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Bharadwaj S, Groza Y, Mierzwicka JM, Malý P. Current understanding on TREM-2 molecular biology and physiopathological functions. Int Immunopharmacol 2024; 134:112042. [PMID: 38703564 DOI: 10.1016/j.intimp.2024.112042] [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: 02/08/2024] [Revised: 04/05/2024] [Accepted: 04/05/2024] [Indexed: 05/06/2024]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM-2), a glycosylated receptor belonging to the immunoglobin superfamily and especially expressed in the myeloid cell lineage, is frequently explained as a reminiscent receptor for both adaptive and innate immunity regulation. TREM-2 is also acknowledged to influence NK cell differentiation via the PI3K and PLCγ signaling pathways, as well as the partial activation or direct inhibition of T cells. Additionally, TREM-2 overexpression is substantially linked to cell-specific functions, such as enhanced phagocytosis, reduced toll-like receptor (TLR)-mediated inflammatory cytokine production, increased transcription of anti-inflammatory cytokines, and reshaped T cell function. Whereas TREM-2-deficient cells exhibit diminished phagocytic function and enhanced proinflammatory cytokines production, proceeding to inflammatory injuries and an immunosuppressive environment for disease progression. Despite the growing literature supporting TREM-2+ cells in various diseases, such as neurodegenerative disorders and cancer, substantial facets of TREM-2-mediated signaling remain inadequately understood relevant to pathophysiology conditions. In this direction, herein, we have summarized the current knowledge on TREM-2 biology and cell-specific TREM-2 expression, particularly in the modulation of pivotal TREM-2-dependent functions under physiopathological conditions. Furthermore, molecular regulation and generic biological relevance of TREM-2 are also discussed, which might provide an alternative approach for preventing or reducing TREM-2-associated deformities. At last, we discussed the TREM-2 function in supporting an immunosuppressive cancer environment and as a potential drug target for cancer immunotherapy. Hence, summarized knowledge of TREM-2 might provide a window to overcome challenges in clinically effective therapies for TREM-2-induced diseases in humans.
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Affiliation(s)
- Shiv Bharadwaj
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic.
| | - Yaroslava Groza
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Joanna M Mierzwicka
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Petr Malý
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic.
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2
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Matos ADO, Dantas PHDS, Queiroz HAGDB, Silva-Sales M, Sales-Campos H. TREM-2: friend or foe in infectious diseases? Crit Rev Microbiol 2024; 50:1-19. [PMID: 36403150 DOI: 10.1080/1040841x.2022.2146481] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/07/2022] [Indexed: 11/21/2022]
Abstract
The triggering receptor expressed on myeloid cells-2 (TREM-2) is an immune receptor expressed on immune and non-immune cells, more frequently investigated in neurodegenerative disorders and considered a marker for microglia activation. In infectious diseases, the receptor was initially believed to be an anti-inflammatory molecule, opposing the inflammation triggered by TREM-1. Currently, TREM-2 is associated with different aspects in response to infectious stimuli, including the induction of bacterial phagocytosis and clearance, containment of exacerbated pro-inflammatory responses, induction of M2 differentiation and activation of Th1 lymphocytes, besides of neurological damage after viral infection. Here, we present and discuss results published in the last two decades regarding the expression, activation and functions of TREM-2 during the course of bacterial, viral, fungal and parasitic infections. A surprisingly plasticity was observed regarding the roles of the receptor in the aforementioned contexts, which largely varied according to the cell/organ and pathogen type, besides influencing disease outcome. Therefore, our review aimed to critically overview the role of TREM-2 in infectious diseases, highlighting its potential to be used as a clinical biomarker or therapeutic target.
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Affiliation(s)
| | | | | | - Marcelle Silva-Sales
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Brazil
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3
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Zhong HL, Li PZ, Li D, Guan CX, Zhou Y. The role of vasoactive intestinal peptide in pulmonary diseases. Life Sci 2023; 332:122121. [PMID: 37742737 DOI: 10.1016/j.lfs.2023.122121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 09/12/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
Vasoactive intestinal peptide (VIP) is an abundant neurotransmitter in the lungs and other organs. Its discovery dates back to 1970. And VIP gains attention again due to the potential application in COVID-19 after a research wave in the 1980s and 1990s. The diverse biological impacts of VIP extend beyond its usage in COVID-19 treatment, encompassing its involvement in various pulmonary and systemic disorders. This review centers on the function of VIP in various lung diseases, such as pulmonary arterial hypertension, chronic obstructive pulmonary disease, asthma, cystic fibrosis, acute lung injury/acute respiratory distress syndrome, pulmonary fibrosis, and lung tumors. This review also outlines two main limitations of VIP as a potential medication and gathers information on extended-release formulations and VIP analogues.
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Affiliation(s)
- Hong-Lin Zhong
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Pei-Ze Li
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Di Li
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Cha-Xiang Guan
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| | - Yong Zhou
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
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4
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Fan R, Cheng Z, Huang Z, Yang Y, Sun N, Hu B, Hou P, Liu B, Huang C, Liu S. TREM-1, TREM-2 and their association with disease severity in patients with COVID-19. Ann Med 2023; 55:2269558. [PMID: 37848000 PMCID: PMC10583614 DOI: 10.1080/07853890.2023.2269558] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/28/2023] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND Delayed diagnosis and inadequate treatment caused by limited biomarkers are associated with the outcomes of COVID-19 patients. It is necessary to identify other promising biomarkers and candidate targets for defining dysregulated inflammatory states. METHODS The triggering receptors expressed on myeloid cell (TREM)-1 and TREM-2 expression from hospitalized COVID-19 patients were characterized using ELISA and flow cytometry, respectively. Their correlation with disease severity and contrast with the main clinical indicators were evaluated. RESULTS Increased expression of soluble TREM-1 and TREM-2 in the plasma of COVID-19 patients was found compared to the control group. Moreover, membrane-bound TREM-1 and TREM-2 expression was upregulated on the cell surface of circulating blood T cells from COVID-19 patients. Correlation analysis showed that sTREM-2 levels were negatively correlated with PaO2/FiO2, but positively correlated with C-reactive protein (CRP), procalcitonin (PCT) and interleukin (IL)-6 levels. Receiver operating characteristic curve analysis indicated that the predictive efficacy of sTREM-1 and sTREM-2 was equivalent to CRP and IL-6, and a little better than absolute leukocyte or neutrophil count and PCT in distinguishing disease severity. CONCLUSION TREM-2 and TREM-1 are critical host immune factors that response to SARS-COV-2 infection and could serve as potential diagnostic biomarkers and therapeutic targets for COVID-19.
