1
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Xin Y, Xiong S, Zhou L, Lin X. Activation of leukotriene B 4 receptor 1 is a prerequisite for complement receptor 3-mediated antifungal responses of neutrophils. Cell Mol Immunol 2024; 21:245-259. [PMID: 38297112 PMCID: PMC10901876 DOI: 10.1038/s41423-024-01130-4] [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: 06/08/2023] [Accepted: 12/31/2023] [Indexed: 02/02/2024] Open
Abstract
Invasive fungal infections are life-threatening, and neutrophils are vital cells of the innate immune system that defend against them. The role of LTA4H-LTB4-BLT1 axis in regulation of neutrophil responses to fungal infection remains poorly understood. Here, we demonstrated that the LTA4H-LTB4-BLT1 axis protects the host against Candida albicans and Aspergillus fumigatus, but not Cryptococcus neoformans infection, by regulating the antifungal activity of neutrophils. Our results show that deleting Lta4h or Blt1 substantially impairs the fungal-specific phagocytic capacity of neutrophils. Moreover, defective activation of the spleen tyrosine kinase (Syk) and extracellular signal-related kinase (ERK1/2) pathways in neutrophils accompanies this impairment. Mechanistically, BLT1 regulates CR3-mediated, β-1,3-glucan-induced neutrophil phagocytosis, while a physical interaction with CR3 with slight influence on its dynamics is observed. Our findings thus demonstrate that the LTA4H-LTB4-BLT1 axis is essential for the phagocytic function of neutrophils in host antifungal immune response against Candida albicans and Aspergillus fumigatus.
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Affiliation(s)
- Yan Xin
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China
- Tsinghua University-Peking University Center for Life Sciences, 100084, Beijing, China
| | - Sihan Xiong
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China
| | - Linghong Zhou
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Xin Lin
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China.
- Tsinghua University-Peking University Center for Life Sciences, 100084, Beijing, China.
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2
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Nakamura M, Shimizu T. Therapeutic target of leukotriene B 4 receptors, BLT1 and BLT2: Insights from basic research. Biochimie 2023; 215:60-68. [PMID: 37423557 DOI: 10.1016/j.biochi.2023.06.014] [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: 04/04/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/11/2023]
Abstract
Leukotriene B4 (LTB4) is a lipid mediator rapidly generated from arachidonic acid in response to various stimuli. This lipid mediator exerts its biological activities by binding to cognate receptors. Two LTB4 receptors have been cloned; BLT1 and BLT2 as a high- and a low-affinity receptors, respectively. In numerous analyses, physiological and pathophysiological importance of LTB4 and cognate receptors in various diseases has been clarified. For example, disruption of the BLT1 gene or treatment with blockers for this receptor reduced various diseases such as rheumatoid arthritis and bronchial asthma in mice, in contrast BLT2 deficiency facilitated several diseases in the small intestine and the skin. These data support the idea that BLT1 blockers and BLT2 agonists could be useful for the cure of these diseases. Thus, various drugs targeting each receptor are being developed by many pharmaceutical companies. In this review, we focus on our current knowledge of the biosynthesis and physiological roles of LTB4 through cognate receptors. We further describe the effects of these receptor deficiencies on several pathophysiological conditions, including the potential of LTB4 receptors as therapeutic targets for the cure of the diseases. Moreover, current information on the structure and post-translational modification of BLT1 and BLT2 is discussed.
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Affiliation(s)
- Motonao Nakamura
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama, 700-0005, Japan.
| | - Takao Shimizu
- Lipid Signaling, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan; Institute of Microbial Chemistry, Tokyo, 141-0021, Japan
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3
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Coyne ES, Nie Y, Abdurrachim D, Ong CZL, Zhou Y, Ali AAB, Meyers S, Grein J, Blumenschein W, Gongol B, Liu Y, Hugelshofer C, Carballo-Jane E, Talukdar S. Leukotriene B4 receptor 1 ( BLT1) does not mediate disease progression in a mouse model of liver fibrosis. Biochem J 2023; 481:BCJ20230422. [PMID: 38014500 PMCID: PMC10903445 DOI: 10.1042/bcj20230422] [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: 10/03/2023] [Revised: 11/21/2023] [Accepted: 11/27/2023] [Indexed: 11/29/2023]
Abstract
MASH is a prevalent liver disease that can progress to fibrosis, cirrhosis, hepatocellular carcinoma (HCC), and ultimately death, but there are no approved therapies. Leukotriene B4 (LTB4) is a potent pro-inflammatory chemoattractant that drives macrophage and neutrophil chemotaxis, and genetic loss or inhibition of its high affinity receptor, leukotriene B4 receptor 1 (BLT1), results in improved insulin sensitivity and decreased hepatic steatosis. To validate the therapeutic efficacy of BLT1 inhibition in an inflammatory and pro-fibrotic mouse model of MASH and fibrosis, mice were challenged with a choline-deficient, L-amino acid defined high fat diet and treated with a BLT1 antagonist at 30 or 90 mg/kg for 8 weeks. Liver function, histology, and gene expression were evaluated at the end of the study. Treatment with the BLT1 antagonist significantly reduced plasma lipids and liver steatosis but had no impact on liver injury biomarkers or histological endpoints such as inflammation, ballooning, or fibrosis compared to control. Artificial intelligence-powered digital pathology analysis revealed a significant reduction in steatosis co-localized fibrosis in livers treated with the BLT1 antagonist. Liver RNA-seq and pathway analyses revealed significant changes in fatty acid, arachidonic acid, and eicosanoid metabolic pathways with BLT1 antagonist treatment, however, these changes were not sufficient to impact inflammation and fibrosis endpoints. Targeting this LTB4-BLT1 axis with a small molecule inhibitor in animal models of chronic liver disease should be considered with caution, and additional studies are warranted to understand the mechanistic nuances of BLT1 inhibition in the context of MASH and liver fibrosis.
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Affiliation(s)
| | - Yilin Nie
- Merck & Co., Inc., South San Francisco, CA, U.S.A
| | | | | | | | | | | | - Jeff Grein
- Merck & Co., Inc., South San Francisco, CA, U.S.A
| | | | | | - Yang Liu
- Merck & Co., Inc., South San Francisco, CA, U.S.A
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4
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Tatsumi R, Aihara S, Matsune S, Aoki J, Inoue A, Shimizu T, Nakamura M. Stepwise phosphorylation of BLT1 defines complex assemblies with β-arrestin serving distinct functions. FASEB J 2023; 37:e23213. [PMID: 37795742 DOI: 10.1096/fj.202301440r] [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: 07/15/2023] [Revised: 09/06/2023] [Accepted: 09/08/2023] [Indexed: 10/06/2023]
Abstract
G protein-coupled receptors (GPCRs) utilize complex cellular systems to respond to diverse ligand concentrations. By taking BLT1, a GPCR for leukotriene B4 (LTB4 ), as a model, our previous work elucidated that this system functions through the modulation of phosphorylation status on two specific residues: Thr308 and Ser310 . Ser310 phosphorylation occurs at a lower LTB4 concentration than Thr308 , leading to a shift in ligand affinity from a high-to-low state. However, the implications of BLT1 phosphorylation in signal transduction processes or the underlying mechanisms have remained unclear. Here, we identify the sequential BLT1-engaged conformations of β-arrestin and subsequent alterations in signal transduction. Stimulation of the high-affinity BLT1 with LTB4 induces phosphorylation at Ser310 via the ERK1/2-GRK pathway, resulting in a β-arrestin-bound low-affinity state. This configuration, referred to as the "low-LTB4 -induced complex," necessitates the finger loop region and the phosphoinositide-binding motif of β-arrestins to interact with BLT1 and deactivates the ERK1/2 signaling. Under high LTB4 concentrations, the low-affinity BLT1 again binds to the ligand and triggers the generation of the low-LTB4 -induced complex into a different form termed "high-LTB4 -induced complex." This change is propelled by The308 -phosphorylation-dependent basal phosphorylation by PKCs. Within the high-LTB4 -induced complex, β-arrestin adapts a unique configuration that involves additional N domain interaction to the low-affinity BLT1 and stimulates the PI3K/AKT pathway. We propose that the stepwise phosphorylation of BLT1 defines the formation of complex assemblies, wherein β-arrestins perform distinct functions.
