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Li X, Chen G, Wang F, Guo X, Zhang R, Liu P, Dong L, Yu W, Wang H, Wang H, Yu J. Oncogenic PIK3CA recruits myeloid-derived suppressor cells to shape the immunosuppressive tumour microenvironment in luminal breast cancer through the 5-lipoxygenase-dependent arachidonic acid pathway. Clin Transl Med 2023; 13:e1483. [PMID: 37965796 PMCID: PMC10646754 DOI: 10.1002/ctm2.1483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Oncogenic PIK3CA mutations (PIK3CAmut ) frequently occur in a higher proportion in luminal breast cancer (LBC), especially in refractory advanced cases, and are associated with changes in tumour cellular metabolism. Nevertheless, its effect on the progression of the immune microenvironment (TIME) within tumours and vital molecular events remains veiled. METHODS Multiplex immunohistochemistry (mIHC) and single-cell mass cytometry (CyTOF) was used to describe the landscape of TIME in PIK3CAmut LBC. The PIK3CA mutant cell lines were established using CRISPER/Cas9 system. The gene expression levels, protein secretion and activity of signaling pathways were measured by real-time RT-PCR, ELISA, immunofluorescence staining or western blotting. GSEA analysis, transwell chemotaxis assay, live cell imaging, flow cytometry metabolite analysis targeting arachidonic acid, Dual-luciferase reporter assay, and Chromatin immunoprecipitation assay were used to investigate the underlying function and mechanism of the PI3K/5-LOX/LTB4 axis. RESULTS PIK3CAmut LBC cells can induce an immunosuppressive TIME by recruiting myeloid-derived suppressor cells (MDSCs) and excluding cytotoxic T cells via the arachidonic acid (AA) metabolism pathway. Mechanistically, PIK3CAmut activates the transcription of 5-lipoxygenase (5-LOX) in a STAT3-dependent manner, which in turn directly results in high LTB4 production, binding to BLT2 on MDSCs and promoting their infiltration. Since a suppressive TIME is a critical barrier for the success of cancer immunotherapy, the strategies that can convert "cold" tumours into "hot" tumours were compared. Targeted therapy against the PI3K/5-LOX/LTB4 axis synergizing with immune checkpoint blockade (ICB) therapy achieved dramatic shrinkage in vivo. CONCLUSIONS The results emphasize that PIK3CAmut can induce immune evasion by recruiting MDSCs through the 5-LOX-dependent AA pathway, and combination targeted therapy with ICB may provide a promising treatment option for refractory advanced LBC patients.
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Affiliation(s)
- Xingchen Li
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
- Department of Thyroid and Neck, Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouChina
| | - Guidong Chen
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
| | - Fanchen Wang
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
| | - Xiaojing Guo
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
- Department of Breast Pathology and Lab, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjinChina
| | - Rui Zhang
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
| | - Pengpeng Liu
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
| | - Li Dong
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
| | - Wenwen Yu
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Department of Immunology, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center for Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
| | - Huan Wang
- College of Life SciencesNankai UniversityTianjinChina
| | - Hailong Wang
- Laboratory of Cancer Cell Biology, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center for Caner, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Prevention and TherapyTianjinChina
| | - Jinpu Yu
- Cancer Molecular Diagnostics Core, Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center of Cancer, Tianjin's Clinical Research Center for CancerTianjinChina
- Key Laboratory of Cancer Immunology and BiotherapyTianjinChina
- Key Laboratory of Breast Cancer Prevention and TherapyTianjin Medical University, Ministry of EducationTianjinChina
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2
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Lin Y, Cai Q, Chen Y, Shi T, Liu W, Mao L, Deng B, Ying Z, Gao Y, Luo H, Yang X, Huang X, Shi Y, He R. CAFs shape myeloid-derived suppressor cells to promote stemness of intrahepatic cholangiocarcinoma through 5-lipoxygenase. Hepatology 2022; 75:28-42. [PMID: 34387870 DOI: 10.1002/hep.32099] [Citation(s) in RCA: 84] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 07/16/2021] [Accepted: 08/02/2021] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIMS We previously demonstrated that cancer-associated fibroblasts (CAFs) promote tumor growth through recruitment of myeloid-derived suppressor cells (MDSCs). 5-lipoxygenase (5-LO) is highly expressed in myeloid cells and is critical for synthesizing leukotriene B4 (LTB4), which is involved in tumor progression by activating its receptor leukotriene B4 receptor type 2 (BLT2). In this study, we investigated whether and how CAFs regulate MDSC function to enhance cancer stemness, the driving force of the cancer aggressiveness and chemotherapy refractoriness, in highly desmoplastic intrahepatic cholangiocarcinoma (ICC). APPROACH AND RESULTS RNA-sequencing analysis revealed enriched metabolic pathways but decreased inflammatory pathways in cancer MDSCs compared with blood MDSCs from patients with ICC. Co-injection of ICC patient-derived CAFs promoted cancer stemness in an orthotopic ICC model, which was blunted by MDSC depletion. Conditioned media (CM) from CAF-educated MDSCs drastically promoted tumorsphere formation efficiency and stemness marker gene expression in ICC cells. CAF-CM stimulation increased expression and activity of 5-LO in MDSCs, while 5-LO inhibitor impaired the stemness-enhancing capacity of MDSCs in vitro and in vivo. Furthermore, IL-6 and IL-33 primarily expressed by CAFs mediated hyperactivated 5-LO metabolism in MDSCs. We identified the LTB4-BLT2 axis as the critical downstream metabolite signaling of 5-LO in promoting cancer stemness, as treatment with LTB4 was elevated in CAF-educated MDSCs, or blockade of BLT2 (which was preferentially expressed in stem-like ICC cells) significantly reduced stemness-enhancing effects of CAF-educated MDSCs. Finally, BLT2 blockade augmented chemotherapeutic efficacy in ICC patient-derived xenograft models. CONCLUSIONS Our study reveals a role for CAFs in orchestrating the optimal cancer stemness-enhancing microenvironment by educating MDSCs, and suggests the 5-LO/LTB4-BLT2 axis as promising therapeutic targets for ICC chemoresistance by targeting cancer stemness.
