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Amir A, Shahid M, Farooq Khan S, Nisar U, Faizi S, Usman Simjee S. Nicotinic acid modulates microglial TREM-2 gene in Phytohaemagglutinin-Induced in vitro model of Alzheimer's disease like pathology. Brain Res 2024; 1824:148686. [PMID: 38008243 DOI: 10.1016/j.brainres.2023.148686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 11/28/2023]
Abstract
Alzheimer's disease (AD) is a multifactorial,neurodegenerative disorder linked withextracellular amyloid beta (Aβ) plaques deposition and formation of intracellular neurofibrillary tangles (NFTs). Currently, no effective therapies are available to cure AD. Neuroinflammation isa well-known hallmark in the onset and advancement of AD and triggering receptor expressed on myeloid cells-2 (TREM-2), a microglial gene, is responsible for regulating inflammatory responses and clearance of cellular debris. Loss of TREM-2functionincreases neuroinflammation associated expression of pro-inflammatory markersthus resultingin reduced clearance of Aβ that further aid in disease progression.Therefore, targeting neuroinflammation is a good therapeutic approach for AD. This study aimed to determine the neuroprotective effect of nicotinic acid (NA) in vitro model of AD-like pathology induced in F-98 cell line using Phytohemagglutinin (PHA). MTT assay was employed for checking the cell viability as well as the proliferation of the cells following treatment with NA. PHA at the concentration of 10 μg/mL produces maximum plaques. The neuroprotective effect of NA was next evaluated against PHA-induced plaques and it was observed that NA reverses the damages induced by PHA i.e., by inhibiting the clustering of the cells and replacing the damaged cells with the new ones. Further, NA also increased the expression of TREM-2/DAP-12 with parallel decreased in the expression of IL-1β, TNF-α and iNOS. It also successfully altered disease associated ADAM-10 and BACE-1 compared to PHA control. These findings suggest that NA might be considered as a good therapeutic candidate for the treatment of neurodegenerative disorders like AD.
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Affiliation(s)
- Aiman Amir
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Maha Shahid
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Sarosh Farooq Khan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Uzair Nisar
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Shaheen Faizi
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Shabana Usman Simjee
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
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Qu S, Hu S, Xu H, Wu Y, Ming S, Zhan X, Wang C, Huang X. TREM-2 Drives Development of Multiple Sclerosis by Promoting Pathogenic Th17 Polarization. Neurosci Bull 2024; 40:17-34. [PMID: 37498431 PMCID: PMC10774236 DOI: 10.1007/s12264-023-01094-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 05/07/2023] [Indexed: 07/28/2023] Open
Abstract
Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease, mediated by pathogenic T helper 17 (Th17) cells. However, the therapeutic effect is accompanied by the fluctuation of the proportion and function of Th17 cells, which prompted us to find the key regulator of Th17 differentiation in MS. Here, we demonstrated that the triggering receptor expressed on myeloid cells 2 (TREM-2), a modulator of pattern recognition receptors on innate immune cells, was highly expressed on pathogenic CD4-positive T lymphocyte (CD4+ T) cells in both patients with MS and experimental autoimmune encephalomyelitis (EAE) mouse models. Conditional knockout of Trem-2 in CD4+ T cells significantly alleviated the disease activity and reduced Th17 cell infiltration, activation, differentiation, and inflammatory cytokine production and secretion in EAE mice. Furthermore, with Trem-2 knockout in vivo experiments and in vitro inhibitor assays, the TREM-2/zeta-chain associated protein kinase 70 (ZAP70)/signal transducer and activator of transcription 3 (STAT3) signal axis was essential for Th17 activation and differentiation in EAE progression. In conclusion, TREM-2 is a key regulator of pathogenic Th17 in EAE mice, and this sheds new light on the potential of this therapeutic target for MS.
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Affiliation(s)
- Siying Qu
- Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China
| | - Shengfeng Hu
- The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy and Clinical Immunology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Huiting Xu
- Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China
| | - Yongjian Wu
- Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China
| | - Siqi Ming
- Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China
| | - Xiaoxia Zhan
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Cheng Wang
- Division of Nephrology, Department of Medicine, the Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China
| | - Xi Huang
- Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, 519000, China.