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Affiliation(s)
- Riko Tatsumi
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
| | - Saki Aihara
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
| | - Seiya Matsune
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
| | - Junken Aoki
- Department of Health Chemistry, Graduate School of Pharmaceutical Science, The University of Tokyo, Tokyo, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (AMED-CREST), Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo, Japan
| | - Asuka Inoue
- Department of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Takao Shimizu
- Department of Lipid Signaling, National Center for Global Health and Medicine, National Center for Global Health and Medicine, Tokyo, Japan
- Institute of Microbial Chemistry, Tokyo, Japan
| | - Motonao Nakamura
- Department of Bioscience, Graduate School of Life Science, Okayama University of Science, Okayama, Japan
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5
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Kato S, Onishi S, Sasai M, Yasuda H, Saeki K, Matsumoto K, Yokomizo T. Deficiency of leukotriene B4 receptor type 1 ameliorates ovalbumin-induced allergic enteritis in mice. Clin Exp Pharmacol Physiol 2023. [PMID: 37406678 DOI: 10.1111/1440-1681.13808] [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: 02/21/2023] [Revised: 05/30/2023] [Accepted: 06/24/2023] [Indexed: 07/07/2023]
Abstract
Leukotriene B4 receptor type 1 (BLT1), a high-affinity receptor for leukotriene B4 (LTB4), plays an important role in inflammatory responses, including allergic airway inflammation. In this study, we examined the effect of genetic BLT1 deletion (BLT1KO) on ovalbumin (OVA)-induced allergic enteritis in mice to determine the pathogenic role of LTB4/BLT1 in allergic enteritis, a gastrointestinal form of food allergy. Repeated oral OVA challenges after sensitization with OVA and aluminium potassium sulphate induced allergic enteritis, characterized by systemic allergic symptoms (scratching, immobility and swelling), diarrhoea, colonic oedema and colonic goblet cell hyperplasia, accompanied by increased colonic peroxidase activity, colonic inflammatory cytokine expression and increased serum OVA-specific IgE levels. The severity of enteritis was significantly attenuated in BLT1KO mice compared with wild-type (WT) mice, without an increase in serum OVA-specific IgE levels. The accumulation of neutrophils, eosinophils, M2-macrophages, dendritic cells, CD4+ T cells and mast cells was observed in the colonic mucosa of allergic enteritis, and such accumulation was significantly lower in BLT1KO mice than in WT mice. BLT1 expression was upregulated and colocalized mostly in neutrophils and partly in eosinophils and dendritic cells in the colonic mucosa of allergic enteritis. These findings indicate that BLT1 deficiency ameliorates OVA-induced allergic enteritis in mice and that LTB4/BLT1 contributes to neutrophil and eosinophil accumulation in the allergic colonic mucosa. Therefore, BLT1 is a promising drug target for treating food allergies.
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Affiliation(s)
- Shinichi Kato
- Division of Pathological Sciences, Laboratory of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Suzuka Onishi
- Division of Pathological Sciences, Laboratory of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Misaki Sasai
- Division of Pathological Sciences, Laboratory of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Hiroyuki Yasuda
- Division of Pathological Sciences, Laboratory of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kazuko Saeki
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Bunkyo, Japan
| | - Kenjiro Matsumoto
- Division of Pathological Sciences, Laboratory of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Bunkyo, Japan
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6
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Shioda R, Jo-Watanabe A, Okuno T, Saeki K, Nakayama M, Suzuki Y, Yokomizo T. The leukotriene B 4 / BLT1-dependent neutrophil accumulation exacerbates immune complex-mediated glomerulonephritis. FASEB J 2023; 37:e22789. [PMID: 36692419 DOI: 10.1096/fj.202201936r] [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: 11/20/2022] [Revised: 12/25/2022] [Accepted: 01/11/2023] [Indexed: 01/25/2023]
Abstract
Crescent formation is the most important pathological finding that defines the prognosis of nephritis. Although neutrophils are known to play an important role in the progression of crescentic glomerulonephritis, such as anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis, the key chemoattractant for neutrophils in ANCA-associated glomerulonephritis has not been identified. Here, we demonstrate that a lipid chemoattractant, leukotriene B4 (LTB4 ), and its receptor BLT1 are primarily involved in disease pathogenesis in a mouse model of immune complex-mediated crescentic glomerulonephritis. Circulating neutrophils accumulated into glomeruli within 1 h after disease onset, which was accompanied by LTB4 accumulation in the kidney cortex, leading to kidney injury. LTB4 was produced by cross-linking of Fc gamma receptors on neutrophils. Mice deficient in BLT1 or LTB4 biosynthesis exhibited suppressed initial neutrophil infiltration and subsequent thrombotic glomerulonephritis and renal fibrosis. Depletion of neutrophils before, but not after, disease onset prevented proteinuria and kidney injury, indicating the essential role of neutrophils in the early phase of glomerulonephritis. Administration of a BLT1 antagonist before and after disease onset almost completely suppressed induction of glomerulonephritis. Finally, we found that the glomeruli from patients with ANCA-associated glomerulonephritis contained more BLT1-positive cells than glomeruli from patients with other etiologies. Taken together, the LTB4 -BLT1 axis is the key driver of neutrophilic glomerular inflammation, and will be a novel therapeutic target for the crescentic glomerulonephritis.
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Affiliation(s)
- Ryotaro Shioda
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Airi Jo-Watanabe
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan.,AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Toshiaki Okuno
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kazuko Saeki
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Maiko Nakayama
- Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yusuke Suzuki
- Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, Japan
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7
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Nakamura M, Shimizu T. Recent advances in function and structure of two leukotriene B 4 receptors: BLT1 and BLT2. Biochem Pharmacol 2022; 203:115178. [PMID: 35850310 DOI: 10.1016/j.bcp.2022.115178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 11/21/2022]
Abstract
Leukotriene B4 (LTB4) is generated by the enzymatic oxidation of arachidonic acid, which is then released from the cell membrane and acts as a potent activator of leukocytes and other inflammatory cells. Numerous studies have demonstrated the physiological and pathophysiological significance of this lipid in various diseases. LTB4 exerts its activities by binding to its specific G protein-coupled receptors (GPCRs): BLT1 and BLT2. In mouse disease models, treatment with BLT1 antagonists or BLT1 gene ablation attenuated various diseases, including bronchial asthma, arthritis, and psoriasis, whereas BLT2 deficiency exacerbated several diseases in the skin, cornea, and small intestine. Therefore, BLT1 inhibitors and BLT2 activators could be beneficial for the treatment of several inflammatory and immune disorders. As a result, attractive compounds targeting LTB4 receptors have been developed by several pharmaceutical companies. This review aims to understand the potential of BLT1 and BLT2 as therapeutic targets for the treatment of various inflammatory diseases. In addition, recent topics are discussed with major focuses on the structure and post-translational modifications of BLT1 and BLT2. Collectively, current evidence on modulating LTB4 receptor functions provides new strategies for the treatment of various diseases.
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8
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Koutsogiannaki S, Okuno T, Kobayashi Y, Ogawa N, Yuki K. Isoflurane attenuates sepsis-associated lung injury. Biochem Biophys Res Commun 2022; 599:127-133. [PMID: 35180472 PMCID: PMC8892593 DOI: 10.1016/j.bbrc.2022.02.028] [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: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 11/30/2022]
Abstract
Acute lung injury is one of major complications associated with sepsis, responsible for morbidity and mortality. Patients who suffer from acute lung injury often require respiratory support under sedations, and it would be important to know the role of sedatives in lung injury. We examined volatile anesthetic isoflurane, which is commonly used in surgical setting, but also used as an alternative sedative in intensive care settings in European countries and Canada. We found that isoflurane exposure attenuated neutrophil recruitment to the lungs in mice suffering from experimental polymicrobial abdominal sepsis. We found that isoflurane attenuated one of major neutrophil chemoattractants LTB4 mediated response via its receptor BLT1 in neutrophils. Furthermore, we have shown that isoflurane directly bound to BLT1 by a competition assay using newly developed labeled BLT1 antagonist, suggesting that isoflurane would be a BLT1 antagonist.