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Affiliation(s)
- Ruyue Fan
- Shandong Center for Disease Control and Prevention, Jinan, China
| | - Zuowang Cheng
- Department of Clinical Laboratory, Zhangqiu District People’s Hospital Affiliated to Jining Medical University, Jinan, China
| | - Zhisheng Huang
- Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
- Department of Pulmonary and Critical Care Medicine, National Regional Center for Respiratory Medicine, Jiangxi Hospital of China-Japan Friendship Hospital, Nanchang, China
| | - Ying Yang
- Shandong Center for Disease Control and Prevention, Jinan, China
| | - Na Sun
- Shandong Center for Disease Control and Prevention, Jinan, China
| | - Bin Hu
- Shandong Center for Disease Control and Prevention, Jinan, China
| | - Peibin Hou
- Shandong Center for Disease Control and Prevention, Jinan, China
| | - Bo Liu
- Department of Pulmonary and Critical Care Medicine, Zibo Municipal Hospital, Zibo, China
| | - Chuanjun Huang
- Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Shuai Liu
- Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
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Cao Y, Wang Y, Peng N, Xiao J, Wang S, Fu C. The ratio of urinary TREM-1/TREM-2 mRNA expression in chronic kidney disease and renal fibrosis. Ann Med 2021; 53:1010-1018. [PMID: 34176389 PMCID: PMC8245072 DOI: 10.1080/07853890.2021.1912384] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The non-invasive identification of novel renal fibrosis biomarkers needs to be further studied. METHODS We collected urine samples from 77 biopsy-proven CKD patients and 15 healthy controls. The expression of urinary TREM-1 and TREM-2 was measured and the correlation with renal function parameter and pathological indicators was performed. The receiver operating characteristic (ROC) curve for the diagnosis of renal fibrosis was calculated. The protein expression of TREM-1 and TREM-2 in kidney tissues was measured. RESULTS The TREM-1/TREM-2 ratio was decreased in CKD patients and correlated with serum creatinine, estimated glomerular filtration rate and cystatin c. Further, the TREM-1/TREM-2 ratio was significantly decreased in moderate-severe fibrosis patients compared with none-mild renal fibrosis. TREM-1/TREM-2 ratio was correlated with the score of tubulointerstitial fibrosis (TIF) and the score of glomerular sclerosis. The ROC curve showed that the urinary TREM-1/TREM-2 ratio can diagnosemoderate-severe renal fibrosis at a cut-off value of 1.338 with a sensitivity of 86.4% and specificity of 81.8%. In human moderate-severe fibrosis kidney tissue, the protein expression of TREM-1 was lower and the TREM-2 was higher than none-mild fibrosis kidney tissue. CONCLUSION Urinary TREM-1/TREM-2 ratio was a potential biomarker for the diagnosis of renal fibrosis in CKD patients.
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Affiliation(s)
- Yuhan Cao
- Department of Nephrology, Yi Ji Shan Hospital Affiliated to Wan Nan Medical College, China.,Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (Wann Nan Medical College), China
| | - Yuwei Wang
- Department of Nephrology, Yi Ji Shan Hospital Affiliated to Wan Nan Medical College, China
| | - Nana Peng
- School of Clinical Medicine, Wan Nan Medical College, China
| | - Jie Xiao
- School of Anesthesiology, Wan Nan Medical College, China
| | - Sufen Wang
- Department of Pathology, Yi Ji Shan hospital affiliated to Wan Nan Medical College, China
| | - Cong Fu
- Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (Wann Nan Medical College), China.,Department of Cardiology, Yi Ji Shan hospital affiliated to Wan Nan Medical College, China
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Duan JX, Guan XX, Yang HH, Mei WX, Chen P, Tao JH, Li Q, Zhou Y. Vasoactive intestinal peptide attenuates bleomycin-induced murine pulmonary fibrosis by inhibiting epithelial-mesenchymal transition: Restoring autophagy in alveolar epithelial cells. Int Immunopharmacol 2021; 101:108211. [PMID: 34634687 DOI: 10.1016/j.intimp.2021.108211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/13/2021] [Accepted: 09/28/2021] [Indexed: 12/19/2022]
Abstract
Vasoactive intestinal peptide (VIP) is an intrapulmonary neuropeptide with multi-function, including anti-fibrosis. However, the exact role of VIP in pulmonary fibrosis has not been documented. Here, we investigated the protective effect of VIP against pulmonary fibrosis in a murine model induced by bleomycin (BLM). We found that the overexpression of VIP mediated by the adenoviral vector significantly attenuated the lung tissue destruction, reduced the deposition of the extracellular matrix, and inhibited the expression of alpha-smooth muscle actin (α-SMA) in the lungs of mice received BLM. Mechanismly, we found that VIP significantly suppressed the transforming growth factor-beta 1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) and inhibited the matrix-producing ability of alveolar epithelial cells in vitro. Furthermore, we found that TGF-β1 depressed the autophagy and an autophagy inductor partly reversed the TGF-β1-induced EMT in alveolar epithelial cells. The impaired autophagy was also observed in the lungs of BLM-treated mice, which was restored by VIP treatment. And VIP treatment enhanced autophagy in TGF-β1-stimulated alveolar epithelial cells, contributing to its anti-EMT effect. In summary, our data, for the first time, show that VIP attenuates BLM-induced pulmonary fibrosis in mice with anti-EMT effect through restoring autophagy in alveolar epithelial cells. This study provides a possibility that inhaled long-acting VIP may be an anti-fibrotic drug in the treatment of pulmonary fibrosis.