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Zhang C, Xu C, Jing Y, Cao H, Wang X, Zhao J, Gong Q, Chen S. Deferoxamine Induces Autophagy Following Traumatic Brain Injury via TREM2 on Microglia. Mol Neurobiol 2023:10.1007/s12035-023-03875-x. [PMID: 38110648 DOI: 10.1007/s12035-023-03875-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023]
Abstract
Previous studies have indicated that iron disorder, inflammation, and autophagy play an important role in traumatic brain injury (TBI). The triggering receptor expressed on myeloid cells 2 (TREM2), an immunoglobulin superfamily transmembrane receptor, is involved in inflammation. However, the role of TREM2 in modulating the microglia response in TBI has been rarely investigated. The present study aimed to investigate if the iron chelator deferoxamine (DFO) could ameliorate TBI through autophagy mediated by the TREM2. TBI was developed by the controlled cortical impact (CCI) mouse model and stretching of individual primary cortical microglia taken from the tissue of the rat brain. DFO was intraperitoneally used for intervention. Western blotting assay, qRT-PCR, TUNEL staining, immunofluorescence staining, confocal microscopy analysis, transmission electron microscopy, H&E staining, brain water content measurement, and the neurobehavioral assessments were performed. TREM2 expression was up-regulated in cortex of TBI mice model and in microglia stretching model, which was attenuated by DFO. After the mice were subjected to CCI, DFO treatment significantly up-regulated the protein levels of autophagy compared with the TBI group at 3 days and caused an increase of autophagic vacuoles. Treatment with DFO reduced TBI-induced cell apoptosis, cerebral edema, neuroinflammation, and motor function impairment in mice, at least partly via the mTOR signaling pathway that facilitates the TREM2 activity. The results indicated that the maintenance of iron homeostasis by DFO plays neuroprotection by modulating the inflammatory response to TBI through TREM2-mediated autophagy. This study suggested that TREM2-mediated autophagy might be a potential target for therapeutic intervention in TBI.
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Affiliation(s)
- Chunhao Zhang
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Chen Xu
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Yao Jing
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Heli Cao
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Xuyang Wang
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Jianwei Zhao
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Qiuyuan Gong
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Shiwen Chen
- Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
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Jiang C, Chen Z, Wang X, Zhang Y, Guo X, Fan H, Huang D, He Y, Tang X, Ai Y, Liu Y, Yang H, Hao D. Curcumin-activated Olfactory Ensheathing Cells Improve Functional Recovery After Spinal Cord Injury by Modulating Microglia Polarization Through APOE/TREM2/NF-κB Signaling Pathway. J Neuroimmune Pharmacol 2023; 18:476-494. [PMID: 37658943 PMCID: PMC10577109 DOI: 10.1007/s11481-023-10081-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 08/02/2023] [Indexed: 09/05/2023]
Abstract
Transplantation of curcumin-activated olfactory ensheathing cells (aOECs) improved functional recovery in spinal cord injury (SCI) rats. Nevertheless, little is known considering the underlying mechanisms. At the present study, we investigated the promotion of regeneration and functional recovery after transplantation of aOECs into rats with SCI and the possible underlying molecular mechanisms. Primary OECs were prepared from the olfactory bulb of rats, followed by treatment with 1µM CCM at 7-10 days of culture, resulting in cell activation. Concomitantly, rat SCI model was developed to evaluate the effects of transplantation of aOECs in vivo. Subsequently, microglia were isolated, stimulated with 100 ng/mL lipopolysaccharide (LPS) for 24 h to polarize to M1 phenotype and treated by aOECs conditional medium (aOECs-CM) and OECs conditional medium (OECs-CM), respectively. Changes in the expression of pro-inflammatory and anti-inflammatory phenotypic markers expression were detected using western blotting and immunofluorescence staining, respectively. Finally, a series of molecular biological experiments including knock-down of triggering receptor expressed on myeloid cells 2 (TREM2) and analysis of the level of apolipoprotein E (APOE) expression were performed to investigate the underlying mechanism of involvement of CCM-activated OECs in modulating microglia polarization, leading to neural regeneration and function recovery. CCM-activated OECs effectively attenuated deleterious inflammation by regulating microglia polarization from the pro-inflammatory (M1) to anti-inflammatory (M2) phenotype in SCI rats and facilitated functional recovery after SCI. In addition, microglial polarization to M2 elicited by aOECs-CM in LPS-induced microglia was effectively reversed when TREM2 expression was downregulated. More importantly, the in vitro findings indicated that aOECs-CM potentiating LPS-induced microglial polarization to M2 was partially mediated by the TREM2/nuclear factor kappa beta (NF-κB) signaling pathway. Besides, the expression of APOE significantly increased in CCM-treated OECs. CCM-activated OECs could alleviate inflammation after SCI by switching microglial polarization from M1 to M2, which was likely mediated by the APOE/TREM2/NF-κB pathway, and thus ameliorated neurological function. Therefore, the present finding is of paramount significance to enrich the understanding of underlying molecular mechanism of aOECs-based therapy and provide a novel therapeutic approach for treatment of SCI.