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Affiliation(s)
- Sophia Koutsogiannaki
- Department of Anaesthesia and Immunology, Harvard Medical School, USA; Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children's Hospital, USA
| | - Toshiaki Okuno
- Department of Biochemistry, Juntendo University Faculty of Medicine, Japan
| | - Yuichi Kobayashi
- Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, Japan
| | - Narihito Ogawa
- Department of Applied Chemistry, Meiji University, Japan
| | - Koichi Yuki
- Department of Anaesthesia and Immunology, Harvard Medical School, USA; Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children's Hospital, USA.
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9
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Koga T, Sasaki F, Saeki K, Tsuchiya S, Okuno T, Ohba M, Ichiki T, Iwamoto S, Uzawa H, Kitajima K, Meno C, Nakamura E, Tada N, Fukui Y, Kikuta J, Ishii M, Sugimoto Y, Nakao M, Yokomizo T. Expression of leukotriene B 4 receptor 1 defines functionally distinct DCs that control allergic skin inflammation. Cell Mol Immunol 2021; 18:1437-1449. [PMID: 33037399 PMCID: PMC8167169 DOI: 10.1038/s41423-020-00559-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 11/25/2022] Open
Abstract
Leukotriene B4 (LTB4) receptor 1 (BLT1) is a chemotactic G protein-coupled receptor expressed by leukocytes, such as granulocytes, macrophages, and activated T cells. Although there is growing evidence that BLT1 plays crucial roles in immune responses, its role in dendritic cells remains largely unknown. Here, we identified novel DC subsets defined by the expression of BLT1, namely, BLT1hi and BLT1lo DCs. We also found that BLT1hi and BLT1lo DCs differentially migrated toward LTB4 and CCL21, a lymph node-homing chemoattractant, respectively. By generating LTB4-producing enzyme LTA4H knockout mice and CD11c promoter-driven Cre recombinase-expressing BLT1 conditional knockout (BLT1 cKO) mice, we showed that the migration of BLT1hi DCs exacerbated allergic contact dermatitis. Comprehensive transcriptome analysis revealed that BLT1hi DCs preferentially induced Th1 differentiation by upregulating IL-12p35 expression, whereas BLT1lo DCs accelerated T cell proliferation by producing IL-2. Collectively, the data reveal an unexpected role for BLT1 as a novel DC subset marker and provide novel insights into the role of the LTB4-BLT1 axis in the spatiotemporal regulation of distinct DC subsets.
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Affiliation(s)
- Tomoaki Koga
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Fumiyuki Sasaki
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
- Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| | - Kazuko Saeki
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Soken Tsuchiya
- Department of Pharmaceutical Biochemistry, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 862-0973, Japan
| | - Toshiaki Okuno
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Mai Ohba
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Takako Ichiki
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Satoshi Iwamoto
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Hirotsugu Uzawa
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Keiko Kitajima
- Department of Developmental Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Chikara Meno
- Department of Developmental Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Eri Nakamura
- Laboratory of Genome Research, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Norihiro Tada
- Laboratory of Genome Research, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Yoshinori Fukui
- Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, 812-8582, Japan
| | - Junichi Kikuta
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Osaka, 565-0871, Japan
| | - Masaru Ishii
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Osaka, 565-0871, Japan
| | - Yukihiko Sugimoto
- Department of Pharmaceutical Biochemistry, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 862-0973, Japan
| | - Mitsuyoshi Nakao
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan.
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10
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Xie S, Qi X, Wu Q, Wei L, Zhang M, Xing Y, Shi W, Chen S, Zeng X, Wang S, Guo H, Deng W. Inhibition of 5-lipoxygenase is associated with downregulation of the leukotriene B4 receptor 1/ Interleukin-12p35 pathway and ameliorates sepsis-induced myocardial injury. Free Radic Biol Med 2021; 166:348-357. [PMID: 33705958 DOI: 10.1016/j.freeradbiomed.2021.02.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 11/21/2022]
Abstract
Sepsis rapidly contributed to multiorgan failure affecting most commonly of the cardiovascular and respiratory systems and yet there were no effective therapies. The current study aimed at providing evidence on the cardioprotection of suppression of 5-Lipoxygenase (5-Lox) and identifying the possible mechanism in the mouse model of sepsis. The cecal ligation-perforation (CLP) model was applied to C57BL/6 wild-type (WT) and 5-Lox deficient (5-Lox-/-) mice to induce sepsis. 5-Lox expression was up-regulated in mouse myocardium and leukotriene B4 (LTB4) level was increased in serum after sepsis. Subsequently, we utilized a recombinant adenoviral expression vector (rAAV9) to overexpress Alox5 gene in adult mice. Compared to WT mice, 5-Lox overexpression accelerated CLP-induced myocardial injury and cardiac dysfunction. Oppositely, 5-Lox deficiency offered protection against myocardial injury in a mouse model of sepsis and attenuated sepsis-mediated inflammation, oxidative stress and apoptosis in the mouse heart. Mechanically, 5-Lox promoted LTB4 production, which in turn contributed to the activation of leukotriene B4 receptor 1 (BLT1)/interleukin-12p35 (IL-12p35) pathway and enhanced M1 macrophage polarization. However, the suppression of BLT1 by either gene mutation or antagonist U75302 significantly inhibited the adverse effect of 5-Lox in sepsis. Further study demonstrated that pharmacological inhibition of 5-Lox prevented CLP-induced septic cardiomyopathy (SCM). Our study identified 5-Lox exacerbated sepsis-associated myocardial injury through activation of LTB4 production and promoting BLT1/IL-12p35 pathway. Hence, inhibition of 5-Lox may be a potential candidate strategy for septic cardiac dysfunction treatment.
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Affiliation(s)
- Saiyang Xie
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Xiping Qi
- Department of Transfusion, Wuhan Hospital of Traditional Chinese and Western Medicine (Wuhan No.1 Hospital), Wuhan, 430060, China
| | - Qingqing Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Li Wei
- Department of Pediatrics, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Min Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Yun Xing
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Wenke Shi
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Si Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Xiaofeng Zeng
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Shasha Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China
| | - Haipeng Guo
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan, 250012, China; Department of Critical Care Medicine, Qilu Hospital of Shandong University, 107 Wenhuaxi Road, Jinan, 250012, China
| | - Wei Deng
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, 430060, China.
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11
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Eskandarpour M, Nunn MA, Weston-Davies W, Calder VL. Immune-Mediated Retinal Vasculitis in Posterior Uveitis and Experimental Models: The Leukotriene (LT)B4-VEGF Axis. Cells 2021; 10:cells10020396. [PMID: 33671954 PMCID: PMC7919050 DOI: 10.3390/cells10020396] [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] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 02/07/2023] Open
Abstract
Retinal vascular diseases have distinct, complex and multifactorial pathogeneses yet share several key pathophysiological aspects including inflammation, vascular permeability and neovascularisation. In non-infectious posterior uveitis (NIU), retinal vasculitis involves vessel leakage leading to retinal enlargement, exudation, and macular oedema. Neovascularisation is not a common feature in NIU, however, detection of the major angiogenic factor—vascular endothelial growth factor A (VEGF-A)—in intraocular fluids in animal models of uveitis may be an indication for a role for this cytokine in a highly inflammatory condition. Suppression of VEGF-A by directly targeting the leukotriene B4 (LTB4) receptor (BLT1) pathway indicates a connection between leukotrienes (LTs), which have prominent roles in initiating and propagating inflammatory responses, and VEGF-A in retinal inflammatory diseases. Further research is needed to understand how LTs interact with intraocular cytokines in retinal inflammatory diseases to guide the development of novel therapeutic approaches targeting both inflammatory mediator pathways.