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Affiliation(s)
- Jia-Xi Duan
- Department of Pulmonary and Critical Care Medicine, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; Research Unit of Respiratory Disease, Central South University, Changsha, Hunan 410011, China
| | - Xin-Xin Guan
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Hui-Hui Yang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Wen-Xiu Mei
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Ping Chen
- Department of Pulmonary and Critical Care Medicine, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; Research Unit of Respiratory Disease, Central South University, Changsha, Hunan 410011, China
| | - Jia-Hao Tao
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Qing Li
- Department of Physiology, Hunan University of Medicine, Huaihua, Hunan 418000, China
| | - Yong Zhou
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
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7
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Activation of TREM-1 induces endoplasmic reticulum stress through IRE-1α/XBP-1s pathway in murine macrophages. Mol Immunol 2021; 135:294-303. [PMID: 33957479 DOI: 10.1016/j.molimm.2021.04.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 04/16/2021] [Accepted: 04/26/2021] [Indexed: 12/14/2022]
Abstract
Increasing evidence suggests that endoplasmic reticulum (ER) stress activates several pro-inflammatory signaling pathways in many diseases, including acute lung injury (ALI). We have reported that blocking triggering receptor expressed on myeloid cells 1 (TREM-1) protects against ALI by suppressing pulmonary inflammation in mice with ALI induced by lipopolysaccharides (LPS). However, the molecular mechanism underlying the TREM-1-induced pro-inflammatory microenvironment in macrophages remains unclearly. Herein, we aimed to determine whether TREM-1 regulates the inflammatory responses induced by LPS associated with ER stress activation. We found that the activation of TREM-1 by a monoclonal agonist antibody (anti-TREM-1) increased the mRNA and protein levels of IL-1β, TNF-α, and IL-6 in primary macrophages. Treatment of the anti-TREM-1 antibody increased the expression of ER stress markers (ATF6, PERK, IRE-1α, and XBP-1s) in primary macrophages. While pretreatment with 4-PBA, an inhibitor of ER stress, significantly inhibited the expression of ER stress markers and pro-inflammatory cytokines and reduced LDH release. Furthermore, inhibiting the activity of the IRE-1α/XBP-1s pathway by STF-083010 significantly mitigated the increased levels of IL-1β, TNF-α, and IL-6 in macrophages treated by the anti-TREM-1 antibody. XBP-1 silencing attenuated pro-inflammatory microenvironment evoked by activation of TREM-1. Besides, we found that blockade of TREM-1 with LR12 ameliorated ER stress induced by LPS in vitro and in vivo. In conclusion, we conclude that TREM-1 activation induces ER stress through the IRE-1α/XBP-1s pathway in macrophages, contributing to the pro-inflammatory microenvironment.
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8
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Dantas PHDS, Matos ADO, da Silva Filho E, Silva-Sales M, Sales-Campos H. Triggering receptor expressed on myeloid cells-1 (TREM-1) as a therapeutic target in infectious and noninfectious disease: a critical review. Int Rev Immunol 2020; 39:188-202. [PMID: 32379561 DOI: 10.1080/08830185.2020.1762597] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The triggering receptor expressed on myeloid cells-1 (TREM-1) is an innate immune receptor found in the surface of several immune and non-immune cells. Since its first description in 2000, this molecule and its soluble form (sTREM-1) have been implicated in many diseases with infectious and noninfectious origins. As an amplifier of inflammation, the membrane-associated TREM-1 (mTREM-1) isoform induces the production of pro-inflammatory mediators, thus contributing to the pathogenesis of diseases such as sepsis, arthritis, colitis and infections. In this context, many studies have used molecules capable of inhibiting TREM-1 activity as anti-inflammatory drugs. In this regard, a few peptides have been showing promising results in the amelioration of detrimental immune responses. Some commercially available drugs, including corticosteroids and antibiotics, with known anti-inflammatory effects, have also shown activity in TREM-1 signaling. Therefore, considering the potential of this receptor as a therapeutic target, the present review encompasses the main compounds explored so far in TREM-1 modulation, highlighting and critically discussing its effects and major drawbacks of such approaches.
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Affiliation(s)
| | - Amanda de Oliveira Matos
- Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiânia, Goiás, Brazil
| | - Ernandes da Silva Filho
- Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiânia, Goiás, Brazil
| | - Marcelle Silva-Sales
- Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiânia, Goiás, Brazil
| | - Helioswilton Sales-Campos
- Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiânia, Goiás, Brazil
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Zhou Y, Zhang CY, Duan JX, Li Q, Yang HH, Sun CC, Zhang J, Luo XQ, Liu SK. Vasoactive intestinal peptide suppresses the NLRP3 inflammasome activation in lipopolysaccharide-induced acute lung injury mice and macrophages. Biomed Pharmacother 2020; 121:109596. [DOI: 10.1016/j.biopha.2019.109596] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/17/2019] [Accepted: 10/26/2019] [Indexed: 02/07/2023] Open
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10
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Zhang YF, Zhang J, Sun CC, Tang CY, Sun GY, Luo WJ, Zhou Y, Guan CX. Vasoactive intestinal peptide inhibits the activation of murine fibroblasts and expression of interleukin 17 receptor C. Cell Biol Int 2019; 43:770-780. [PMID: 31026365 DOI: 10.1002/cbin.11151] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/01/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is an acute, severe, and refractory pulmonary inflammation with high morbidity and mortality. Excessive activation of fibroblast during the fibroproliferative phase plays a pivotal role in the prognosis of ARDS. Our previous study demonstrated that the vasoactive intestinal peptide (VIP) is mediated by lentivirus attenuates lipopolysaccharide (LPS)-induced ARDS in a murine model, and VIP inhibits the release of interleukin-17A (IL-17A) from activation macrophages. However, the effects of VIP on the activation of murine fibroblast and expression of IL-17 receptor (IL-17R) in ARDS remain unclear. Here, a mouse model of ARDS was established by an intratracheal injection of LPS. We found that the gene expression of col3a1 and hydroxyproline contents in the lungs were significantly increased 24 h after LPS injection. IL-17RC rather than IL-17RA was increased in the lungs of mice with ARDS. In vitro, LPS activated NIH3T3 cells, which was suppressed by VIP in a dose-dependent manner. In detail, VIP reduced the hydroxyproline content and col3a1 messenger RNA induced by LPS in NIH3T3 cells, as well as the expression of α-smooth muscle actin. Furthermore, we found that VIP inhibited the expression of IL-17R in the lungs of mice with ARDS and NIH3T3 cells stimulated with LPS, which was partly inhibited by antagonists of protein kinase A and protein kinase C. Taken together, our results demonstrated that VIP inhibited the activation of fibroblast via downregulation of IL-17RC, which may contribute to the protective effects of VIP against ARDS in mice.