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Affiliation(s)
- Chao Jiang
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Zhe Chen
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Xiaohui Wang
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Yongyuan Zhang
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Xinyu Guo
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
- Translational Medicine Center, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
| | - Hong Fan
- Translational Medicine Center, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Department of Neurology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, 710004 China
| | - Dageng Huang
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Yuqing He
- Translational Medicine Center, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
| | - Xiangwen Tang
- Translational Medicine Center, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Basic Medical School Academy, Shaanxi University of Traditional Chinese Medicine, Xianyang, 712046 China
| | - Yixiang Ai
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Youjun Liu
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
| | - Hao Yang
- Translational Medicine Center, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
| | - Dingjun Hao
- Department of Spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Xi’an, 710054 China
- Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
- Department of spine Surgery, Hong Hui Hospital, Xi’an Jiaotong University, Shaanxi Key Laboratory of Spine Bionic Treatment, Xi’an, 710054 China
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Luo L, Li T, Wu Q, Yuan B, Hu C, Yang T, Wei H, Chen J. Retinoic acid administration normalizes aberrant microglial activation via regulating TREM2 transcription in the PFC of valproic acid induced autism rat. Neurosci Lett 2023; 803:137193. [PMID: 36924930 DOI: 10.1016/j.neulet.2023.137193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/12/2023] [Accepted: 03/13/2023] [Indexed: 03/15/2023]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disease with an unclear underlying pathogenesis. Disruption of retinoic acid (RA)-retinoic acid receptor α (RARα) signaling and aberrant microglial activation were reported to be involved in the pathogenesis of ASD. However, the effect of RA-RARα signaling on microglial activation in ASD and the underlying mechanisms are unknown. Herein, we found inhibited RA-RARα signaling and increased microglial activation in valproic acid (VPA)-induced autism rats. Furthermore, we administered RA to VPA rats and found that RA ameliorated autism-like behaviors, inhibited microglial activation and normalized microglial polarization in VPA rats. Additionally, the expression levels of RARα and triggering receptor expressed on myeloid cells 2 (TREM2) were increased in the prefrontal cortex (PFC) of VPA rats given RA. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays confirmed that RARα can regulate the transcriptional activity of the TREM2 gene by binding to its promoter. We conclude that RA administration ameliorates autism-like behaviors in VPA rats by inhibiting microglial activation and normalizing microglial polarization through the regulation of TREM2 transcription by RARα.
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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
| | - 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
| | - 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.
| | - 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.
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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. Environ Toxicol Pharmacol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Xu J, Zhang L, Li M, He X, Luo J, Wu R, Hong Z, Zheng H, Hu X. TREM2 mediates physical exercise-promoted neural functional recovery in rats with ischemic stroke via microglia-promoted white matter repair. J Neuroinflammation 2023; 20:50. [PMID: 36829205 PMCID: PMC9960657 DOI: 10.1186/s12974-023-02741-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/17/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND The repair of white matter injury is of significant importance for functional recovery after ischemic stroke, and the up-regulation of triggering receptors expressed on myeloid cells 2 (TREM2) after ischemic stroke is neuroprotective and implicated in remyelination. However, the lack of effective therapies calls for the need to investigate the regenerative process of remyelination and the role of rehabilitation therapy. This study sought to investigate whether and how moderate physical exercise (PE) promotes oligodendrogenesis and remyelination in rats with transient middle cerebral artery occlusion (tMCAO). METHODS Male Sprague-Dawley rats (weighing 250-280 g) were subjected to tMCAO. AAV-shRNA was injected into the lateral ventricle to silence the Trem2 gene before the operation. The rats in the physical exercise group started electric running cage training at 48 h after the operation. The Morris water maze and novel object recognition test were used to evaluate cognitive function. Luxol fast blue staining, diffusion tensor imaging, and electron microscopy were used to observe myelin injury and repair. Immunofluorescence staining was applied to observe the proliferation and differentiation of oligodendrocyte precursor cells (OPCs). Expression of key molecules were detected using immunofluorescence staining, quantitative real-time polymerase chain reaction, Western blotting, and Enzyme-linked immunosorbent assay, respectively. RESULTS PE exerted neuroprotective efects by modulating microglial state, promoting remyelination and recovery of neurological function of rats over 35 d after stroke, while silencing Trem2 expression in rats suppressed the aforementioned effects promoted by PE. In addition, by leveraging the activin-A neutralizing antibody, we found a direct beneficial effect of PE on microglia-derived activin-A and its subsequent role on oligodendrocyte differentiation and remyelination mediated by the activin-A/Acvr axis. CONCLUSIONS The present study reveals a novel regenerative role of PE in white matter injury after stroke, which is mediated by upregulation of TREM2 and microglia-derived factor for oligodendrocytes regeneration. PE is an effective therapeutic approach for improving white matter integrity and alleviating neurological function deficits after ischemic stroke.