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Affiliation(s)
- Malihe Eskandarpour
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK;
- Correspondence:
| | - Miles A. Nunn
- Akari Therapeutics Plc, London EC1V 9EL, UK; (M.A.N.); (W.W.-D.)
| | | | - Virginia L. Calder
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK;
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12
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Hirakata T, Matsuda A, Yokomizo T. Leukotriene B 4 receptors as therapeutic targets for ophthalmic diseases. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158756. [PMID: 32535236 DOI: 10.1016/j.bbalip.2020.158756] [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: 02/25/2020] [Revised: 06/01/2020] [Accepted: 06/04/2020] [Indexed: 11/26/2022]
Abstract
Leukotriene B4 (LTB4) is an inflammatory lipid mediator produced from arachidonic acid by multiple reactions catalyzed by two enzymes 5-lipoxygenase (5-LOX) and LTA4 hydrolase (LTA4H). The two receptors for LTB4 have been identified: a high-affinity receptor, BLT1, and a low-affinity receptor, BLT2. Our group identified 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (12-HHT) as a high-affinity BLT2 ligand. Numerous studies have revealed critical roles for LTB4 and its receptors in various systemic diseases. Recently, we also reported the roles of LTB4, BLT1 and BLT2 in the murine ophthalmic disease models of mice including cornea wound, allergic conjunctivitis, and age-related macular degeneration. Moreover, other groups revealed the evidence of the ocular function of LTB4. In the present review, we introduce the roles of LTB4 and its receptors both in ophthalmic diseases and systemic inflammatory diseases. LTB4 and its receptors are putative novel therapeutic targets for systemic and ophthalmic diseases.
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Affiliation(s)
- Toshiaki Hirakata
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, Japan; Department of Biochemistry, Juntendo University Graduate School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, Japan
| | - Akira Matsuda
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, Japan.
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13
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Abstract
Leukotriene B4 (LTB4) is a major type of lipid mediator that is rapidly generated from arachidonic acid through sequential action of 5-lipoxygenase (5-LO), 5-lipoxygenase-activating protein (FLAP) and LTA4 hydrolase (LTA4H) in response to various stimuli. LTB4 is well known to be a chemoattractant for leukocytes, particularly neutrophils, via interaction with its high-affinity receptor BLT1. Extensive attention has been paid to the role of the LTB4-BLT1 axis in acute and chronic inflammatory diseases, such as infectious diseases, allergy, autoimmune diseases, and metabolic disease via mediating recruitment and/or activation of different types of inflammatory cells depending on different stages or the nature of inflammatory response. Recent studies also demonstrated that LTB4 acts on non-immune cells via BLT1 to initiate and/or amplify pathological inflammation in various tissues. In addition, emerging evidence reveals a complex role of the LTB4-BLT1 axis in cancer, either tumor-inhibitory or tumor-promoting, depending on the different target cells. In this review, we summarize both established understanding and the most recent progress in our knowledge about the LTB4-BLT1 axis in host defense, inflammatory diseases and cancer.
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Affiliation(s)
- Rui He
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, People's Republic of China.
| | - Yu Chen
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Qian Cai
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, People's Republic of China
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14
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Sasaki F, Yokomizo T. The leukotriene receptors as therapeutic targets of inflammatory diseases. Int Immunol 2020; 31:607-615. [PMID: 31135881 DOI: 10.1093/intimm/dxz044] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 05/27/2019] [Indexed: 12/11/2022] Open
Abstract
Leukotrienes (LTs) are inflammatory mediators derived from arachidonic acid. LTs include the di-hydroxy acid LT (LTB4) and the cysteinyl LTs (CysLTs; LTC4, LTD4 and LTE4), all of which are involved in both acute and chronic inflammation. We and other groups identified a high-affinity LTB4 receptor, BLT1; the LTC4 and LTD4 receptors, CysLT1 and CysLT2; and the LTE4 receptor, GPR99. Pharmacological studies have shown that BLT1 signaling stimulates degranulation, chemotaxis and phagocytosis of neutrophils, whereas CysLT1 and CysLT2 signaling induces airway inflammation by increasing vascular permeability and the contraction of bronchial smooth muscle. Recently, we and other groups suggested that the LTB4-BLT1 axis and the cysteinyl LTs-CysLT1/2 axis are involved in chronic inflammatory diseases including asthma, atopic dermatitis, psoriasis, atherosclerosis, arthritis, obesity, cancer and age-related macular degeneration using animal models for disease and gene knockout mice. This review describes the classical and novel functions of LTs and their receptors in several inflammatory diseases and discusses the potential clinical applications of antagonists for LT receptors and inhibitors of LT biosynthesis.
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Affiliation(s)
- Fumiyuki Sasaki
- Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan
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15
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Kurakin GF, Lopina NP, Bordina GE. [Comparative Computational Modeling of Agonist Binding to the Leukotriene Receptors BLT1 and BLT2]. Mol Biol (Mosk) 2020; 54:341-352. [PMID: 32392205 DOI: 10.31857/s002689842002010x] [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: 02/25/2019] [Accepted: 09/17/2019] [Indexed: 11/24/2022]
Abstract
The leukotriene B4 receptors BLT1 and BLT2 are promising targets for the treatment of allergic and inflammatory diseases. However, no working model of ligand binding to either of these receptors has been developed so far. Under the assumption that homologous receptors bind their ligands in a similar way, computational modeling of agonist binding to BLT1 and BLT2 was performed using fully flexible docking in Galaxy 7TM. For both receptors, the carboxyl group of the ligand forms a salt bridge with an arginine residue, while the tail hydroxyl groups form hydrogen bonds with three amino acid residues. The differential specificity of ligands to BLT1 and BLT2 is explained by the replacement of histidine with tyrosine. In BLT1, the histidine residue binds the 5-OH group of the ligand, while the tyrosine residue in BLT2 repels it. The presented models are in agreement with experimental data and may be useful for developing new BLT1- and BLT2-targeted drugs.
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Affiliation(s)
- G F Kurakin
- Tver State Medical University, Ministry of Health of the Russian Federation, Tver, 170000 Russia.,
| | - N P Lopina
- Tver State Medical University, Ministry of Health of the Russian Federation, Tver, 170000 Russia
| | - G E Bordina
- Tver State Medical University, Ministry of Health of the Russian Federation, Tver, 170000 Russia
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16
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Hilliard KA, Blaho VA, Jackson CD, Brown CR. Leukotriene B4 receptor BLT1 signaling is critical for neutrophil apoptosis and resolution of experimental Lyme arthritis. FASEB J 2019; 34:2840-2852. [PMID: 31908031 DOI: 10.1096/fj.201902014r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 08/07/2019] [Revised: 12/04/2019] [Accepted: 12/10/2019] [Indexed: 11/11/2022]
Abstract
Eicosanoids are powerful mediators of inflammation and are known to drive both the progression and regression of arthritis. We previously reported the infection of C3H 5-lipoxygenase (LO)-deficient mice with Borrelia burgdorferi results in prolonged nonresolving Lyme arthritis. Here we define the role of the 5-LO metabolite leukotriene (LT)B4 and its high-affinity receptor, BLT1, in this response. C3H and C3H BLT1-/- mice were infected with B. burgdorferi and arthritis progression was monitored by ankle swelling over time. Similar to 5-LO-/- mice, BLT1-/- mice developed nonresolving Lyme arthritis characterized by increased neutrophils in the joint at later time points than WT mice, but with fewer apoptotic (caspase-3+ ) neutrophils. In vitro, BLT1-/- neutrophils were defective in their ability to undergo apoptosis due to the lack of LTB4 -mediated down-regulation of cAMP, subsequent failure to induce Death-Inducing Signaling Complex (DISC) components, and decreased FasL and CD36 expression. Inhibition of adenylyl cyclase with SQ 22,536 restored BLT1-/- BMN apoptosis, FasL and CD36 expression, and clearance by macrophages. We conclude that LTB4/BLT1 signaling has an unexpected critical role in mediating neutrophil apoptosis via the down-regulation of cAMP. Loss of BLT1 signaling led to defective clearance of neutrophils from the inflamed joint and failed arthritis resolution.