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Affiliation(s)
- Yan-Feng Zhang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China.,Department of Cardiovascular Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jun Zhang
- Department of Physiology, Hunan University of Medicine, Huaihua, Hunan, China
| | - Chen-Chen Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Chun-Yan Tang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Guo-Ying Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Wan-Jun Luo
- Department of Cardiovascular Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China
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TREM2 acts as a tumor suppressor in hepatocellular carcinoma by targeting the PI3K/Akt/β-catenin pathway. Oncogenesis 2019; 8:9. [PMID: 30683932 PMCID: PMC6350080 DOI: 10.1038/s41389-018-0115-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 12/03/2018] [Accepted: 12/20/2018] [Indexed: 12/13/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is involved in nonmalignant pathological processes. However, TREM2’s function in malignant diseases, especially in hepatocellular carcinoma (HCC) remains unknown. In the present study, we report that TREM2 is a novel tumor suppressor in HCC. TREM2 expression was obviously decreased in hepatoma cells (especially metastatic HCC cells), and in most human HCC tissues (especially extrahepatic metastatic tumors). Reduced tumor TREM2 expression was correlated with poor prognosis of HCC patients, and with aggressive pathological features (BCLC stage, tumor size, tumor encapsulation, vascular invasion, and tumor differentiation). TREM2 knockdown substantially promoted cell growth, migration, and invasion in vitro and in vivo, while TREM2 overexpression produced the opposite effect. TREM2 suppressed HCC metastasis by inhibiting epithelial-mesenchymal transition, accompanied by abnormal expression of epithelial and mesenchymal markers. Further study revealed that downregulation of TREM2 in HCC was regulated by miR-31-5p. Moreover, by directly interacting with β-catenin, TREM2 attenuated oncogenic and metastatic behaviors by inhibiting Akt and GSK3β phosphorylation, and activating β-catenin. TREM2 suppressed carcinogenesis and metastasis in HCC by targeting the PI3K/Akt/β-catenin pathway. Thus, we propose that TREM2 may be a candidate prognostic biomarker in malignant diseases and TREM2 restoration might be a prospective strategy for HCC therapy.
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12
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Omentin-1 protects against bleomycin-induced acute lung injury. Mol Immunol 2018; 103:96-105. [DOI: 10.1016/j.molimm.2018.09.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 09/05/2018] [Accepted: 09/09/2018] [Indexed: 12/12/2022]
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13
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Sun GY, Yang HH, Guan XX, Zhong WJ, Liu YP, Du MY, Luo XQ, Zhou Y, Guan CX. Vasoactive intestinal peptide overexpression mediated by lentivirus attenuates lipopolysaccharide-induced acute lung injury in mice by inhibiting inflammation. Mol Immunol 2018; 97:8-15. [PMID: 29544087 DOI: 10.1016/j.molimm.2018.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 02/01/2018] [Accepted: 03/05/2018] [Indexed: 01/17/2023]
Abstract
Vasoactive intestinal peptide (VIP) is one of the most abundant neuropeptides in the lungs with various biological characters. We have reported that VIP inhibited the expressions of TREM-1 and IL-17A, which are involved in the initiation and amplification of inflammation in acute lung injury (ALI). However, the overall effect of VIP on ALI remains unknown. The aim of this study is to investigate the therapeutic effect of VIP mediated by lentivirus (Lenti-VIP) on lipopolysaccharide (LPS)-induced murine ALI. We found that the expression of intrapulmonary VIP peaked at day7 after the intratracheal injection of Lenti-VIP. Lenti-VIP increased the respiratory rate, lung compliance, and tidal volume, while decreased airway resistance in ALI mice, detected by Buxco system. Lenti-VIP significantly reduced inflammatory cell infiltration and maintained the integrity of the alveolar septa. Lenti-VIP also remarkably decreased the total protein level, the number of neutrophil and lactate dehydrogenase activity in the bronchoalveolar lavage fluid of LPS-induced ALI mice. In addition, Lenti-VIP down-regulated pro-inflammatory tumor necrosis factor (TNF)-α mRNA and protein expression, while up-regulated anti-inflammatory interleukin-10 mRNA and protein expression in lungs of ALI mice. Furthermore, we observed that VIP reduced the TNF-α expression in murine macrophages under LPS stimulation through protein kinase C and protein kinase A pathways. Together, our findings show that in vivo administration of lentivirus expressing VIP exerts a potent therapeutic effect on LPS-induced ALI in mice via inhibiting inflammation.
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Affiliation(s)
- Guo-Ying Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China; School of Medicine, Hunan Normal University, Changsha, Hunan 410013, China
| | - Hui-Hui Yang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Xin-Xin Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Wen-Jing Zhong
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Yong-Ping Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Ming-Yuan Du
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Xiao-Qin Luo
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China.
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China.
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Duan JX, Zhou Y, Zhou AY, Guan XX, Liu T, Yang HH, Xie H, Chen P. Calcitonin gene-related peptide exerts anti-inflammatory property through regulating murine macrophages polarization in vitro. Mol Immunol 2017; 91:105-113. [DOI: 10.1016/j.molimm.2017.08.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/04/2017] [Accepted: 08/22/2017] [Indexed: 01/10/2023]
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15
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Jay TR, von Saucken VE, Landreth GE. TREM2 in Neurodegenerative Diseases. Mol Neurodegener 2017; 12:56. [PMID: 28768545 PMCID: PMC5541421 DOI: 10.1186/s13024-017-0197-5] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/20/2017] [Indexed: 12/12/2022] Open
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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Dong L, Zhou Y, Zhu ZQ, Liu T, Duan JX, Zhang J, Li P, Hammcok BD, Guan CX. Soluble Epoxide Hydrolase Inhibitor Suppresses the Expression of Triggering Receptor Expressed on Myeloid Cells-1 by Inhibiting NF-kB Activation in Murine Macrophage. Inflammation 2017; 40:13-20. [PMID: 27696333 DOI: 10.1007/s10753-016-0448-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Triggering receptors expressed on myeloid cell-1 (TREM-1) is a superimmunoglobulin receptor expressed on myeloid cells. TREM-1 amplifies the inflammatory response. Epoxyeicosatrienoic acids (EETs), the metabolites of arachidonic acid derived from the cytochrome P450 enzyme, have anti-inflammatory properties. However, the effects of EETs on TREM-1 expression under inflammatory stimulation remain unclear. Therefore, inhibition of soluble epoxide hydrolase (sEH) with a highly selective inhibitor [1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea, TPPU] was used to stabilize EETs. LPS was intratracheally injected into mice to induce pulmonary inflammation, after TPPU treatment for 3 h. Histological examination showed TPPU treatment-alleviated LPS-induced pulmonary inflammation. TPPU decreased TREM-1 expression, but not DAP12 or MyD88 expression. Murine peritoneal macrophages were challenged with LPS in vitro. We found that TPPU reduced LPS-induced TREM-1 expression in a dose-dependent manner, but not DAP12 or MyD88 expression. TPPU also decreased downstream signal from TREM-1, reducing pro-inflammatory cytokine TNF-α and IL-1β mRNA expression. Furthermore, TPPU treatment inhibited IkB degradation in vivo and in vitro. Our results indicate that the inhibition of sEH suppresses LPS-induced TREM-1 expression and inflammation via inhibiting NF-kB activation in murine macrophage.