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Affiliation(s)
- Jinghui Xu
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Liying Zhang
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Mingyue Li
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Xiaofei He
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Jing Luo
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Rui Wu
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Zhongqiu Hong
- grid.12981.330000 0001 2360 039XDepartment of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China
| | - Haiqing Zheng
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China.
| | - Xiquan Hu
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600 Tianhe Road, Guangzhou, China.
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Ruganzu JB, Peng X, He Y, Wu X, Zheng Q, Ding B, Lin C, Guo H, Yang Z, Zhang X, Yang W. Downregulation of TREM2 expression exacerbates neuroinflammatory responses through TLR4-mediated MAPK signaling pathway in a transgenic mouse model of Alzheimer's disease. Mol Immunol 2021; 142:22-36. [PMID: 34959070 DOI: 10.1016/j.molimm.2021.12.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 12/20/2022]
Abstract
Activation of glial cells and neuroinflammation play an important role in the onset and development of Alzheimer's disease (AD). Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglia-specific receptor in the brain that is involved in regulating neuroinflammation. However, the precise effects of TREM2 on neuroinflammatory responses and its underlying molecular mechanisms in AD have not been studied in detail. Here, we employed a lentiviral-mediated strategy to downregulation of TREM2 expression on microglia in the brain of APPswe/PS1dE9 (APP/PS1) transgenic mice and BV2 cells. Our results showed that downregulation of TREM2 significantly aggravated AD-related neuropathology including Aβ accumulation, peri-plaque microgliosis and astrocytosis, as well as neuronal and synapse-associated proteins loss, which was accompanied by a decline in cognitive ability. The further mechanistic study revealed that downregulation of TREM2 expression initiated neuroinflammatory responses through toll-like receptor 4 (TLR4)-mediated mitogen-activated protein kinase (MAPK) signaling pathway and subsequent stimulating the production of pro-inflammatory cytokines in vivo and in vitro. Moreover, blockade of p38, JNK, and ERK1/2 inhibited the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) induced by Aβ1-42 in TREM2-knocked down BV2 cells. Taken together, these findings indicated that TREM2 might be a potential therapeutic target for AD and other neuroinflammation-related diseases.
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Affiliation(s)
- John Bosco Ruganzu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Xiaoqian Peng
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Yingying He
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Xiangyuan Wu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Quzhao Zheng
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Bo Ding
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Chengheng Lin
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Hongsong Guo
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Zikang Yang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Xiao Zhang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Weina Yang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China.