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Affiliation(s)
- Yuli Lin
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qian Cai
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yu Chen
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Tiancong Shi
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Weiren Liu
- Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Shanghai, China
| | - Li Mao
- Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Shanghai, China
| | - Bo Deng
- Division of Nephrology, School of Medicine, Shanghai Ninth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Zhen Ying
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yuan Gao
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Haoyang Luo
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Xuguang Yang
- Department of Oncology, Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaowu Huang
- Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Shanghai, China
| | - Yinghong Shi
- Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Shanghai, China
| | - Rui He
- Department of Immunology and Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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3
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Liu M, Yan M, He J, Lv H, Chen Z, Peng L, Cai W, Yao F, Chen C, Shi L, Zhang K, Zhang X, Wang DW, Wang L, Zhu Y, Ai D. Macrophage MST1/2 Disruption Impairs Post-Infarction Cardiac Repair via LTB4. Circ Res 2021; 129:909-926. [PMID: 34515499 DOI: 10.1161/circresaha.121.319687] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
[Figure: see text].
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Differentiation, Myelomonocytic/genetics
- Antigens, Differentiation, Myelomonocytic/metabolism
- Chemokine CCL2/genetics
- Chemokine CCL2/metabolism
- Chemokine CCL4/genetics
- Chemokine CCL4/metabolism
- Chemokine CXCL2/metabolism
- Female
- Leukotriene B4/metabolism
- Lipoxygenase/metabolism
- Macrophages/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Myocardial Infarction/metabolism
- Myocardium/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Leukotriene B4/antagonists & inhibitors
- Receptors, Leukotriene B4/metabolism
- Serine-Threonine Kinase 3/genetics
- Serine-Threonine Kinase 3/metabolism
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Affiliation(s)
- Mingming Liu
- Tianjin Key Laboratory of Ion and Molecular Function of Cardiovascular Diseases, Tianjin Institute of Cardiology, State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), the Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics (M.L., M.Y., H.L., D.A.), Tianjin Medical University
- Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital (M.L.)
| | - Meng Yan
- Tianjin Key Laboratory of Ion and Molecular Function of Cardiovascular Diseases, Tianjin Institute of Cardiology, State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), the Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics (M.L., M.Y., H.L., D.A.), Tianjin Medical University
- The First Affiliated Hospital of Soochow University Department of Pathology, Soochow University, Suzhou (M.Y.)
| | - Jinlong He
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Huizhen Lv
- Tianjin Key Laboratory of Ion and Molecular Function of Cardiovascular Diseases, Tianjin Institute of Cardiology, State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), the Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics (M.L., M.Y., H.L., D.A.), Tianjin Medical University
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Zhipeng Chen
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Liyuan Peng
- Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan (L.P., C.C., D.-W.W.)
| | - Wenbin Cai
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Fang Yao
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College (F.Y., L.W.)
| | - Chen Chen
- Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan (L.P., C.C., D.-W.W.)
| | - Lei Shi
- Biochemistry and Molecular Biology, School of Basic Medical Sciences (L.S., K.Z.), Tianjin Medical University
| | - Kai Zhang
- Biochemistry and Molecular Biology, School of Basic Medical Sciences (L.S., K.Z.), Tianjin Medical University
| | - Xu Zhang
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Dao-Wen Wang
- Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan (L.P., C.C., D.-W.W.)
| | - Li Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College (F.Y., L.W.)