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Affiliation(s)
- Liang Dong
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, 56300, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China
| | - Zhao-Qiong Zhu
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, 56300, China
| | - Tian Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China
| | - Jia-Xi Duan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China
| | - Jun Zhang
- Department of Physiology, Hunan University of Medicine, Huaihua, Hunan, 410208, China
| | - Ping Li
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China
| | - Bruce D Hammcok
- Departments of Entomology and the UC Davis Cancer Center, University of California Davis, Davis, CA, 95616, USA
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China.
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17
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Liu T, Zhou Y, Li P, Duan JX, Liu YP, Sun GY, Wan L, Dong L, Fang X, Jiang JX, Guan CX. Blocking triggering receptor expressed on myeloid cells-1 attenuates lipopolysaccharide-induced acute lung injury via inhibiting NLRP3 inflammasome activation. Sci Rep 2016; 6:39473. [PMID: 28004759 PMCID: PMC5177963 DOI: 10.1038/srep39473] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 11/23/2016] [Indexed: 12/12/2022] Open
Abstract
Acute lung injury (ALI) is associated with high mortality and uncontrolled inflammation plays a critical role in ALI. TREM-1 is an amplifier of inflammatory response, and is involved in the pathogenesis of many infectious diseases. NLRP3 inflammasome is a member of NLRs family that contributes to ALI. However, the effect of TREM-1 on NLRP3 inflammasome and ALI is still unknown. This study aimed to determine the effect of TREM-1 modulation on LPS-induced ALI and activation of the NLRP3 inflammasome. We showed that LR12, a TREM-1 antagonist peptide, significantly improved survival of mice after lethal doses of LPS. LR12 also attenuated inflammation and lung tissue damage by reducing histopathologic changes, infiltration of the macrophage and neutrophil into the lung, and production of the pro-inflammatory cytokine, and oxidative stress. LR12 decreased expression of the NLRP3, pro-caspase-1 and pro-IL-1β, and inhibited priming of the NLRP3 inflammasome by inhibiting NF-κB. LR12 also reduced the expression of NLRP3 and caspase-1 p10 protein, and secretion of the IL-1β, inhibited activation of the NLRP3 inflammasome by decreasing ROS. For the first time, these data show that TREM-1 aggravates inflammation in ALI by activating NLRP3 inflammasome, and blocking TREM-1 may be a potential therapeutic approach for ALI.
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Affiliation(s)
- Tian Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Ping Li
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Jia-Xi Duan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Yong-Ping Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Guo-Ying Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Li Wan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Liang Dong
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China.,Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou 56300, China
| | - Xiang Fang
- Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jian-Xin Jiang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, China
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18
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Silencing Triggering Receptors Expressed on Myeloid Cells-1 Impaired the Inflammatory Response to Oxidized Low-Density Lipoprotein in Macrophages. Inflammation 2016; 39:199-208. [PMID: 26277357 DOI: 10.1007/s10753-015-0239-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Atherosclerosis is a chronic progressive inflammatory disease characterized by the accumulation of lipid contents in arterial walls. Previous studies suggest participation of Toll-like receptors (TLRs) in lipid deposition and inflammatory response in vascular wall. The triggering receptor expressed on myeloid cells 1 (TREM-1) is a cell surface receptor of the immunoglobulin superfamily, which amplifies signal transduction of TLR pathway and enhances immune response to microbial infections. The aim of the present study was to investigate the effect of the oxidized low-density lipoprotein (oxLDL) on the expression of the TREM-1, as well as its engagement in proinflammatory cytokine production and foam cell formation in RAW264.7 mice macrophages. oxLDL enhanced TREM-1 and TLR-4, but not TLR-2 gene expression in macrophages; furthermore, silencing TREM-1 expression by short hairpin interfering RNA inhibited lipid phagocytosis and proinflammatory tumor necrosis factor-α (TNF-α) as well as interleukin-6 (IL-6) production in macrophages; moreover, application of synthetic antagonist, LP-17 polypeptide, reduced IL-6 production upon oxLDL stimulation in vitro and in vivo. In conclusion, in macrophages, oxLDL enhanced expression of TREM-1, which amplifies the innate immune response of TLR pathway; activation of TREM-1 contributes to atherogenesis process by enhancing proinflammatory cytokine production and foam cell formation.
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19
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Chen SS, Wang K, Zhao J, Wu WC, Wu YF, Zhao L. Increased expression of triggering receptor expressed on myeloid cells 1 and 2 in inflamed human gingiva. J Periodontal Res 2016; 52:512-521. [PMID: 27624412 DOI: 10.1111/jre.12417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND OBJECTIVE Periodontitis is an infectious disease in which the host immune and inflammatory responses play essential roles in resistance to bacterial infection, as well as the induction of tissue destruction if the immune response is dysregulated. The triggering receptor expressed on myeloid cells (TREMs) modulates inflammatory and innate immune signaling. TREM-1 is considered as an amplifier of the immune response, while TREM-2 is a negative regulator that has yet to be explored in periodontal disease before. We hypothesized that TREMs participated in the innate immune responses during the pathogenesis of periodontitis. Therefore, the aim of this study was to evaluate TREM-1 and TREM-2 expression in the gingival tissues from patients with chronic periodontitis and healthy subjects as well as their correlation with clinical periodontal parameters. This study is the first to identify TREM-2 in periodontal tissue, as well as the protein expression changes of TREM-1 and TREM-2 in periodontal tissues. MATERIAL AND METHODS Gingival tissue sections were collected from 31 healthy subjects and 53 patients with chronic periodontitis. Immunohistochemistry and quantitative real-time polymerase chain reaction were employed to evaluate the protein and mRNA expression of these receptors in gingival tissues. The recorded clinical parameters were probing depth, clinical attachment loss, plaque index and bleeding on probing. RESULTS In addition to myeloid cells in gingival connective tissues, TREM-1 and TREM-2 were also found expressed in gingival epithelial cells. In particular, TREM-1 was detected in almost all gingival epithelium from both healthy and inflamed biopsies. The expression levels of TREM-1 and TREM-2 were significantly increased in the periodontitis group compared to the healthy group. Increased levels of these receptors are to be positively correlated with site-specific periodontal parameters. CONCLUSION The increased expression of TREM-1 and TREM-2 levels in periodontitis may confer diagnostic and potential therapeutic targets as well as indicating their association with the clinical severity of the disease.