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9
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Hu M, Lin Y, Men X, Wang S, Sun X, Zhu Q, Lu D, Liu S, Zhang B, Cai W, Lu Z. High-salt diet downregulates TREM2 expression and blunts efferocytosis of macrophages after acute ischemic stroke. J Neuroinflammation 2021; 18:90. [PMID: 33845849 PMCID: PMC8040220 DOI: 10.1186/s12974-021-02144-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/29/2021] [Indexed: 01/19/2023] Open
Abstract
Background A high-salt diet (HSD) is one of the major risk factors for acute ischemic stroke (AIS). As a potential mechanism, surplus salt intake primes macrophages towards a proinflammatory phenotype. In this study, whether HSD could blunt the efferocytic capability of macrophages after ischemic stroke, thus exacerbating post-stroke neural inflammation, was investigated. Methods Wild-type male C57BL/6 mice were fed with fodder containing 8% sodium chloride for 4 weeks and subjected to transient middle cerebral occlusion (tMCAO). Disease severity, macrophage polarization as well as efferocytic capability were evaluated. Bone marrow-derived macrophages were cultured in vitro, and the impact of high salinity on their efferocytic activity, as well as their expression of phagocytic molecules, were analyzed. The relationships among sodium concentration, macrophage phenotype, and disease severity in AIS patients were explored. Results HSD-fed mice displayed increased infarct volume and aggravated neurological deficiency. Mice fed with HSD suffered exacerbated neural inflammation as shown by higher inflammatory mediator expression and immune cell infiltration levels. Infiltrated macrophages within stroke lesions in HSD-fed mice exhibited a shift towards proinflammatory phenotype and impaired efferocytic capability. As assessed with a PCR array, the expression of triggering receptor expressed on myeloid cells 2 (TREM2), a receptor relevant to phagocytosis, was downregulated in high-salt-treated bone marrow-derived macrophages. Enhancement of TREM2 signaling restored the efferocytic capacity and cellular inflammation resolution of macrophages in a high salinity environment in vitro and in vivo. A high concentration of urine sodium in AIS patients was found to be correlated with lower TREM2 expression and detrimental stroke outcomes. Conclusions HSD inhibited the efferocytic capacity of macrophages by downregulating TREM2 expression, thus impeding inflammation resolution after ischemic stroke. Enhancing TREM2 signaling in monocytes/macrophages could be a promising therapeutic strategy to enhance efferocytosis and promote post-stroke inflammation resolution. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02144-9.
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Affiliation(s)
- Mengyan Hu
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Yinyao Lin
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Xuejiao Men
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Shisi Wang
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Xiaobo Sun
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Qiang Zhu
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Danli Lu
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Sanxin Liu
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Bingjun Zhang
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Wei Cai
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China. .,Center of Clinical Immunology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China.
| | - Zhengqi Lu
- Department of Neurology, Mental and Neurological Disease Research Center, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China.
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10
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Yu J, Shi YC, Ping F, Li W, Zhang HB, He SL, Zhao Y, Xu LL, Li YX. Liraglutide Inhibits Osteoclastogenesis and Improves Bone Loss by Downregulating Trem2 in Female Type 1 Diabetic Mice: Findings From Transcriptomics. Front Endocrinol (Lausanne) 2021; 12:763646. [PMID: 34975749 PMCID: PMC8715718 DOI: 10.3389/fendo.2021.763646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/08/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The mechanisms of bone fragility in type 1 diabetes (T1D) are not fully understood. Whether glucagon-like peptide-1 receptor (GLP-1R) agonists could improve bone quality in T1D context also remains elusive. AIMS We aimed to explore the possible mechanisms of bone loss in T1D and clarify whether liraglutide has effects on bone quality of T1D mice using transcriptomics. METHODS Female streptozotocin-induced diabetic C57BL/6J mice were randomly divided into four groups and received the following treatments daily for 8 weeks: saline as controls, insulin, liraglutide, and liraglutide combined with insulin. These groups were also compared with non-STZ-treated normal glucose tolerance (NGT) group. Trunk blood and bone tissues were collected for analysis. Three tibia from each of the NGT, saline-treated, and liraglutide-treated groups were randomly selected for transcriptomics. RESULTS Compared with NGT mice, saline-treated T1D mice manifested markedly hyperglycemia and weight loss, and micro-CT revealed significantly lower bone mineral density (BMD) and deficient microarchitectures in tibias. Eight weeks of treatment with liraglutide alone or combined with insulin rescued the decreased BMD and partly corrected the compromised trabecular microarchitectures. Transcriptomics analysis showed there were 789 differentially expressed genes mainly mapped to osteoclastogenesis and inflammation pathways. The RT-qPCR verified that the gene expression of Trem2, Nfatc1, Trap, and Ctsk were significantly increased in the tibia of T1D compared with those in the NGT group. Liraglutide treatment alone or combined with insulin could effectively suppress osteoclastogenesis by downregulating the gene expression of Trem2, Nfatc1, Ctsk, and Trap. CONCLUSIONS Taken together, increased osteoclastogenesis with upregulated expression of Trem2 played an important role in bone loss of T1D mice. Liraglutide provided protective effects on bone loss in T1D mice by suppressing osteoclastogenesis.