| | - Yi Zhu
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
| | - Ding Ai
- Tianjin Key Laboratory of Ion and Molecular Function of Cardiovascular Diseases, Tianjin Institute of Cardiology, State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), the Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics (M.L., M.Y., H.L., D.A.), Tianjin Medical University
- Physiology and Pathophysiology (J.H., H.L., Z.C., W.C., X.Z., Y.Z., D.A.), Tianjin Medical University
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4
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Romp E, Arakandy V, Fischer J, Wolz C, Siegmund A, Löffler B, Tuchscherr L, Werz O, Garscha U. Exotoxins from Staphylococcus aureus activate 5-lipoxygenase and induce leukotriene biosynthesis. Cell Mol Life Sci 2020; 77:3841-3858. [PMID: 31807813 PMCID: PMC11105070 DOI: 10.1007/s00018-019-03393-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/14/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022]
Abstract
Massive neutrophil infiltration is an early key event in infectious inflammation, accompanied by chemotactic leukotriene (LT)B4 generation. LTB4 biosynthesis is mediated by 5-lipoxygenase (5-LOX), but which pathogenic factors cause 5-LOX activation during bacterial infections is elusive. Here, we reveal staphylococcal exotoxins as 5-LOX activators. Conditioned medium of wild-type Staphylococcus aureus but not of exotoxin-deficient strains induced 5-LOX activation in transfected HEK293 cells. Two different staphylococcal exotoxins mimicked the effects of S. aureus-conditioned medium: (1) the pore-forming toxin α-hemolysin and (2) amphipathic α-helical phenol-soluble modulin (PSM) peptides. Interestingly, in human neutrophils, 5-LOX activation was exclusively evoked by PSMs, which was prevented by the selective FPR2/ALX receptor antagonist WRW4. 5-LOX activation by PSMs was confirmed in vivo as LT formation in infected paws of mice was impaired in response to PSM-deficient S. aureus. Conclusively, exotoxins from S. aureus are potent pathogenic factors that activate 5-LOX and induce LT formation in neutrophils.
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Affiliation(s)
- Erik Romp
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Vandana Arakandy
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Jana Fischer
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, 72076, Tuebingen, Germany
| | - Anke Siegmund
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Oliver Werz
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Ulrike Garscha
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany.
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5
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He Z, Tao D, Xiong J, Lou F, Zhang J, Chen J, Dai W, Sun J, Wang Y. Phosphorylation of 5-LOX: The Potential Set-point of Inflammation. Neurochem Res 2020; 45:2245-2257. [PMID: 32671628 DOI: 10.1007/s11064-020-03090-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/11/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022]
Abstract
Inflammation secondary to tissue injuries serves as a double-edged sword that determines the prognosis of tissue repair. As one of the most important enzymes controlling the inflammation process by producing leukotrienes, 5-lipoxygenase (5-LOX, also called 5-LO) has been one of the therapeutic targets in regulating inflammation for a long time. Although a large number of 5-LOX inhibitors have been explored, only a few of them can be applied clinically. Surprisingly, phosphorylation of 5-LOX reveals great significance in regulating the subcellular localization of 5-LOX, which has proven to be an important mechanism underlying the enzymatic activities of 5-LOX. There are at least three phosphorylation sites in 5-LOX jointly to determine the final inflammatory outcomes, and adjustment of phosphorylation of 5-LOX at different phosphorylation sites brings hope to provide an unrecognized means to regulate inflammation. The present review intends to shed more lights into the set-point-like mechanisms of phosphorylation of 5-LOX and its possible clinical application by summarizing the biological properties of 5-LOX, the relationship of 5-LOX with neurodegenerative diseases and brain injuries, the phosphorylation of 5-LOX at different sites, the regulatory effects and mechanisms of phosphorylated 5-LOX upon inflammation, as well as the potential anti-inflammatory application through balancing the phosphorylation-depended set-point.
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Affiliation(s)
- Zonglin He
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China.,Faculty of Medicine, International school, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Di Tao
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China.,Faculty of Medicine, International school, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Jiaming Xiong
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Fangfang Lou
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Jiayuan Zhang
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Jinxia Chen
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Weixi Dai
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China.,Faculty of Medicine, International school, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Jing Sun
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China
| | - Yuechun Wang
- Department of Physiology, Basic Medical School, Jinan University, Huangpu Avenue 601, Tianhe District, Guangzhou, Guangdong Province, China.
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6
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Schmider AB, Bauer NC, Sunwoo H, Godin MD, Ellis GE, Lee JT, Nigrovic PA, Soberman RJ. Two- and three-color STORM analysis reveals higher-order assembly of leukotriene synthetic complexes on the nuclear envelope of murine neutrophils. J Biol Chem 2020; 295:5761-5770. [PMID: 32152223 PMCID: PMC7186161 DOI: 10.1074/jbc.ra119.012069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/24/2020] [Indexed: 11/06/2022] Open
Abstract
Over the last several years it has become clear that higher order assemblies on membranes, exemplified by signalosomes, are a paradigm for the regulation of many membrane signaling processes. We have recently combined two-color direct stochastic optical reconstruction microscopy (dSTORM) with the (Clus-DoC) algorithm that combines cluster detection and colocalization analysis to observe the organization of 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) into higher order assemblies on the nuclear envelope of mast cells; these assemblies were linked to leukotriene (LT) C4 production. In this study we investigated whether higher order assemblies of 5-LO and FLAP included cytosolic phospholipase A2 (cPLA2) and were linked to LTB4 production in murine neutrophils. Using two- and three-color dSTORM supported by fluorescence lifetime imaging microscopy we identified higher order assemblies containing 40 molecules (median) (IQR: 23, 87) of 5-LO, and 53 molecules (62, 156) of FLAP monomer. 98 (18, 154) molecules of cPLA2 were clustered with 5-LO, and 77 (33, 114) molecules of cPLA2 were associated with FLAP. These assemblies were tightly linked to LTB4 formation. The activation-dependent close associations of cPLA2, FLAP, and 5-LO in higher order assemblies on the nuclear envelope support a model in which arachidonic acid is generated by cPLA2 in apposition to FLAP, facilitating its transfer to 5-LO to initiate LT synthesis.