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Affiliation(s)
- S S Chen
- State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Periodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - K Wang
- State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Stomatology, University of Electronic Science and Technology of China Hospital, Chengdu, Sichuan, China
| | - J Zhao
- Department of Epidemiology and Biostatistics, School of Public Health, Curtin University, Perth, WA, Australia
| | - W C Wu
- State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Y F Wu
- Department of Periodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - L Zhao
- Department of Periodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
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20
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Yu CH, Yu WY, Fang J, Zhang HH, Ma Y, Yu B, Wu F, Wu XN. Mosla scabra flavonoids ameliorate the influenza A virus-induced lung injury and water transport abnormality via the inhibition of PRR and AQP signaling pathways in mice. JOURNAL OF ETHNOPHARMACOLOGY 2016; 179:146-155. [PMID: 26719287 DOI: 10.1016/j.jep.2015.12.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 12/17/2015] [Accepted: 12/20/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACROLOGICAL RELEVANCE Mosla scabra (Thunb.) C.Y. Wu and H.W. Li has been used as a traditional medicinal herb for centuries in East Asian countries. It has antibacterial, antiviral, antioxidant, anti-inflammatory and immunomodulatory effects. In folk medicine, it is used as a remedy for the treatment of pulmonary diseases, such as fever, cold, cough, pulmonary edema and emphysema. AIM OF THE STUDY This study was to investigate the protective mechanism of total flavonoids from M. scabra (MF) in influenza A virus (IAV)-infected mice. MATERIALS AND METHODS The mice were infected with IAV and then were treated daily with MF for five days. At the end of the experiment, the levels of inflammatory-related cytokines (IFN-α, IL-6, TNF-α and IL-1β) were determined by ELISA. Pathological changes of lung tissue were examined by H&E staining. The protein expressions of AQP5, p-p38, caspase-3 and NF-κB p65 were detected by western blot analysis while the gene expressions of key effectors in AQP5 and PRRs signaling pathways were detected by real-time Fluorescence Quantitative Polymerase Chain Reaction (RFQ-PCR) analysis. RESULTS The results showed that treatment with MF at doses of 120-360mg/kg for five days to IAV-infected mice significantly attenuated IAV-induced pulmonary injury and decreased the serum levels of IL-6, TNF-α and IL-1β, but increased IFN-α levels. MF treatment could up-regulate the mRNA expressions of TLR-7, RIG-1, TRAF6, Bcl-2, Bax, VIPR1, PKCα and AQP5 and down-regulate caspase-3 and NF-κB p65 protein expression. CONCLUSION Treatment with MF could significantly alleviate IAV-induced pulmonary inflammation, apoptosis and water transport abnormality, which was probably through the regulation of TLR7, RIG-1 and AQP5 signaling pathway.
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Affiliation(s)
- Chen-Huan Yu
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Wen-Ying Yu
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Jie Fang
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Huan-Huan Zhang
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Yue Ma
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Bing Yu
- College of Pharmacy, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Fang Wu
- Key Laboratory of Experimental Animal and Safety Evaluation, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China; College of Pharmacy, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Xiao-Ning Wu
- Pharmaceutical Department, Zhejiang Medical College, Hangzhou 310053, China.
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21
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Peng L, Zhou Y, Dong L, Chen RQ, Sun GY, Liu T, Ran WZ, Fang X, Jiang JX, Guan CX. TGF-β1 Upregulates the Expression of Triggering Receptor Expressed on Myeloid Cells 1 in Murine Lungs. Sci Rep 2016; 6:18946. [PMID: 26738569 PMCID: PMC4704059 DOI: 10.1038/srep18946] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 12/01/2015] [Indexed: 01/05/2023] Open
Abstract
Triggering receptor expressed on myeloid cells 1 (TREM-1) increases the expression of TGF-β family genes, which are known as profibrogenic cytokines in the pathogenesis of pulmonary fibrosis. In this study, we determined whether TGF-β1 regulated the expression of TREM-1 in a mouse model of pulmonary fibrosis. The expression of TGF-β1 and TREM-1 was increased on day 7, 14, and 21 after single intratracheal injection of bleomycin (BLM). And there was positive correlation between the expression of TGF-β1 and TREM-1. TGF-β1 increased expression of TREM-1 mRNA and protein in a time- and dose-dependent manner in mouse macrophages. The expression of the activator protein 1 (AP-1) was increased in lung tissues from mouse after BLM injection and in mouse macrophages after TGF-β1 treatment, respectively. TGF-β1 significantly increased the relative activity of luciferase in the cells transfected with plasmid contenting wild type-promoter of TREM-1. But TGF-β1 had no effect on the activity of luciferase in the cells transfected with a mutant-TREM1 plasmid carrying mutations in the AP-1 promoter binding site. In conclusion, we found the expression of TREM-1 was increased in lung tissues from mice with pulmonary fibrosis. TGF-β1 increased the expression of TREM-1 in mouse macrophages partly via the transcription factor AP-1.
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Affiliation(s)
- Li Peng
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Liang Dong
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Rui-Qi Chen
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Guo-Ying Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Tian Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Wen-Zhuo Ran
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xiang Fang
- Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jian-Xin Jiang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
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22
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Ludewig P, Gallizioli M, Urra X, Behr S, Brait VH, Gelderblom M, Magnus T, Planas AM. Dendritic cells in brain diseases. Biochim Biophys Acta Mol Basis Dis 2015; 1862:352-67. [PMID: 26569432 DOI: 10.1016/j.bbadis.2015.11.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/05/2015] [Accepted: 11/05/2015] [Indexed: 12/25/2022]
Affiliation(s)
- Peter Ludewig
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mattia Gallizioli
- Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - Xabier Urra
- Functional Unit of Cerebrovascular Diseases, Hospital Clínic, Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Sarah Behr
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Vanessa H Brait
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Mathias Gelderblom
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Magnus
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anna M Planas
- Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
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23
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Nguyen AH, Koenck C, Quirk SK, Lim VM, Mitkov MV, Trowbridge RM, Hunter WJ, Agrawal DK. Triggering Receptor Expressed on Myeloid Cells in Cutaneous Melanoma. Clin Transl Sci 2015; 8:441-4. [PMID: 26184544 DOI: 10.1111/cts.12308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The tumor microenvironment plays an important role in the progression of melanoma, the prototypical immunologic cutaneous malignancy. The triggering receptor expressed on myeloid cells (TREM) family of innate immune receptors modulates inflammatory and innate immune signaling. It has been investigated in various neoplastic diseases, but not in melanoma. This study examines the expression of TREM-1 (a proinflammatory amplifier) and TREM-2 (an anti-inflammatory modulator and phagocytic promoter) in human cutaneous melanoma and surrounding tissue. Indirect immunofluorescence staining was performed on skin biopsies from 10 melanoma patients and staining intensity was semiquantitatively scored. Expression of TREM-1 and TREM-2 was higher in keratinocytes than melanoma tissue (TREM-1: p < 0.01; TREM-2: p < 0.01). Whereas TREM-2 was the dominant isoform expressed in normal keratinocytes, TREM-1 expression predominated in melanoma tissue (TREM-1 to TREM-2 ratio: keratinocytes = 0.78; melanoma = 2.08; p < 0.01). The increased TREM ratio in melanoma tissue could give rise to a proinflammatory and protumor state of the microenvironment. This evidence may be suggestive of a TREM-1/TREM-2 paradigm in which relative levels dictate inflammatory and immune states, rather than absolute expression of one or the other. Further investigation regarding this paradigm is warranted and could carry prognostic or therapeutic value in treatment for melanoma.