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Affiliation(s)
- Jie Yu
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yan-Chuan Shi
- Group of Neuroendocrinology, Diabetes and Metabolism Division, Garvan Institute of Medical Research, St Vincent’s Hospital, Sydney, NSW, Australia
- Faculty of Medicine, UNSW, Sydney, NSW, Australia
| | - Fan Ping
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Wei Li
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Hua-Bing Zhang
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shu-Li He
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yuan Zhao
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ling-Ling Xu
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- *Correspondence: Ling-Ling Xu, ; Yu-Xiu Li,
| | - Yu-Xiu Li
- Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- *Correspondence: Ling-Ling Xu, ; Yu-Xiu Li,
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11
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von Saucken VE, Jay TR, Landreth GE. The effect of amyloid on microglia-neuron interactions before plaque onset occurs independently of TREM2 in a mouse model of Alzheimer's disease. Neurobiol Dis 2020; 145:105072. [PMID: 32890775 PMCID: PMC7808254 DOI: 10.1016/j.nbd.2020.105072] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/13/2020] [Accepted: 08/30/2020] [Indexed: 12/23/2022] Open
Abstract
Genetic studies identified mutations in several immune-related genes that confer increased risk for developing Alzheimer’s disease (AD), suggesting a key role for microglia in AD pathology. Microglia are recruited to and actively modulate the local toxicity of amyloid plaques in models of AD through these cells’ transcriptional and functional reprogramming to a disease-associated phenotype. However, it remains unknown whether microglia actively respond to amyloid accumulation before plaque deposition in AD. We compared microglial interactions with neurons that exhibit amyloid accumulation to those that do not in 1-month-old 5XFAD mice to determine which aspects of microglial morphology and function are altered by early 6E10+ amyloid accumulation. We provide evidence of preferential microglial process engagement of amyloid laden neurons. Microglia, on exposure to amyloid, also increase their internalization of neurites even before plaque onset. Unexpectedly, we found that triggering receptor expressed on myeloid cells 2 (TREM2), which is critical for microglial responses to amyloid plaque pathology later in disease, is not required for enhanced microglial interactions with neurons or neurite internalization early in disease. However, TREM2 was still required for early morphological changes exhibited by microglia. These data demonstrate that microglia sense and respond to amyloid accumulation before plaques form using a distinct mechanism from the TREM2-dependent pathway required later in disease.
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Affiliation(s)
- Victoria E von Saucken
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Taylor R Jay
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gary E Landreth
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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12
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Yang J, Fu Z, Zhang X, Xiong M, Meng L, Zhang Z. TREM2 ectodomain and its soluble form in Alzheimer's disease. J Neuroinflammation 2020; 17:204. [PMID: 32635934 PMCID: PMC7341574 DOI: 10.1186/s12974-020-01878-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a receptor mainly expressed on the surface of microglia. It mediates multiple pathophysiological processes in various diseases. Recently, TREM2 has been found to play a role in the development of Alzheimer's disease (AD). TREM2 is a transmembrane protein that is specifically expressed on microglia in the brain. It contains a long ectodomain that directly interacts with the extracellular environment to regulate microglial function. The ectodomain of TREM2 is processed by a disintegrin and metalloprotease, resulting in the release of a soluble form of TREM2 (sTREM2). Recent studies have demonstrated that sTREM2 is a bioactive molecule capable of binding ligands, activating microglia, and regulating immune responses during the AD continuum. Clinical studies revealed that sTREM2 level is elevated in cerebrospinal fluid (CSF) of AD patients, and the sTREM2 level is positively correlated with the levels of classical CSF biomarkers, namely t-tau and p-tau, indicating that it is a reliable predictor of the early stages of AD. Herein, we summarize the key results on the generation, structure, and function of sTREM2 to provide new insights into TREM2-related mechanisms underlying AD pathogenesis and to promote the development of TREM2-based therapeutic strategy.