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Affiliation(s)
- Kinsey A Hilliard
- Department of Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Victoria A Blaho
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, USA
| | - Christa D Jackson
- Department of Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Charles R Brown
- Department of Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
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17
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Jo-Watanabe A, Okuno T, Yokomizo T. The Role of Leukotrienes as Potential Therapeutic Targets in Allergic Disorders. Int J Mol Sci 2019; 20:ijms20143580. [PMID: 31336653 PMCID: PMC6679143 DOI: 10.3390/ijms20143580] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/17/2019] [Accepted: 07/19/2019] [Indexed: 12/13/2022] Open
Abstract
Leukotrienes (LTs) are lipid mediators that play pivotal roles in acute and chronic inflammation and allergic diseases. They exert their biological effects by binding to specific G-protein-coupled receptors. Each LT receptor subtype exhibits unique functions and expression patterns. LTs play roles in various allergic diseases, including asthma (neutrophilic asthma and aspirin-sensitive asthma), allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and anaphylaxis. This review summarizes the biology of LTs and their receptors, recent developments in the area of anti-LT strategies (in settings such as ongoing clinical studies), and prospects for future therapeutic applications.
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Affiliation(s)
- Airi Jo-Watanabe
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Toshiaki Okuno
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
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18
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Zhao S, Yao K, Li D, Liu K, Jin G, Yan M, Wu Q, Chen H, Shin SH, Bai R, Wang G, Bode AM, Dong Z, Guo Z, Dong Z. Inhibition of LTA4H by bestatin in human and mouse colorectal cancer. EBioMedicine 2019; 44:361-74. [PMID: 31085102 DOI: 10.1016/j.ebiom.2019.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/19/2019] [Accepted: 05/03/2019] [Indexed: 02/06/2023] Open
Abstract
Background Our preclinical data showed that the leukotriene A4 hydrolase (LTA4H) pathway plays a role in colorectal cancer (CRC). High expression of LTA4H and leukotriene B4 receptor type 1 (BLT1) were also associated with CRC survival probability. Clinical samples were evaluated to determine whether LTA4H could serve as a therapeutic target and whether leukotriene B4 (LTB4) could be used as a biomarker for evaluating the efficacy of bestatin in CRC. Methods Patients with Stage I-III CRC did or did not receive bestatin prior to surgery. Evaluable pairwise CRC patient blood samples were collected to evaluate LTB4 concentration. Tissues were processed by immunohistochemistry to detect the LTA4H pathway and Ki-67 expression. We also determined whether LTA4H or BLT1 was associated with CRC survival probability and explored the mechanism of bestatin action in CRC. Findings Samples from 13 CRC patients showed a significant decrease in LTB4, the LTA4H signaling pathway, and Ki-67 in the bestatin-treated group compared with the untreated group. LTA4H and BLT1 are overexpressed in CRC and associated with CRC survival probability. Bestatin effectively inhibited LTB4 and tumorigenesis in the ApcMin/+ and CRC patient-derived xenograft mouse model. Interpretation These results demonstrate that LTB4 could serve as a biomarker for evaluating bestatin efficacy in CRC and the antitumor effects of bestatin through its targeting of LTA4H and support further studies focusing on LTA4H inhibition in CRC.
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19
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Sanden M, Botha J, Nielsen MRS, Nielsen MH, Schmidt EB, Handberg A. BLTR1 and CD36 Expressing Microvesicles in Atherosclerotic Patients and Healthy Individuals. Front Cardiovasc Med 2018; 5:156. [PMID: 30425991 PMCID: PMC6218418 DOI: 10.3389/fcvm.2018.00156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 05/18/2018] [Accepted: 10/12/2018] [Indexed: 12/25/2022] Open
Abstract
Aims: Monocytes/macrophages play a crucial role in the development, progression, and complication of atherosclerosis. In particular, foam cell formation driven by CD36 mediated internalization of oxLDL leads to activation of monocytes and subsequent release of microvesicles (MVs) derived from monocytes (MMVs). Further, pro-inflammatory leukotriene B4 (LTB4) derived from arachidonic acid promotes atherosclerosis through the high-affinity receptor BLTR1. Thus, we aimed to investigate the correlation between different MMV phenotypes (CD14+ MVs) on the one hand, and arachidonic acid and eicosapentaenoic acid contents in different compartments including atherosclerotic plaques, plasma, and granulocytes on the other. Methods and Results: Samples from patients with femoral atherosclerosis and healthy controls were analyzed on an Apogee A60 Micro-PLUS flow cytometer. Platelet-poor plasma was labeled with lactadherin-FITC, anti-CD14-APC, anti-CD36-PE, and anti-BLTR1-AF700. Eicosapentaenoic acid and arachidonic acid content in different compartments in patients were analyzed using gas chromatography. Compared to controls, patients had lower levels of BLTR1+ MVs (p = 0.007), CD14+BLTR1+ MVs (p = 0.007), and CD14+BLTR1+CD36+ MVs (p = 0.001). Further, in patients CD14+ MVs and CD14+CD36+ MVs correlated inversely with arachidonic acid in granulocytes (r = −0.302, p = 0.039 and r = −0.322, p = 0.028, respectively). Moreover, CD14+CD36+ MVs correlated inversely with arachidonic acid in plasma phospholipids in patients (r = −0.315, p = 0.029), and positively with triglyceride in both patients (r = 0.33, p = 0.019) and controls (r = 0.46, p = 0.022). Conclusion: This is the first study of its kind and thus the results are explorative and only indicative. BLTR1+ MVs and CD14+CD36+ MVs has potential as markers of atherosclerosis pathophysiology, but this needs further investigation.
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Affiliation(s)
- Mathilde Sanden
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Jaco Botha
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Faculty of Medicine, Aalborg University, Aalborg, Denmark
| | | | | | - Erik Berg Schmidt
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Aase Handberg
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Faculty of Medicine, Aalborg University, Aalborg, Denmark
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20
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Min A, Lee YA, Kim KA, Shin MH. BLT1-mediated O-GlcNAcylation is required for NOX2-dependent migration, exocytotic degranulation and IL-8 release of human mast cell induced by Trichomonas vaginalis-secreted LTB 4. Microbes Infect 2018; 20:376-384. [PMID: 29859938 DOI: 10.1016/j.micinf.2018.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 01/15/2018] [Revised: 05/10/2018] [Accepted: 05/23/2018] [Indexed: 12/12/2022]
Abstract
Trichomonas vaginalis is a sexually-transmitted protozoan parasite that causes vaginitis and cervicitis. Although mast cell activation is important for provoking tissue inflammation during infection with parasites, information regarding the signaling mechanisms in mast cell activation and T. vaginalis infection is limited. O-linked N-acetylglucosamine (O-GlcNAc) is a post-translational modification of serine and threonine residues that functions as a critical regulator of intracellular signaling, regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). We investigated if O-GlcNAcylation was associated with mast cell activation induced by T. vaginalis-derived secretory products (TvSP). Modified TvSP collected from live trichomonads treated with the 5-lipooxygenase inhibitor AA861 inhibited migration of mast cells. This result suggested that mast cell migration was caused by stimulation of T. vaginalis-secreted leukotrienes. Using the BLT1 antagonist U75302 or BLT1 siRNA, we found that migration of mast cells was evoked via LTB4 receptor (BLT1). Furthermore, TvSP induced protein O-GlcNAcylation and OGT expression in HMC-1 cells, which was prevented by transfection with BLT1 siRNA. TvSP-induced migration, ROS generation, CD63 expression and IL-8 release were significantly suppressed by pretreatment with OGT inhibitor ST045849 or OGT siRNA. These results suggested that BLT1-mediated OGlcNAcylation was important for mast cell activation during trichomoniasis.