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Affiliation(s)
- Austin Huy Nguyen
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Carleigh Koenck
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Shannon K Quirk
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Victoria M Lim
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Mario V Mitkov
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Ryan M Trowbridge
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - William J Hunter
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Devendra K Agrawal
- Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
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24
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Ran WZ, Dong L, Tang CY, Zhou Y, Sun GY, Liu T, Liu YP, Guan CX. Vasoactive intestinal peptide suppresses macrophage-mediated inflammation by downregulating interleukin-17A expression via PKA- and PKC-dependent pathways. Int J Exp Pathol 2015; 96:269-75. [PMID: 25944684 DOI: 10.1111/iep.12130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 03/16/2015] [Indexed: 12/13/2022] Open
Abstract
Interleukin (IL)-17A is a pro-inflammatory cytokine that markedly enhances inflammatory responses in the lungs by recruiting neutrophils and interacting with other pro-inflammatory mediators. Reducing the expression of IL-17A could attenuate inflammation in the lungs. However, whether VIP exerts its anti-inflammatory effects by regulating the expression of IL-17A has remained unclear. Here, we show that there is a remarkable increase of IL-17A in bronchoalveolar lavage fluid (BALF) and lung tissue of mice with acute lung injury (ALI). Moreover, lipopolysaccharides (LPS) stimulated elevated expression of IL-17A, which was evident by the enhanced levels of mRNA and protein observed. Furthermore, we also found that VIP inhibited LPS-mediated IL-17A expression in a time- and dose-dependent manner in an in vitro model of ALI and that this process might be mediated via the phosphokinase A (PKA) and phosphokinase C (PKC) pathways. Taken together, our results demonstrated that VIP might be an effective protector during ALI by suppressing IL-17A expression.
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Affiliation(s)
- Wen-Zhuo Ran
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Liang Dong
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China.,Department of Anesthesiology, People's Hospital of Liuzhou City, Liuzhou, China
| | - Chun-Yan Tang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yong Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Guo-Ying Sun
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Tian Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yong-Ping Liu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Cha-Xiang Guan
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, China
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25
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Innate immunity components and cytokines in gastric mucosa in children with Helicobacter pylori infection. Mediators Inflamm 2015; 2015:176726. [PMID: 25948881 PMCID: PMC4407632 DOI: 10.1155/2015/176726] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/18/2014] [Indexed: 12/26/2022] Open
Abstract
PURPOSE. To investigate the expression of innate immunity components and cytokines in the gastric mucosa among H. pylori infected and uninfected children. Materials and Methods. Biopsies of the antral gastric mucosa from children with dyspeptic symptoms were evaluated. Gene expressions of innate immunity receptors and cytokines were measured by quantitative real-time PCR. The protein expression of selected molecules was tested by immunohistochemistry. RESULTS. H. pylori infection did not lead to a significant upregulation of MyD88, TLR2, TLR4, CD14, TREM1, and TREM2 mRNA expression but instead resulted in high mRNA expression of IL-6, IL-10, IFN-γ, TNF-α, and CD163. H. pylori cagA(+) infection was associated with higher IL-6 and IL-10 mRNA expression, as compared to cagA(-) strains. H. pylori infected children showed increased IFN-γ and TNF-α protein levels. IFN-γ mRNA expression correlated with both H. pylori density of colonization and lymphocytic infiltration in the gastric mucosa, whereas TNF-α protein expression correlated with bacterial density. CONCLUSION. H. pylori infection in children was characterized by (a) Th1 expression profile, (b) lack of mRNA overexpression of natural immunity receptors, and (c) strong anti-inflammatory activities in the gastric mucosa, possibly resulting from increased activity of anti-inflammatory M2 macrophages. This may explain the mildly inflammatory gastric inflammation often observed among H. pylori infected children.
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Yaghmoor F, Noorsaeed A, Alsaggaf S, Aljohani W, Scholtzova H, Boutajangout A, Wisniewski T. The Role of TREM2 in Alzheimer's Disease and Other Neurological Disorders. JOURNAL OF ALZHEIMER'S DISEASE & PARKINSONISM 2014; 4:160. [PMID: 25664220 PMCID: PMC4317331 DOI: 10.4172/2161-0460.1000160] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. Late-onset AD (LOAD), is the most common form of Alzheimer's disease, representing about >95% of cases and early-onset AD represents <5% of cases. Several risk factors have been discovered that are associated with AD, with advancing age being the most prominent. Other environmental risk factors include diabetes mellitus, level of physical activity, educational status, hypertension and head injury. The most well known genetic risk factor for LOAD is inheritance of the apolipoprotein (apo) E4 allele. Recently, rare variants of TREM2 have been reported as a significant risk factor for LOAD, comparable to inheritance of apoE4. In this review we will focus on the role(s) of TREM2 in AD as well as in other neurodegenerative disorders.