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Affiliation(s)
- Jiaolong Yang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhihui Fu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Xingyu Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Min Xiong
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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13
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Niu W, Ma L, Tao T, Tian F, He T, Qiao M, He H, Liu X, Zhao X. Surgery-induced cognitive dysfunction is alleviated through triggering receptor expressed on myeloid cells 2. Acta Histochem 2020; 122:151553. [PMID: 32381365 DOI: 10.1016/j.acthis.2020.151553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 01/22/2023]
Abstract
Neuroinflammation plays a key role in perioperative neurocognitive disorders (PND). Increased evidences indicate that triggering receptor expressed on myeloid cells 2 (TREM2) can mitigate inflammatory response in the brain, and the aim of this study is to investigate whether TREM2 is involved in surgery-induced cognitive dysfunction in adult mice. We used adult C57BL/6 mice subjected to intramedullary fixation surgery, and found that surgery did not impair the motor ability of mice, but worsened the learning and memory function, and reduced the expression of TREM2. Meanwhile, up-regulated TREM2 expression in the brain of mice, induced by selective TREM2 agonist HSP60, significantly improved the learning and memory, alleviated the neuroinflammation, and decreased the neuronal cell apoptosis in mice. Meanwhile, TREM2-siRNA abolished the increased expression of TREM2 induced by HSP60, and reversed all the HSP60-induced beneficial effects. Therefore, our study indicated that up-regulation of TREM2 alleviated neuroinflammation and improved learning and memory function after surgery in mice.
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Affiliation(s)
- Wen Niu
- Department of Pathophysiology, Institute of Basic Medical Science, PLA General Hospital, Beijing, 100853, China; Department of Physiology and Pathophysiology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Lei Ma
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Tianqi Tao
- Department of Pathophysiology, Institute of Basic Medical Science, PLA General Hospital, Beijing, 100853, China
| | - Fangfang Tian
- Department of Anesthesiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Tao He
- Department of Pathophysiology, Institute of Basic Medical Science, PLA General Hospital, Beijing, 100853, China
| | - Min Qiao
- Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Haimeng He
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Xiuhua Liu
- Department of Pathophysiology, Institute of Basic Medical Science, PLA General Hospital, Beijing, 100853, China.
| | - Xiayong Zhao
- Department of Physiology and Pathophysiology, The Fourth Military Medical University, Xi'an, 710032, China; Department of Anesthesiology, Ankang Central Hospital, Ankang, 725000, China.
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14
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Zhang Y, Feng S, Nie K, Li Y, Gao Y, Gan R, Wang L, Li B, Sun X, Wang L, Zhang Y. TREM2 modulates microglia phenotypes in the neuroinflammation of Parkinson's disease. Biochem Biophys Res Commun 2018; 499:797-802. [PMID: 29621548 DOI: 10.1016/j.bbrc.2018.03.226] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 03/31/2018] [Indexed: 11/19/2022]
Abstract
Neuroinflammation and overactivated microglia underlies the pathogenesis of Parkinson's disease (PD). Furthermore, microglia could polarize into classic inflammatory M1 and immunosuppressive M2 phenotype. Thus, inhibiting the overactivated inflammatory M1 microglia by promoting the transformation of microglia to the protective M2 phenotype provides potential therapy for PD, but the mechanism that modulates microglia polarization remains unknown. Triggering receptor expressed on myeloid cells-2 (TREM2) is a recently identified immune receptor expressed by the microglia in the brain. Emerging evidence indicates that TREM2 enhances the phagocytosis function of microglia and suppress inflammation. Based on these evidence, we hypothesized that TREM2 might play a protective role through regulating microglia polarization. Here, we employ a lentiviral strategy to overexpress or suppress TREM2 on microglia and found that TREM2 was essential for M2 microglia polarization. Knockdown of TREM2 in BV2 microglia inhibited M2 polarization and lead to exaggeration of M1 microglial inflammatory responses, whereas overexpression of TREM2 promoted M2 polarization and alleviated microglial inflammation. We also observed that the TREM2 level was higher in the midbrain of PD mice, which was accompanied by an elevated level of Arginase-1 and increased proinflammatory cytokines, suggesting that TREM2 is an important factor in switching the microglia phenotypes. Taken together, these findings indicate that TREM2 plays a crucial role in altering the proinflammatory M1 microglia to M2 phenotype and has beneficial effects in the immune pathogenesis of PD.