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Affiliation(s)
- Arim Min
- Department of Environmental Medical Biology, Institute of Tropical Medicine, South Korea; Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Young Ah Lee
- Department of Environmental Medical Biology, Institute of Tropical Medicine, South Korea; Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Kyeong Ah Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, South Korea
| | - Myeong Heon Shin
- Department of Environmental Medical Biology, Institute of Tropical Medicine, South Korea; Yonsei University College of Medicine, Seoul 120-752, South Korea.
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21
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Gelfand EW. Importance of the leukotriene B4- BLT1 and LTB4-BLT2 pathways in asthma. Semin Immunol 2018; 33:44-51. [PMID: 29042028 DOI: 10.1016/j.smim.2017.08.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 06/26/2017] [Accepted: 08/06/2017] [Indexed: 12/01/2022]
Abstract
For several decades, the leukotriene pathways have been implicated as playing a central role in the pathophysiology of asthma. The presence and elevation of numerous metabolites in the blood, sputum, and bronchoalveolar lavage fluid from asthmatics or experimental animals adds support to this notion. However, targeting of the leukotriene pathways has had, in general, limited success. The single exception in asthma therapy has been targeting of the cysteinyl leukotriene receptor 1, which clinically has proven effective but only in certain clinical situations. Interference with 5-lipoxygenase has had limited success, in part due to adverse drug effects. The importance of the LTB4-BLT1 pathway in asthma pathogenesis has extensive experimental support and findings, albeit limited, from clinical samples. The LTB4-BLT1 pathway was shown to be important as a neutrophil chemoattractant. Despite observations made more than two decades ago, the LTB4-BLT1 pathway has only recently been shown to exhibit important activities on subsets of T lymphocytes, both as a chemoattractant and on lymphocyte activation, as well as on dendritic cells, the major antigen presenting cell in the lung. The role of BLT2 in asthma remains unclear. Targeting of components of the LTB4-BLT1 pathway offers innovative therapeutic opportunities especially in patients with asthma that remain uncontrolled despite intensive corticosteroid treatment.
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Affiliation(s)
- Erwin W Gelfand
- Division of Cell Biology, Department of Pediatrics, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, United States.
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22
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Sadik CD, Miyabe Y, Sezin T, Luster AD. The critical role of C5a as an initiator of neutrophil-mediated autoimmune inflammation of the joint and skin. Semin Immunol 2018; 37:21-29. [PMID: 29602515 DOI: 10.1016/j.smim.2018.03.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/18/2018] [Accepted: 03/20/2018] [Indexed: 01/15/2023]
Abstract
The deposition of IgG autoantibodies in peripheral tissues and the subsequent activation of the complement system, which leads to the accumulation of the anaphylatoxin C5a in these tissues, is a common hallmark of diverse autoimmune diseases, including rheumatoid arthritis (RA) and pemphigoid diseases (PDs). C5a is a potent chemoattractant for granulocytes and mice deficient in its precursor C5 or its receptor C5aR1 are resistant to granulocyte recruitment and, consequently, to tissue inflammation in several models of autoimmune diseases. However, the mechanism whereby C5a/C5aR regulates granulocyte recruitment in these diseases has remained elusive. Mechanistic studies over the past five years into the role of C5a/C5aR1 in the K/BxN serum arthritis mouse model have provided novel insights into the mechanisms C5a/C5aR1 engages to initiate granulocyte recruitment into the joint. It is now established that the critical actions of C5a/C5aR1 do not proceed in the joint itself, but on the luminal endothelial surface of the joint vasculature, where C5a/C5aR1 mediate the arrest of neutrophils on the endothelium by activating β2 integrin. Then, C5a/C5aR1 induces the release of leukotriene B4 (LTB4) from the arrested neutrophils. The latter, subsequently, initiates by autocrine/paracrine actions via its receptor BLT1 the egress of neutrophils from the blood vessel lumen into the interstitial. Compelling evidence suggests that this C5a/C5aR1-LTB4/BLT1 axis driving granulocyte recruitment in arthritis may represent a more generalizable biological principle critically regulating effector cell recruitment in other IgG autoantibody-induced diseases, such as in pemphigoid diseases. Thus, dual inhibition of C5a and LTB4, as implemented in nature by the lipocalin coversin in the soft-tick Ornithodoros moubata, may constitute a most effective therapeutic principle for the treatment of IgG autoantibody-driven diseases.
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Affiliation(s)
- Christian D Sadik
- Department of Dermatology, Allergy, and Venereology University of Lübeck, 23538, Lübeck, Germany.
| | - Yoshishige Miyabe
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tanya Sezin
- Department of Dermatology, Allergy, and Venereology University of Lübeck, 23538, Lübeck, Germany
| | - Andrew D Luster
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
The high affinity leukotriene B4 receptor, BLT1 mediates chemotaxis of diverse leukocyte subsets to the sites of infection or inflammation. Whereas the pathological functions of LTB4/BLT1 axis in allergy, autoimmunity and cardiovascular disorders are well established; its role in cancer is only beginning to emerge. In this review, we summarize recent findings on LTB4/BLT1 axis enabling distinct outcomes toward tumor progression. In a mouse lung tumor model promoted by silicosis-induced inflammation, genetic deletion of BLT1 attenuated neutrophilic inflammation and tumor promotion. In contrast, in a spontaneous model of intestinal tumorigenesis, absence of BLT1 led to defective mucosal host response, altered microbiota and bacteria dependent colon tumor progression. Furthermore, BLT1 mediated CD8+ T cell recruitment was shown to be essential for initiating anti-tumor immunity in number of xenograft models and is critical for effective PD1 based immunotherapy. BLT2 mediated chemotherapy resistance, tumor promotion and metastasis are also discussed. This new information points to a paradigm shift in our understanding of the LTB4 pathways in cancer.
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24
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Jala VR, Maturu P, Bodduluri SR, Krishnan E, Mathis S, Subbarao K, Wang M, Jenson AB, Proctor ML, Rouchka EC, Knight R, Haribabu B. Leukotriene B 4-receptor-1 mediated host response shapes gut microbiota and controls colon tumor progression. Oncoimmunology 2017; 6:e1361593. [PMID: 29209564 DOI: 10.1080/2162402x.2017.1361593] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/24/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
Inflammation and infection are key promoters of colon cancer but the molecular interplay between these events is largely unknown. Mice deficient in leukotriene B4 receptor1 (BLT1) are protected in inflammatory disease models of arthritis, asthma and atherosclerosis. In this study, we show that BLT1-/- mice when bred onto a spontaneous tumor (ApcMin/+) model displayed an increase in the rate of intestinal tumor development and mortality. A paradoxical increase in inflammation in the tumors from the BLT1-/-ApcMin/+ mice is coincidental with defective host response to infection. Germ-free BLT1-/-ApcMin/+ mice are free from colon tumors that reappeared upon fecal transplantation. Analysis of microbiota showed defective host response in BLT1-/- ApcMin/+ mice reshapes the gut microbiota to promote colon tumor development. The BLT1-/-MyD88-/- double deficient mice are susceptible to lethal neonatal infections. Broad-spectrum antibiotic treatment eliminated neonatal lethality in BLT1-/-MyD88-/- mice and the BLT1-/-MyD88-/-ApcMin+ mice are protected from colon tumor development. These results identify a novel interplay between the Toll-like receptor mediated microbial sensing mechanisms and BLT1-mediated host response in the control of colon tumor development.
