processes, and inhibition of the DDR. At both timepoints gliosis, microgliosis, and axonal damage were evident in the absence of any gross lesion, and by 7 dpi rmTBI also mice had elevated levels of IL1β, p21, 53BP1, DNA2, and p53, supportive of DNA damage-induced cellular senescence. These gene expression changes reflect establishment of processes usually linked to brain aging and suggests that cellular senescence occurs early and most likely prior to the accumulation of toxic proteins. These molecular changes were accompanied by spatial learning and memory deficits in the Morris water maze. To conclude, we have identified DNA damage-induced cellular senescence as a repercussion of repeated mild traumatic brain injury which correlates with cognitive impairment. Pathways involved in senescence may represent viable treatment targets of post-concussive syndrome. Senescence has been proposed to promote neurodegeneration and appears as an effective target to prevent long-term complications of mTBI, such as chronic traumatic encephalopathy and other related neurodegenerative pathologies.
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45
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Chitu V, Biundo F, Shlager GGL, Park ES, Wang P, Gulinello ME, Gokhan Ş, Ketchum HC, Saha K, DeTure MA, Dickson DW, Wszolek ZK, Zheng D, Croxford AL, Becher B, Sun D, Mehler MF, Stanley ER. Microglial Homeostasis Requires Balanced CSF-1/CSF-2 Receptor Signaling. Cell Rep 2021; 30:3004-3019.e5. [PMID: 32130903 DOI: 10.1016/j.celrep.2020.02.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 12/18/2019] [Accepted: 02/06/2020] [Indexed: 02/08/2023] Open
Abstract
CSF-1R haploinsufficiency causes adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). Previous studies in the Csf1r+/- mouse model of ALSP hypothesized a central role of elevated cerebral Csf2 expression. Here, we show that monoallelic deletion of Csf2 rescues most behavioral deficits and histopathological changes in Csf1r+/- mice by preventing microgliosis and eliminating most microglial transcriptomic alterations, including those indicative of oxidative stress and demyelination. We also show elevation of Csf2 transcripts and of several CSF-2 downstream targets in the brains of ALSP patients, demonstrating that the mechanisms identified in the mouse model are functional in humans. Our data provide insights into the mechanisms underlying ALSP. Because increased CSF2 levels and decreased microglial Csf1r expression have also been reported in Alzheimer's disease and multiple sclerosis, we suggest that the unbalanced CSF-1R/CSF-2 signaling we describe in the present study may contribute to the pathogenesis of other neurodegenerative conditions.
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Affiliation(s)
- Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Fabrizio Biundo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Gabriel G L Shlager
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Eun S Park
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maria E Gulinello
- Behavioral Core Facility, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Şölen Gokhan
- Institute for Brain Disorders and Neural Regeneration, Departments of Neurology, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harmony C Ketchum
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kusumika Saha
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Michael A DeTure
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Deyou Zheng
- The Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, and Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Burkhard Becher
- Institute of Experimental Immunology, University of Zurich, Zurich 8057, Switzerland
| | - Daqian Sun
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Mark F Mehler
- Institute for Brain Disorders and Neural Regeneration, Departments of Neurology, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - E Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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46
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Microglial Pruning: Relevance for Synaptic Dysfunction in Multiple Sclerosis and Related Experimental Models. Cells 2021; 10:cells10030686. [PMID: 33804596 PMCID: PMC8003660 DOI: 10.3390/cells10030686] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia, besides being able to react rapidly to a wide range of environmental changes, are also involved in shaping neuronal wiring. Indeed, they actively participate in the modulation of neuronal function by regulating the elimination (or “pruning”) of weaker synapses in both physiologic and pathologic processes. Mounting evidence supports their crucial role in early synaptic loss, which is emerging as a hallmark of several neurodegenerative diseases, including multiple sclerosis (MS) and its preclinical models. MS is an inflammatory, immune-mediated pathology of the white matter in which demyelinating lesions may cause secondary neuronal death. Nevertheless, primitive grey matter (GM) damage is emerging as an important contributor to patients’ long-term disability, since it has been associated with early and progressive cognitive decline (CD), which seriously worsens the quality of life of MS patients. Widespread synapse loss even in the absence of demyelination, axon degeneration and neuronal death has been demonstrated in different GM structures, thus raising the possibility that synaptic dysfunction could be an early and possibly independent event in the neurodegenerative process associated with MS. This review provides an overview of microglial-dependent synapse elimination in the neuroinflammatory process that underlies MS and its experimental models.
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47
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Butler CA, Popescu AS, Kitchener EJA, Allendorf DH, Puigdellívol M, Brown GC. Microglial phagocytosis of neurons in neurodegeneration, and its regulation. J Neurochem 2021; 158:621-639. [PMID: 33608912 DOI: 10.1111/jnc.15327] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/13/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023]
Abstract
There is growing evidence that excessive microglial phagocytosis of neurons and synapses contributes to multiple brain pathologies. RNA-seq and genome-wide association (GWAS) studies have linked multiple phagocytic genes to neurodegenerative diseases, and knock-out of phagocytic genes has been found to protect against neurodegeneration in animal models, suggesting that excessive microglial phagocytosis contributes to neurodegeneration. Here, we review recent evidence that microglial phagocytosis of live neurons and synapses causes neurodegeneration in animal models of Alzheimer's disease and other tauopathies, Parkinson's disease, frontotemporal dementias, multiple sclerosis, retinal degeneration and neurodegeneration induced by ischaemia, infection or ageing. We also review factors regulating microglial phagocytosis of neurons, including: nucleotides, frackalkine, phosphatidylserine, calreticulin, UDP, CD47, sialylation, complement, galectin-3, Apolipoprotein E, phagocytic receptors, Siglec receptors, cytokines, microglial epigenetics and expression profile. Some of these factors may be potential treatment targets to prevent neurodegeneration mediated by excessive microglial phagocytosis of live neurons and synapses.