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Affiliation(s)
- Youwen Zhang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China; Department of Neurology, The People's Hospital of Gaozhou, Guangdong, China
| | - Shujun Feng
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Kun Nie
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yan Li
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yuyuan Gao
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Rong Gan
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Limin Wang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Bing Li
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xuegang Sun
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Lijuan Wang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Yuhu Zhang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
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15
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Abstract
TREM2 variants have been identified as risk factors for Alzheimer’s disease (AD) and other neurodegenerative diseases (NDDs). Because TREM2 encodes a receptor exclusively expressed on immune cells, identification of these variants conclusively demonstrates that the immune response can play an active role in the pathogenesis of NDDs. These TREM2 variants also confer the highest risk for developing Alzheimer’s disease of any risk factor identified in nearly two decades, suggesting that understanding more about TREM2 function could provide key insights into NDD pathology and provide avenues for novel immune-related NDD biomarkers and therapeutics. The expression, signaling and function of TREM2 in NDDs have been extensively investigated in an effort to understand the role of immune function in disease pathogenesis and progression. We provide a comprehensive review of our current understanding of TREM2 biology, including new insights into the regulation of TREM2 expression, and TREM2 signaling and function across NDDs. While many open questions remain, the current body of literature provides clarity on several issues. While it is still often cited that TREM2 expression is decreased by pro-inflammatory stimuli, it is now clear that this is true in vitro, but inflammatory stimuli in vivo almost universally increase TREM2 expression. Likewise, while TREM2 function is classically described as promoting an anti-inflammatory phenotype, more than half of published studies demonstrate a pro-inflammatory role for TREM2, suggesting that its role in inflammation is much more complex. Finally, these components of TREM2 biology are applied to a discussion of how TREM2 impacts NDD pathologies and the latest assessment of how these findings might be applied to immune-directed clinical biomarkers and therapeutics.
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Affiliation(s)
- Taylor R Jay
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Victoria E von Saucken
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN, 46202, USA
| | - Gary E Landreth
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH, 44106, USA. .,Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN, 46202, USA.
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16
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Belloli S, Pannese M, Buonsanti C, Maiorino C, Di Grigoli G, Carpinelli A, Monterisi C, Moresco RM, Panina-Bordignon P. Early upregulation of 18-kDa translocator protein in response to acute neurodegenerative damage in TREM2-deficient mice. Neurobiol Aging 2017; 53:159-168. [PMID: 28189343 DOI: 10.1016/j.neurobiolaging.2017.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/21/2016] [Accepted: 01/06/2017] [Indexed: 10/20/2022]
Abstract
Mutations in the TREM2 gene confer risk for Alzheimer's disease and susceptibility for Parkinson's disease (PD). We evaluated the effect of TREM2 deletion in a 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model, measuring neurodegeneration and microglia activation using a combined in vivo imaging and postmortem molecular approach. In wild-type mice, MPTP administration induced a progressive decrease of [11C]FECIT uptake, culminating at day 7. Neuronal loss was accompanied by an increase of TREM2, IL-1β, and translocator protein (TSPO) transcript levels, [11C]PK11195 binding and GFAP staining (from day 2), and an early and transient increase of TNF-α, Galectin-3, and Iba-1 (from day 1). In TREM2 null (TREM2-/-) mice, MPTP similarly affected neuron viability and microglial cells, as shown by the lower level of Iba-1 staining in basal condition, and reduced increment of Iba-1, TNF-α, and IL-1β in response to MPTP. Likely to compensate for TREM2 absence, TREM2-/- mice showed an earlier increment of [11C]PK11195 binding and a significant increase of IL-4. Taken together, our data demonstrate a central role of TREM2 in the regulation of microglia response to acute neurotoxic insults and suggest a potential modulatory role of TSPO in response to immune system deficit.
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Affiliation(s)
- Sara Belloli
- Institute of Bioimages and Molecular Physiology, National Research Council, Segrate, MI, Italy; Milan Center for Neuroscience (NeuroMi), Milan, Italy; Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Pannese
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Cecilia Buonsanti
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Chiara Maiorino
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giuseppe Di Grigoli
- Institute of Bioimages and Molecular Physiology, National Research Council, Segrate, MI, Italy; Milan Center for Neuroscience (NeuroMi), Milan, Italy
| | - Assunta Carpinelli
- Institute of Bioimages and Molecular Physiology, National Research Council, Segrate, MI, Italy
| | - Cristina Monterisi
- Department of Medicine and Surgery, University of Milan Bicocca, Monza, Italy
| | - Rosa Maria Moresco
- Milan Center for Neuroscience (NeuroMi), Milan, Italy; Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy; Department of Medicine and Surgery, University of Milan Bicocca, Monza, Italy.
| | - Paola Panina-Bordignon
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
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