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Affiliation(s)
- Venkatakrishna R Jala
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Paramahamsa Maturu
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Sobha R Bodduluri
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Elangovan Krishnan
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Steven Mathis
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Krishnaprasad Subbarao
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Min Wang
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Alfred B Jenson
- Department of Pathology, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Mary L Proctor
- Research Resources Center, University of Louisville Health Sciences Center, Louisville, KY, USA
| | - Eric C Rouchka
- Department of Computer Engineering & Computer Science, Speed School of Engineering, University of Louisville, Louisville, KY, USA
| | - Rob Knight
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, USA
| | - Bodduluri Haribabu
- James Graham Brown Cancer Center, University of Louisville Health Sciences Center, Louisville, KY, USA.,Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY, USA
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25
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Chen X, Stout S, Mueller U, Boykow G, Visconti R, Siliphaivanh P, Spencer K, Presland J, Kavana M, Basso AD, McLaren DG, Myers RW. Label-Free, LC-MS-Based Assays to Quantitate Small-Molecule Antagonist Binding to the Mammalian BLT1 Receptor. SLAS Discov 2017; 22:1131-1141. [PMID: 28763622 DOI: 10.1177/2472555217719748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have developed and validated label-free, liquid chromatography-mass spectrometry (LC-MS)-based equilibrium direct and competition binding assays to quantitate small-molecule antagonist binding to recombinant human and mouse BLT1 receptors expressed in HEK 293 cell membranes. Procedurally, these binding assays involve (1) equilibration of the BLT1 receptor and probe ligand, with or without a competitor; (2) vacuum filtration through cationic glass fiber filters to separate receptor-bound from free probe ligand; and (3) LC-MS analysis in selected reaction monitoring mode for bound probe ligand quantitation. Two novel, optimized probe ligands, compounds 1 and 2, were identified by screening 20 unlabeled BLT1 antagonists for direct binding. Saturation direct binding studies confirmed the high affinity, and dissociation studies established the rapid binding kinetics of probe ligands 1 and 2. Competition binding assays were established using both probe ligands, and the affinities of structurally diverse BLT1 antagonists were measured. Both binding assay formats can be executed with high specificity and sensitivity and moderate throughput (96-well plate format) using these approaches. This highly versatile, label-free method for studying ligand binding to membrane-associated receptors should find broad application as an alternative to traditional methods using labeled ligands.
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Affiliation(s)
- Xun Chen
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Steven Stout
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Uwe Mueller
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - George Boykow
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Richard Visconti
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Phieng Siliphaivanh
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Kerrie Spencer
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Jeremy Presland
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Michael Kavana
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Andrea D Basso
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - David G McLaren
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
| | - Robert W Myers
- Discovery, Preclinical and Early Development, Merck & Co., Kenilworth, NJ, USA
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26
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Min A, Lee YA, Kim KA, El-Benna J, Shin MH. SNAP23-Dependent Surface Translocation of Leukotriene B4 (LTB4) Receptor 1 Is Essential for NOX2-Mediated Exocytotic Degranulation in Human Mast Cells Induced by Trichomonas vaginalis-Secreted LTB4. Infect Immun 2017; 85:e00526-16. [PMID: 27795355 DOI: 10.1128/IAI.00526-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/16/2016] [Indexed: 11/20/2022] Open
Abstract
Trichomonas vaginalis is a sexually transmitted parasite that causes vaginitis in women and itself secretes lipid mediator leukotriene B4 (LTB4). Mast cells are important effector cells of tissue inflammation during infection with parasites. Membrane-bridging SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complexes are critical for fusion during exocytosis. Although T. vaginalis-derived secretory products (TvSP) have been shown to induce exocytosis in mast cells, information regarding the signaling mechanisms between mast cell activation and TvSP is limited. In this study, we found that SNAP23-dependent surface trafficking of LTB4 receptor 1 (BLT1) is required for nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2)-mediated exocytotic degranulation of mast cells induced by TvSP. First, stimulation with TvSP induced exocytotic degranulation and reactive oxygen species (ROS) generation in HMC-1 cells. Next, TvSP-induced ROS generation and exocytosis were strongly inhibited by transfection of BLT1 small interfering RNA (siRNA). TvSP induced trafficking of BLT1 from the cytosol to the plasma membrane. We also found that knockdown of SNAP23 abrogated TvSP-induced ROS generation, exocytosis, and surface trafficking of BLT1 in HMC-1 cells. By coimmunoprecipitation, there was a physical interaction between BLT1 and SNAP23 in TvSP-stimulated HMC-1 cells. Taken together, our results suggest that SNAP23-dependent surface trafficking of BLT1 is essential for exocytosis in human mast cells induced by T. vaginalis-secreted LTB4 Our data collectively demonstrate a novel regulatory mechanism for SNAP23-dependent mast cell activation of T. vaginalis-secreted LTB4 involving surface trafficking of BLT1. These results can help to explain how the cross talk mechanism between parasite and host can govern deliberately tissue inflammatory responses.
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27
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Jeon WK, Choi J, Park SJ, Jo EJ, Lee YK, Lim S, Kim JH, Letterio JJ, Liu F, Kim SJ, Kim BC. The proinflammatory LTB4/ BLT1 signal axis confers resistance to TGF-β1-induced growth inhibition by targeting Smad3 linker region. Oncotarget 2015; 6:41650-66. [PMID: 26497676 DOI: 10.18632/oncotarget.6146] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 09/30/2015] [Indexed: 01/07/2023] Open
Abstract
Leukotriene B4 (LTB4) is a potent pro-inflammatory eicosanoid that is derived from arachidonic acid, and its signaling is known to have a tumor-promoting role in several cancer types. In this study, we investigated whether enhanced LTB4 signaling confers resistance to the cytostatic transforming growth factor-β1 (TGF-β1) response. We found that LTB4 pretreatment or ectopic expression of BLT1, a high affinity LTB4 receptor, fully abrogated TGF-β1-induced cell cycle arrest and expression of p15INK4B and p27KIP1. Mechanism study revealed that LTB4-mediated suppression of TGF-β1-induced Smad3 activation and growth inhibition was due to enhanced phosphorylation of Smad3 linker region (pSmad3L) through activation of BLT1-NAD(P)H oxidase (NOX)-reactive oxygen species (ROS)-epidermal growth factor receptor (EGFR)-phosphatidylinositol 3-kinase (PI3-K)-extracellular signal-activated kinase1/2 (ERK1/2)-linked signaling cascade. Furthermore, the LTB4/BLT1 signaling pathway leading to pSmad3L was constitutively activated in breast cancer cells and was correlated with TGF-β1-resistant growth of the cells in vitro and in vivo. In human breast cancer tissues, the expression level of pSmad3L (Thr179) had a positive correlation with BLT1 expression. Collectively, our data demonstrate for the first time that the induction of pSmad3L through BLT1-NOX-ROS-EGFR-PI3K-ERK1/2 signaling pathway is a key mechanism by which LTB4 blocks the anti-proliferative responses of TGF-β1, providing a novel mechanistic insight into the connection between enhanced inflammatory signal and cancer cell growth.