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Affiliation(s)
- Angela B Schmider
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129
| | - Nicholas C Bauer
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129
| | - Hongjae Sunwoo
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Matthew D Godin
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129
| | - Giorgianna E Ellis
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114; Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
| | - Peter A Nigrovic
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Roy J Soberman
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129.
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7
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Saeki K, Yokomizo T. Identification, signaling, and functions of LTB 4 receptors. Semin Immunol 2018; 33:30-36. [PMID: 29042026 DOI: 10.1016/j.smim.2017.07.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 05/02/2017] [Accepted: 07/26/2017] [Indexed: 10/18/2022]
Abstract
Leukotriene B4 (LTB4), a lipid mediator produced from arachidonic acid, is a chemoattractant for inflammatory leukocytes. We identified two receptors for LTB4, the high-affinity receptor BLT1 and the low-affinity receptor BLT2. BLT1 is expressed in various subsets of leukocytes, and analyses of BLT1-deficient mice revealed that the LTB4/BLT1 axis enhances leukocyte recruitment to infected sites, and is involved in the elimination of pathogens. Hyperactivation of the LTB4/BLT1 axis induces acute and chronic inflammation, resulting in various inflammatory diseases. BLT2 was originally identified as a low-affinity receptor for LTB4, and we later identified 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (12-HHT) as a high-affinity ligand for BLT2. BLT2 is highly expressed in epithelial cells in various tissues including intestine and skin. Large quantities of 12-HHT are produced by activated platelets during skin injury, and activation of BLT2 on epidermal keratinocytes accelerates skin wound healing by enhancing cell migration. BLT2 signaling also enhances cell-cell junctions, protectes against transepidermal water loss, and preventes entry of environmental substances into the body.
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Affiliation(s)
- Kazuko Saeki
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.
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8
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Subramanian BC, Majumdar R, Parent CA. The role of the LTB 4-BLT1 axis in chemotactic gradient sensing and directed leukocyte migration. Semin Immunol 2018; 33:16-29. [PMID: 29042024 DOI: 10.1016/j.smim.2017.07.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 06/07/2017] [Accepted: 07/13/2017] [Indexed: 12/11/2022]
Abstract
Directed leukocyte migration is a hallmark of inflammatory immune responses. Leukotrienes are derived from arachidonic acid and represent a class of potent lipid mediators of leukocyte migration. In this review, we summarize the essential steps leading to the production of LTB4 in leukocytes. We discuss the recent findings on the exosomal packaging and transport of LTB4 in the context of chemotactic gradients formation and regulation of leukocyte recruitment. We also discuss the dynamic roles of the LTB4 receptors, BLT1 and BLT2, in mediating chemotactic signaling in leukocytes and contrast them to other structurally related leukotrienes that bind to distinct GPCRs. Finally, we highlight the specific roles of the LTB4-BLT1 axis in mediating signal-relay between chemotaxing neutrophils and its potential contribution to a wide variety of inflammatory conditions including tumor progression and metastasis, where LTB4 is emerging as a key signaling component.
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Affiliation(s)
- Bhagawat C Subramanian
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States.
| | - Ritankar Majumdar
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
| | - Carole A Parent
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
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9
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Ball AK, Beilstein K, Wittmann S, Sürün D, Saul MJ, Schnütgen F, Flamand N, Capelo R, Kahnt AS, Frey H, Schaefer L, Marschalek R, Häfner AK, Steinhilber D. Characterization and cellular localization of human 5-lipoxygenase and its protein isoforms 5-LOΔ13, 5-LOΔ4 and 5-LOp12. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:561-571. [PMID: 28257804 DOI: 10.1016/j.bbalip.2017.02.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/06/2017] [Accepted: 02/24/2017] [Indexed: 01/29/2023]
Abstract
Human 5-lipoxygenase (5-LO-WT) initiates the leukotriene (LT) biosynthesis. LTs play an important role in diseases like asthma, atherosclerosis and in many types of cancer. In this study, we investigated the 5-LO isoforms 5-LO∆13, 5-LO∆4 and 5-LOp12, lacking the exons 13, 4 or a part of exon 12, respectively. We were able to detect the mRNA of the isoforms 5-LO∆13 and 5-LOp12 in B and T cell lines as well as in primary B and T cells and monocytes. Furthermore, we found that expression of 5-LO and particularly of the 5-LO∆13 and 5-LOp12 isoforms is increased in monocytes from patients with rheumatoid arthritis and sepsis. Confocal microscopy of HEK293T cells stably transfected with tagged 5-LO-WT and/or the isoforms revealed that 5-LO-WT is localized in the nucleus whereas all isoforms are located in the cytosol. Additionally, all isoforms are catalytically inactive and do not seem to influence the specific activity of 5-LO-WT. S271A mutation in 5-LO-WT and treatment of the cells with sorbitol or KN-93/SB203580 changes the localization of the WT enzyme to the cytosol. Despite colocalization with the S271A mutant, the isoforms did not affect LT biosynthesis. Analysis of the phosphorylation pattern of 5-LO-WT and all the isoforms revealed that 5-LOp12 and 5-LO∆13 are highly phosphorylated at Ser271 and 5-LOp12 at Ser523. Furthermore, coexpression of the isoforms inhibited or stimulated 5-LO-WT expression in transiently and stably transfected HEK293T cells suggesting that the isoforms have other functions than canonical LT biosynthesis.