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Affiliation(s)
- Faris Yaghmoor
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Ahmed Noorsaeed
- Pathology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Samar Alsaggaf
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Waleed Aljohani
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Henrieta Scholtzova
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Allal Boutajangout
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Psychiatry, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Physiology and Neuroscience, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY10016, USA
- King Abdulaziz University, School of Medicine, Jeddah, Saudi Arabia
| | - Thomas Wisniewski
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Pathology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Psychiatry, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
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Sharif O, Gawish R, Warszawska JM, Martins R, Lakovits K, Hladik A, Doninger B, Brunner J, Korosec A, Schwarzenbacher RE, Berg T, Kralovics R, Colinge J, Mesteri I, Gilfillan S, Salmaggi A, Verschoor A, Colonna M, Knapp S. The triggering receptor expressed on myeloid cells 2 inhibits complement component 1q effector mechanisms and exerts detrimental effects during pneumococcal pneumonia. PLoS Pathog 2014; 10:e1004167. [PMID: 24945405 PMCID: PMC4055749 DOI: 10.1371/journal.ppat.1004167] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 04/07/2014] [Indexed: 11/18/2022] Open
Abstract
Phagocytosis and inflammation within the lungs is crucial for host defense during bacterial pneumonia. Triggering receptor expressed on myeloid cells (TREM)-2 was proposed to negatively regulate TLR-mediated responses and enhance phagocytosis by macrophages, but the role of TREM-2 in respiratory tract infections is unknown. Here, we established the presence of TREM-2 on alveolar macrophages (AM) and explored the function of TREM-2 in the innate immune response to pneumococcal infection in vivo. Unexpectedly, we found Trem-2(-/-) AM to display augmented bacterial phagocytosis in vitro and in vivo compared to WT AM. Mechanistically, we detected that in the absence of TREM-2, pulmonary macrophages selectively produced elevated complement component 1q (C1q) levels. We found that these increased C1q levels depended on peroxisome proliferator-activated receptor-δ (PPAR-δ) activity and were responsible for the enhanced phagocytosis of bacteria. Upon infection with S. pneumoniae, Trem-2(-/-) mice exhibited an augmented bacterial clearance from lungs, decreased bacteremia and improved survival compared to their WT counterparts. This work is the first to disclose a role for TREM-2 in clinically relevant respiratory tract infections and demonstrates a previously unknown link between TREM-2 and opsonin production within the lungs.
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MESH Headings
- Animals
- Apoptosis
- Cell Line, Transformed
- Cells, Cultured
- Complement C1q/genetics
- Complement C1q/metabolism
- Cytokines/metabolism
- Disease Models, Animal
- Female
- Lung/cytology
- Lung/immunology
- Lung/metabolism
- Lung/pathology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/pathology
- Male
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Neutrophil Infiltration
- PPAR gamma/metabolism
- Phagocytosis
- Pneumonia, Pneumococcal/immunology
- Pneumonia, Pneumococcal/metabolism
- Pneumonia, Pneumococcal/pathology
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Respiratory Mucosa/cytology
- Respiratory Mucosa/immunology
- Respiratory Mucosa/metabolism
- Respiratory Mucosa/pathology
- Survival Analysis
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Affiliation(s)
- Omar Sharif
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
- * E-mail: (OS); (SK)
| | - Riem Gawish
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Joanna M. Warszawska
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Rui Martins
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Karin Lakovits
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Anastasiya Hladik
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Bianca Doninger
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Julia Brunner
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Ana Korosec
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Roland E. Schwarzenbacher
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Tiina Berg
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Robert Kralovics
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Jacques Colinge
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Ildiko Mesteri
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Susan Gilfillan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Andrea Salmaggi
- Department of Clinical Neurosciences, Istituto Nazionale Neurologico Carlo Besta, Milano, Italy
| | - Admar Verschoor
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University Munich, Munich, Germany
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sylvia Knapp
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
- * E-mail: (OS); (SK)
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Abstract
Recent works have demonstrated a rare functional variant (R47H) in triggering receptor expressed on myeloid cells (TREM) 2 gene, encoding TREM2 protein, increase susceptibility to late-onset Alzheimer's disease (AD), with an odds ratio similar to that of the apolipoprotein E ε4 allele. The reduced function of TREM2 was speculated to be the main cause in the pathogenic effects of this risk variant, and TREM2 is highly expressed in white matter, as well as in the hippocampus and neocortex, which is partly consistent with the pathological features reported in AD brain, indicating the possible involvement of TREM2 in AD pathogenesis. Emerging evidence has demonstrated that TREM2 could suppress inflammatory response by repression of microglia-mediated cytokine production and secretion, which may prevent inflammation-induced bystander damage of neurons. TREM2 also participates in the regulation of phagocytic pathways that are responsible for the removal of neuronal debris. In this article, we review the recent epidemiological findings of TREM2 that related with late-onset AD and speculate the possible roles of TREM2 in progression of this disease. Based on the potential protective actions of TREM2 in AD pathogenesis, targeting TREM2 might provide new opportunities for AD treatment.
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Gao X, Dong Y, Liu Z, Niu B. Silencing of triggering receptor expressed on myeloid cells-2 enhances the inflammatory responses of alveolar macrophages to lipopolysaccharide. Mol Med Rep 2013; 7:921-6. [PMID: 23314916 DOI: 10.3892/mmr.2013.1268] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Accepted: 12/18/2012] [Indexed: 11/06/2022] Open
Abstract
Triggering receptor expressed on myeloid cells-2 (TREM-2) has been shown to attenuate inflammatory responses in various cell lines including bone marrow-derived macrophages, hepatic macrophages, osteoclasts and dendritic cells. However, its effects on alveolar macrophages remain unknown. Lentivirus-mediated RNA interference (RNAi) is a post-transcriptional gene silencing method, which is capable of degrading target genes specifically and efficiently. In this study, we silenced TREM-2 in murine alveolar macrophages by using lentivirus-mediated short hairpin RNA (shRNA) and evaluated the effects of TREM-2 silencing on expression of toll-like receptor-4 (TLR-4), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in response to lipopolysaccharide (LPS). Alveolar macrophages were transfected with shRNA targeting TREM-2 by use of lentivirus vector, non-sense shRNA as a negative control or empty lentivirus vector as a blank control. Silencing of TREM-2 was assessed by real‑time fluorescence quantitative PCR and flow cytometry. Following LPS stimulation, the levels of TLR-4, TNF-α and IL-10 expressed in alveolar macrophages were measured by real-time PCR, flow cytometry or ELISA. TREM-2 expression on alveolar macrophages was downregulated significantly by lentivirus-mediated shRNA treatment at the transcriptional and translational levels. However, alveolar macrophages that received non-sense shRNA or empty lentivirus vectors showed no effects on TREM-2 expression. Silencing of TREM-2 enhanced expression of TLR-4, as well as TNF-α and IL-10, by alveolar macrophages following LPS stimulation. These results indicate a significant effect of TREM-2 on attenuating the LPS-induced inflammatory response of murine alveolar macrophages, which may be dependent on TLR-4.
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Affiliation(s)
- Xiaoling Gao
- Department of Respiratory, The Second Hospital of Shanxi Medical University, Taiyuan 030001, PR China
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Current World Literature. Curr Opin Anaesthesiol 2012; 25:260-9. [DOI: 10.1097/aco.0b013e3283521230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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