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28
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Hansen AK, Indrevik JT, Figenschau Y, Martinez-Zubiaurre I, Sveinbjörnsson B. Human articular chondrocytes express functional leukotriene B4 receptors. J Anat 2015; 226:268-77. [PMID: 25677035 DOI: 10.1111/joa.12275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2014] [Indexed: 12/11/2022] Open
Abstract
Leukotriene B4 (LTB4) is a potent chemoattractant associated with the development of osteoarthritis (OA), while its receptors BLT1 and BLT2 have been found in synovium and subchondral bone. In this study, we have investigated whether these receptors are also expressed by human cartilage cells and their potential effects on cartilage cells. The expression of LTB4 receptors in native tissue and cultured cells was assessed by immunohistochemistry, immunocytochemistry, polymerase chain reaction (PCR) and electron microscopy. The functional significance of the LTB4 receptor expression was studied by Western blotting, using phospho-specific antibodies in the presence or absence of receptor antagonists. In further studies, the secretion of pro-inflammatory cytokines, growth factors and metalloproteinases by LTB4-stimulated chondrocytes was measured by multiplex protein assays. The effects of LTB4 in cartilage signature gene expression in cultured cells were assessed by quantitative PCR, whereas the LTB4-promoted matrix synthesis was determined using 3D pellet cultures. Both receptors were present in cultured chondrocytes, as was confirmed by immunolabelling and PCR. The relative quantification by PCR demonstrated a higher expression of the receptors in cells from healthy joints compared with OA cases. The stimulation of cultured chondrocytes with LTB4 resulted in a phosphorylation of downstream transcription factor Erk 1/2, which was reduced after blocking BLT1 signalling. No alteration in the secretion of cytokine and metalloproteinases was recorded after challenging cultured cells with LTB4; likewise, cartilage matrix gene expression and 3D tissue synthesis were unaffected. Chondrocytes express BLT1 and BLT2 receptors, and LTB4 activates the downstream Erk 1/2 pathway by engaging the high-affinity receptor BLT1. However, any putative role in cartilage biology could not be revealed, and remains to be clarified.
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Affiliation(s)
- Ann Kristin Hansen
- Department of Orthopaedic and Plastic Surgery, University Hospital of North Norway, Tromsø, Norway; Bone and Joint Research Group, Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway
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29
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Sharma RK, Chheda ZS, Jala VR, Haribabu B. Regulation of cytotoxic T-Lymphocyte trafficking to tumors by chemoattractants: implications for immunotherapy. Expert Rev Vaccines 2014; 14:537-49. [PMID: 25482400 DOI: 10.1586/14760584.2015.982101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cancer immunotherapy has recently emerged as an important treatment modality. FDA approval of provenge, ipilimumab and pembrolizumab has started to deliver on the long awaited promise of cancer immunotherapy. Many new modalities of immunotherapies targeting cytotoxic T lymphocytes (CTLs) responses, such as adoptive cell therapies and vaccines, are in advanced clinical trials. In all these immunotherapies, migration of CTLs to the tumor site is a critical step for achieving therapeutic efficacy. However, inefficient infiltration of activated CTLs into established tumors is increasingly being recognized as one of the major hurdles limiting efficacy. Mechanisms that control migration of CTLs to tumors are poorly defined. In this review, the authors discuss the chemoattractants and their receptors that have been implicated in endogenous- or immunotherapy-induced CTL recruitment to tumors and the potential for targeting these pathways for therapeutic efficacy.
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Affiliation(s)
- Rajesh K Sharma
- James Graham Brown Cancer Center, University of Louisville Health Sciences, Louisville, KY 40202, USA
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30
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Li XJ, Fu HY, Yi WJ, Zhao YJ, Wang J, Li JB, Wang JF, Deng XM. Dual role of leukotriene B4 receptor type 1 in experimental sepsis. J Surg Res 2014; 193:902-8. [PMID: 25439504 DOI: 10.1016/j.jss.2014.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 05/06/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND The controversial results from different studies suggested that leukocyte recruitment mediated by leukotriene B4 (LTB4) and its receptor might improve pathogen clearance, but might also aggravate organ injury during sepsis. The present study was performed to compare the effect of BLT1 ligand LTB4 and its antagonist U-75302 on the development of sepsis. METHODS Sepsis in mice was induced by cecal ligation and puncture (CLP). The mice were allocated into sham group, CLP group, U-75302 group, and LTB4 group. In the latter three groups, CLP mice were treated by intraperitoneal saline, U-75302, and LTB4, respectively. Their effect on the progression of sepsis were compared by histopathologic tests, level of systemic cytokines, counts of immune cells and bacterial clearance, and survival rate. RESULTS The histopathologic tests showed that U-75302 attenuated lung injury, whereas LTB4 aggravated liver injury. LTB4 increased the plasma levels of interleukin-6, tumor necrosis factor-α, and U-75302 increased the level of plasma interleukin-10. LTB4 increased whereas U-75302 reduced the neutrophil numbers in the peritoneal lavage fluid. LTB4 also increased the number of peritoneal and splenic CD4(+) and CD8(+) T cells. Bacterial clearance in blood and peritoneal lavage fluid was significantly enhanced in the LTB4 group. Both U-75302 and LTB4 did not change the survival rate significantly compared with vehicle, but mortality in the LTB4 group was significantly higher than in the U-75302 group. Dose response analyses were also performed to compare the effect of U-75302 and LTB4 at different doses. Different doses of both agents did not influence the survival rate of CLP mice. CONCLUSIONS U-75302 attenuates sepsis-induced organ injury, whereas LTB4 increases the leukocyte recruitment toward infection site, but LTB4 showed a more lethal effect than U-75302 during polymicrobial sepsis.
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Affiliation(s)
- Xiu-juan Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Hong-yu Fu
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Wen-jing Yi
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Yan-jun Zhao
- Department of Anesthesiology and Intensive Care, Shanghai Ninth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Jun Wang
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Jin-bao Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Jia-feng Wang
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Xiao-ming Deng
- Department of Anesthesiology and Intensive Care, Changhai Hospital, Second Military Medical University, Shanghai, China.
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31
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Abstract
Leukotriene B4 (LTB4), a potent lipid mediator of inflammation derived from arachidonic acid through the action of 5-lipoxygenase, has been implicated in the pathophysiology of several inflammatory diseases, including asthma and chronic obstructive pulmonary disease. A high-affinity LTB4 receptor BLT1 has been shown to exert proinflammatory roles. A cyclooxygenase metabolite, 12(S)-hydroxyheptadeca-5Z, 8E, 10E-trienoic acid (12-HHT), is an endogenous ligand for BLT2, a low-affinity LTB4 receptor. The recent study indicated that BLT2 has a protective role in allergic airway inflammation, suggesting different functions between BLT1 and BLT2 in the pathogenesis of asthma. Selective BLT1 antagonists may have a potential therapeutic application in patients with asthma, and BLT2 may represent a novel therapeutic target for lung diseases.
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Affiliation(s)
- Masaki Watanabe
- Department of Pulmonary Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8520, Japan
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32
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Ohkubo H, Ito Y, Minamino T, Mishima T, Hirata M, Hosono K, Shibuya M, Yokomizo T, Shimizu T, Watanabe M, Majima M. Leukotriene B4 type-1 receptor signaling promotes liver repair after hepatic ischemia/reperfusion injury through the enhancement of macrophage recruitment. FASEB J 2013; 27:3132-43. [PMID: 23629862 DOI: 10.1096/fj.13-227421] [Citation(s) in RCA: 19] [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] [Indexed: 01/01/2023]
Abstract
Recruited macrophages play a critical role in liver repair after acute liver injury. Leukotriene B4 (LTB4) is a potent chemoattractant for macrophages. In this study, we investigated the role of LTB4 receptor type 1 (BLT1) in liver repair during hepatic ischemia/reperfusion (I/R) injury. BLT1-knockout mice (BLT1(-/-)) or their wild-type counterparts (WT) were subjected to partial hepatic I/R. Compared with WT, BLT1(-/-) exhibited delayed liver repair and hepatocyte proliferation accompanied by a 70% reduction in the recruitment of macrophages and a 70-80% attenuation in hepatic expression of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1). Disruption of BLT1 signaling also reduced the expression of EGF by 67% on recruited macrophages expressing VEGFR1 in the injured liver. Treatment of WT mice with an EGF-neutralizing antibody delayed liver repair and reduced macrophage recruitment, compared with control immunoglobulin G (IgG). BLT1 signaling enhanced the expression of VEGF, VEGFR1, and EGF in isolated peritoneal macrophages in vitro. These results indicate that BLT1 signaling plays a role in liver repair after hepatic I/R through enhanced expression of EGF in recruited macrophages and that the development of a specific agonist for BLT1 could be useful for liver recovery from acute liver injury.
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Affiliation(s)
- Hirotoki Ohkubo
- Department of Pharmacology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara Kanagawa, 252-0374, Japan
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