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Affiliation(s)
- Ann-Katrin Ball
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Kim Beilstein
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Sandra Wittmann
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Duran Sürün
- Department of Molecular Hematology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Meike J Saul
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Frank Schnütgen
- Department of Molecular Hematology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Nicolas Flamand
- Centre de recherche de l'IUCPQ, Département de Médecine et Faculté de Médecine, Université Laval, Québec, QC G1V 4G5, Canada
| | - Ricardo Capelo
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Astrid S Kahnt
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Helena Frey
- General Pharmacology and Toxicology, Goethe-University Frankfurt, Theodor-Stern Kai 7, 60590 Frankfurt, Germany
| | - Liliana Schaefer
- General Pharmacology and Toxicology, Goethe-University Frankfurt, Theodor-Stern Kai 7, 60590 Frankfurt, Germany
| | - Rolf Marschalek
- Institute of Pharmaceutical Biology, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Ann-Kathrin Häfner
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
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10
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Giménez-Bastida JA, Shibata T, Uchida K, Schneider C. Roles of 5-lipoxygenase and cyclooxygenase-2 in the biosynthesis of hemiketals E 2 and D 2 by activated human leukocytes. FASEB J 2017; 31:1867-1878. [PMID: 28096231 DOI: 10.1096/fj.201601136r] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/03/2017] [Indexed: 11/11/2022]
Abstract
The 2 hemiketal (HK) eicosanoids HKD2 and HKE2 are the major products of the biosynthetic crossover of the 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) pathways. HKs result from the rearrangement of a di-endoperoxide intermediate formed in the COX-2-dependent oxygenation of 5S-hydroxyeicosatetraenoic acid (5S-HETE). We analyzed HK biosynthesis in human leukocytes stimulated ex vivo and defined the biosynthetic roles of 5-LOX and COX-2, using inhibitors and incubations with exogenous substrates. Activation of leukocytes with LPS followed by treatment with the calcium ionophore A23187 resulted in the formation of PGE2, 5-HETE, and LTB4 as the principal metabolites of COX-2 and 5-LOX, respectively. The formation of HKD2 and HKE2 was highest after 15 min LPS treatment, and at that time, levels were similar to PGE2, but less than 5-HETE and LTB4 The time course of HK formation paralleled that of 5-HETE and LTB4, implying the availability of the 5S-HETE substrate as a limiting factor in biosynthesis rather than expression levels of COX-2. Specific inhibitors of COX-2 and 5-LOX decreased formation of HKD2 and HKE2 Platelets did not form HKs from exogenous 5S-HETE, implying that COX-1 is not involved. HKs are early products during an inflammatory event and require cells that express 5-LOX and COX-2 for their biosynthesis.-Giménez-Bastida, J. A., Shibata, T., Uchida, K., Schneider, C. Roles of 5-lipoxygenase and cyclooxygenase-2 in the biosynthesis of hemiketals E2 and D2 by activated human leukocytes.