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Affiliation(s)
- Claire A Butler
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Alma S Popescu
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | | | - Mar Puigdellívol
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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48
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Safaiyan S, Besson-Girard S, Kaya T, Cantuti-Castelvetri L, Liu L, Ji H, Schifferer M, Gouna G, Usifo F, Kannaiyan N, Fitzner D, Xiang X, Rossner MJ, Brendel M, Gokce O, Simons M. White matter aging drives microglial diversity. Neuron 2021; 109:1100-1117.e10. [PMID: 33606969 DOI: 10.1016/j.neuron.2021.01.027] [Citation(s) in RCA: 198] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/08/2020] [Accepted: 01/26/2021] [Indexed: 01/08/2023]
Abstract
Aging results in gray and white matter degeneration, but the specific microglial responses are unknown. Using single-cell RNA sequencing from white and gray matter separately, we identified white matter-associated microglia (WAMs), which share parts of the disease-associated microglia (DAM) gene signature and are characterized by activation of genes implicated in phagocytic activity and lipid metabolism. WAMs depend on triggering receptor expressed on myeloid cells 2 (TREM2) signaling and are aging dependent. In the aged brain, WAMs form independent of apolipoprotein E (APOE), in contrast to mouse models of Alzheimer's disease, in which microglia with the WAM gene signature are generated prematurely and in an APOE-dependent pathway similar to DAMs. Within the white matter, microglia frequently cluster in nodules, where they are engaged in clearing degenerated myelin. Thus, WAMs may represent a potentially protective response required to clear degenerated myelin accumulating during white matter aging and disease.
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Affiliation(s)
- Shima Safaiyan
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Simon Besson-Girard
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Tuğberk Kaya
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Ludovico Cantuti-Castelvetri
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Lu Liu
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Hao Ji
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Garyfallia Gouna
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Fumere Usifo
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Nirmal Kannaiyan
- Department of Psychiatry, Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - Dirk Fitzner
- Department of Neurology, University of Göttingen, 37075 Göttingen, Germany
| | - Xianyuan Xiang
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität Munich, 81377 Munich, Germany
| | - Moritz J Rossner
- Department of Psychiatry, Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Ozgun Gokce
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), 81377 Munich, Germany.
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), 81377 Munich, Germany.
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Zheng RZ, Xing J, Huang Q, Yang XT, Zhao CY, Li XY. Integration of single-cell and bulk RNA sequencing data reveals key cell types and regulators in traumatic brain injury. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:1201-1214. [PMID: 33757183 DOI: 10.3934/mbe.2021065] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Traumatic brain injury (TBI) is a leading cause of disability and mortality worldwide, whose symptoms ranging from mild to severe, even life-threatening. However, specific cell types and key regulators involved in traumatic brain injury have not been well elucidated. In this study, utilizing single-cell RNA-seq (scRNA-seq) data from mice with TBI, we have successfully identified and characterized 13 cell populations including astrocytes, oligodendrocyte, newly formed oligodendrocytes, microglia, two types of endothelial cells, five types of excitatory and two types of inhibitory neurons. Differential expression analysis and gene set enrichment analysis (GSEA) revealed the upregulation of microglia and endothelial markers, along with the downregulation of markers of excitatory neurons in TBI. The cell-cell communication analysis revealed that microglia and endothelial cell might interact through the interaction of Icam1-Il2rg and C1qa-Cd93, and microglia might also communicate with each other via Icam1-Itagm. The autocrine ligand-receptor in microglia might result in activation of TYROBP causal network via Icam1-Itgam. The cell-cell contact between microglia and endothelial cell might activate integrin signaling pathways. Moreover, we also found that genes involved in microglia activation were highly downregulated in Tyrobp/Dap12-deficient microglia, indicating that the upregulation of Tyrobp and TYROBP causal network in microglia might be a candidate therapeutic target in TBI. In contrast, the excitatory neurons were involved in maintaining normal brain function, and their inactivation might cause dysfunction of nervous system in TBI patients. In conclusion, the present study has discerned major cell types such as microglia, endothelial cells and excitatory neurons, and revealed key regulator such as TYROBP, C1QA, and CD93 in TBI, which shall improve our understanding of the pathogenesis of TBI.
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Affiliation(s)
- Rui-Zhe Zheng
- Department of Neurosurgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Jin Xing
- Department of Neurosurgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 201399, China
| | - Qiong Huang
- Department of Neurology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Xi-Tao Yang
- Department of Neurosurgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chang-Yi Zhao
- Department of Neurosurgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Xin-Yuan Li
- Department of Neurosurgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
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50
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Konishi H, Kiyama H. Non-pathological roles of microglial TREM2/DAP12: TREM2/DAP12 regulates the physiological functions of microglia from development to aging. Neurochem Int 2020; 141:104878. [DOI: 10.1016/j.neuint.2020.104878] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/03/2020] [Accepted: 10/06/2020] [Indexed: 01/01/2023]
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