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Affiliation(s)
- Juan A Giménez-Bastida
- Department of Pharmacology, Vanderbilt University Medical School, Nashville, Tennessee, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical School, Nashville, Tennessee, USA
| | - Takahiro Shibata
- Division of Biofunctional Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan; and
| | - Koji Uchida
- Division of Biofunctional Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan; and.,Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Claus Schneider
- Department of Pharmacology, Vanderbilt University Medical School, Nashville, Tennessee, USA; .,Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical School, Nashville, Tennessee, USA
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11
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The Intracellular Localisation and Phosphorylation Profile of the Human 5-Lipoxygenase Δ13 Isoform Differs from That of Its Full Length Counterpart. PLoS One 2015; 10:e0132607. [PMID: 26173130 PMCID: PMC4501781 DOI: 10.1371/journal.pone.0132607] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/16/2015] [Indexed: 01/31/2023] Open
Abstract
5-Lipoxygenase (5-LO) catalyzes leukotriene (LT) biosynthesis by a mechanism that involves interactions with 5-lipoxygenase activating protein (FLAP) and coactosin-like protein (CLP). 5-LO splice variants were recently identified in human myeloid and lymphoid cells, including the catalytically inactive ∆13 isoform (5-LO∆13) whose transcript lacks exon 13. 5-LO∆13 inhibits 5-LO product biosynthesis when co-expressed with active full length 5-LO (5-LO1). The objective of this study was to investigate potential mechanisms by which 5-LO∆13 interferes with 5-LO product biosynthesis in transfected HEK293 cells. When co-expressed with 5-LO1, 5-LO∆13 inhibited LT but not 5-hydroxyeicosatetraenoic acid (5-HETE) biosynthesis. This inhibition was independent of 5-LO∆13—FLAP interactions since it occurred in cells expressing FLAP or not. In cell-free assays CLP enhances 5-LO activity through interactions with tryptophan-102 of 5-LO. In the current study, the requirement for W102 was extended to whole cells, as cells expressing the 5-LO1-W102A mutant produced little 5-LO products. W102A mutants of 5-LO∆13 inhibited 5-LO product biosynthesis as effectively as 5-LO∆13 suggesting that inhibition is independent of interactions with CLP. Confocal microscopy showed that 5-LO1 was primarily in the nucleoplasm whereas W102A mutants showed a diffuse cellular expression. Despite the retention of known nuclear localisation sequences, 5-LO∆13 was cytosolic and concentrated in ER-rich perinuclear regions where its effect on LT biosynthesis may occur. W102A mutants of 5-LO∆13 showed the same pattern. Consistent with subcellular distribution patterns, 5-LO∆13 was hyper-phosphorylated on S523 and S273 compared to 5-LO1. Together, these results reveal a role for W102 in nuclear targeting of 5-LO1 suggesting that interactions with CLP are required for nuclear localization of 5-LO1, and are an initial characterisation of the 5-LO∆13 isoform whose inhibition of LT biosynthesis appears independent of interactions with CLP and FLAP. Better knowledge of the regulation and properties of alternative 5-LO isoforms will contribute to understanding the complex regulation of LT biosynthesis.
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12
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Leslie CC. Cytosolic phospholipase A₂: physiological function and role in disease. J Lipid Res 2015; 56:1386-402. [PMID: 25838312 DOI: 10.1194/jlr.r057588] [Citation(s) in RCA: 269] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Indexed: 02/06/2023] Open
Abstract
The group IV phospholipase A2 (PLA2) family is comprised of six intracellular enzymes (GIVA, -B, -C, -D, -E, and -F) commonly referred to as cytosolic PLA2 (cPLA2)α, -β, -γ, -δ, -ε, and -ζ. They contain a Ser-Asp catalytic dyad and all except cPLA2γ have a C2 domain, but differences in their catalytic activities and subcellular localization suggest unique regulation and function. With the exception of cPLA2α, the focus of this review, little is known about the in vivo function of group IV enzymes. cPLA2α catalyzes the hydrolysis of phospholipids to arachidonic acid and lysophospholipids that are precursors of numerous bioactive lipids. The regulation of cPLA2α is complex, involving transcriptional and posttranslational processes, particularly increases in calcium and phosphorylation. cPLA2α is a highly conserved widely expressed enzyme that promotes lipid mediator production in human and rodent cells from a variety of tissues. The diverse bioactive lipids produced as a result of cPLA2α activation regulate normal physiological processes and disease pathogenesis in many organ systems, as shown using cPLA2α KO mice. However, humans recently identified with cPLA2α deficiency exhibit more pronounced effects on health than observed in mice lacking cPLA2α, indicating that much remains to be learned about this interesting enzyme.
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Affiliation(s)
- Christina C Leslie
- Department of Pediatrics, National Jewish Health, Denver, CO 80206; and Departments of Pathology and Pharmacology, University of Colorado Denver, Aurora, CO 80045
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13
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Jin M, Zhou Q, Lee E, Dan S, Duan HQ, Kong D. AS252424, a PI3Kγ Inhibitor, Downregulates Inflammatory Responsiveness in Mouse Bone Marrow-Derived Mast Cells. Inflammation 2014; 37:1254-60. [DOI: 10.1007/s10753-014-9852-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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14
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The interrelationship between leukotriene B4 and leukotriene-A4-hydrolase in collagen/adjuvant-induced arthritis in rats. BIOMED RESEARCH INTERNATIONAL 2014; 2014:730421. [PMID: 24701582 PMCID: PMC3950596 DOI: 10.1155/2014/730421] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 12/29/2022]
Abstract
This study aimed to check the involvement of lipid mediator leukotriene (LT) B4 and the activity of LTA4 hydrolase (LTA4H) in the development of arthritis induced in rats by collagen and adjuvant (CIA). High-performance liquid chromatography (HPLC) and enzyme immunoassay (EIA) were used for measurements of LTB4 and LTA4H in plasma, synovial fluid (SF), soluble (SO), and solubilized membrane-bound fraction (MB) from synovial tissue (ST) and peripheral blood mononuclear cells (PBMCs) of CIA-arthritic and CIA-resistant. EIA process is simple, clean, and rapid and offered advantages over HPLC, showing that in SF and MB-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-resistant, LTB4 and LTA4H were altered in parallel and were positively related. In the plasma and SO-ST and SO-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-arthritic, this pattern was not found. The primordial role played by LTA4H in the biosynthesis of LTB4 was confirmed together with the existence of alternative steps that regulate LTB4 without participation of LTA4H. The involvement of compartmentalized and coupled changes of LTB4 and LTA4H in the resistance and development of arthritis in CIA model was demonstrated for the first time.
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15
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Turner GW, Grimes HD, Lange BM. Soybean vegetative lipoxygenases are not vacuolar storage proteins. FUNCTIONAL PLANT BIOLOGY : FPB 2011; 38:778-787. [PMID: 32480935 DOI: 10.1071/fp11047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 07/23/2011] [Indexed: 06/11/2023]
Abstract
The paraveinal mesophyll (PVM) of soybean is a distinctive uniseriate layer of branched cells situated between the spongy and palisade chlorenchyma of leaves that contains an abundance of putative vegetative storage proteins, Vspα and Vspβ, in its vacuoles. Soybean vegetative lipoxygenases (five isozymes designated as Vlx(A-E)) have been reported to co-localise with Vsp in PVM vacuoles; however, conflicting results regarding the tissue-level and subcellular localisations of specific Vlx isozymes have been reported. We employed immuno-cytochemistry with affinity-purified, isozyme-specific antibodies to reinvestigate the subcellular locations of soybean Vlx isozymes during a sink limitation experiment. VlxB and VlxC were localised to the cytoplasm and nucleoplasm of PVM cells, whereas VlxD was present in the cytoplasm and nucleoplasm of mesophyll chlorenchyma (MC) cells. Label was not associated with storage vacuoles or any evident protein bodies, so our results cast doubt on the hypothesis that Vlx isozymes function as vegetative storage proteins.
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Affiliation(s)
- Glenn W Turner
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - Howard D Grimes
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-7520, USA
| | - B Markus Lange
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
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16
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Haeggström JZ, Funk CD. Lipoxygenase and leukotriene pathways: biochemistry, biology, and roles in disease. Chem Rev 2011; 111:5866-98. [PMID: 21936577 DOI: 10.1021/cr200246d] [Citation(s) in RCA: 609] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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17
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Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
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18
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Jiang Z, Yin X, Jiang Q. Natural forms of vitamin E and 13'-carboxychromanol, a long-chain vitamin E metabolite, inhibit leukotriene generation from stimulated neutrophils by blocking calcium influx and suppressing 5-lipoxygenase activity, respectively. THE JOURNAL OF IMMUNOLOGY 2010; 186:1173-9. [PMID: 21169551 DOI: 10.4049/jimmunol.1002342] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Leukotrienes generated by 5-lipoxygenase (5-LOX)-catalyzed reaction are key regulators of inflammation. In ionophore-stimulated (A23187; 1-2.5 μM) human blood neutrophils or differentiated HL-60 cells, vitamin E forms differentially inhibited leukotriene B(4) (LTB(4)) with an IC(50) of 5-20 μM for γ-tocopherol, δ-tocopherol (δT), and γ-tocotrienol, but a much higher IC(50) for α-tocopherol. 13'-Carboxychromanol, a long-chain metabolite of δT, suppressed neutrophil- and HL-60 cell-generated LTB(4) with an IC(50) of 4-7 μM and potently inhibited human recombinant 5-LOX activity with an IC(50) of 0.5-1 μM. In contrast, vitamin E forms had no effect on human 5-LOX activity but impaired ionophore-induced intracellular calcium increase and calcium influx as well as the subsequent signaling including ERK1/2 phosphorylation and 5-LOX translocation from cytosol to the nucleus, a key event for 5-LOX activation. Further investigation showed that δT suppressed cytosolic Ca(2+) increase and/or LTB(4) formation triggered by ionophores, sphingosine 1-phosphate, and lysophosphatidic acid but not by fMLP or thapsigargin, whereas 13'-carboxychromanol decreased cellular production of LTB(4) regardless of different stimuli, consistent with its strong inhibition of the 5-LOX activity. These observations suggest that δT does not likely affect fMLP receptor-mediated signaling or store depletion-induced calcium entry. Instead, we found that δT prevented ionophore-caused cytoplasmic membrane disruption, which may account for its blocking of calcium influx. These activities by vitamin E forms and long-chain carboxychromanol provide potential molecular bases for the differential anti-inflammatory effects of vitamin E forms in vivo.
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Affiliation(s)
- Ziying Jiang
- Department of Foods and Nutrition, Interdepartmental Nutrition Program, Purdue University, West Lafayette, IN 47907, USA
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19
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Rådmark O, Samuelsson B. Regulation of the activity of 5-lipoxygenase, a key enzyme in leukotriene biosynthesis. Biochem Biophys Res Commun 2010; 396:105-10. [PMID: 20494120 DOI: 10.1016/j.bbrc.2010.02.173] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 02/28/2010] [Indexed: 01/22/2023]
Abstract
5-Lipoxygenase (5LO) catalyzes two steps in the biosynthesis of leukotrienes (LTs), lipid mediators of inflammation derived from arachidonic acid. LTs function in normal host defense, and have pathophysiological roles in chronic inflammatory diseases as asthma and atherosclerosis. Also, possible effects of 5LO products in relation to tumorigenesis have been described. Thus, insight regarding the biochemistry of 5LO is relevant for better understanding of normal physiology, and for development of therapy.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, 17177 Stockholm, Sweden.
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20
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Coffey M, Phare S, Peters-Golden M. INDUCTION OF INDUCIBLE NITRIC OXIDE SYNTHASE BY LIPOPOLYSACCHARIDE/INTERFERON GAMMA AND SEPSIS DOWN-REGULATES 5-LIPOXYGENASE METABOLISM IN MURINE ALVEOLAR MACROPHAGES. Exp Lung Res 2009; 30:615-33. [PMID: 15371096 DOI: 10.1080/01902140490476391] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Pretreatment with lipopolysaccharide (LPS) suppresses rat alveolar macrophage leukotriene synthesis in a nitric oxide (NO)-dependent mechanism. The authors examined the effect of NO on alveolar macrophage leukotriene synthesis following in vitro and in vivo models of sepsis. Treatment of alveolar macrophages from inducible NO synthase (iNOS) wild-type but not knock-out mice with LPS inhibited leukotriene synthesis. iNOS was induced early in alveolar macrophages from cecal ligation and puncture rats and mice compared to sham animals with associated reduced leukotriene synthesis. iNOS knock-out mice were protected from the decrease in alveolar macrophage 5-lipoxygenase metabolism. iNOS regulates alveolar macrophage 5-lipoxygenase metabolism following endotoxin exposure.
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Affiliation(s)
- Michael Coffey
- Division of Pulmonary and Critical Care Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0642, USA.
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21
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Abstract
Leukotrienes (LT) are biologically active lipid mediators known to be involved in allergic inflammation. Leukotrienes have been shown to mediate diverse features of allergic conditions including inflammatory cell chemotaxis/activation and smooth muscle contraction. Cysteinyl leukotrienes (LTC(4), LTD(4) and, LTE(4)) and the dihydroxy leukotriene LTB(4) are generated by a series of enzymes/proteins constituting the LT synthetic pathway or 5-lipoxygenase (5-LO) pathway. Their function is mediated by interacting with multiple receptors. Leukotriene receptor antagonists (LTRA) and LT synthesis inhibitors (LTSI) have shown clinical efficacy in asthma and more recently in allergic rhinitis. Despite growing knowledge of leukotriene biology, the molecular regulation of these inflammatory mediators remains to be fully understood. Genes encoding enzymes of the 5-LO pathway (i.e. ALOX5, LTC4S and LTA4H) and encoding for LT receptors (CYSLTR1/2 and LTB4R1/2) provide excellent candidates for disease susceptibility and severity; however, their role remains unclear. Preliminary data also suggest that 5-LO pathway/receptor gene polymorphism can predict patient responses to LTSI and LTRA; however, the exact mechanisms require elucidation. The aim of this review was to summarize the recent advances in the knowledge of these important mediators, focusing on genetic and pharmacogenetic aspects in the context of allergic phenotypes.
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Affiliation(s)
- N P Duroudier
- Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, UK
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22
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Goodman L, Coles TB, Budsberg S. Leukotriene inhibition in small animal medicine. J Vet Pharmacol Ther 2009; 31:387-98. [PMID: 19000257 DOI: 10.1111/j.1365-2885.2008.00963.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leukotrienes are important mediators of inflammatory and allergic conditions in people and are suspected to play an important role in tumorigenesis and tumor growth of several different tumor types. Based on this, researchers are making great progress in identifying novel pharmacologic targets for several human diseases. Leukotriene inhibition has resulted in therapeutic benefit in clinical trials involving people with osteoarthritis, allergic asthma, and atopic dermatitis. Despite this progress and the possibility that leukotriene inhibition may also play an important therapeutic role in veterinary patients, parallel advances have not yet been made in veterinary medicine. This article summarizes leukotriene function and synthesis. It also reviews the published literature regarding potential therapeutic applications of leukotriene inhibition in both human and veterinary medicine, focusing primarily on osteoarthritis, NSAID induced gastrointestinal mucosal damage, allergic asthma, atopic dermatitis, and cancer.
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Affiliation(s)
- L Goodman
- Small Animal Medicine and Surgery, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA.
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Mahshid Y, Lisy MR, Wang X, Spanbroek R, Flygare J, Christensson B, Björkholm M, Sander B, Habenicht AJR, Claesson HE. High expression of 5-lipoxygenase in normal and malignant mantle zone B lymphocytes. BMC Immunol 2009; 10:2. [PMID: 19134178 PMCID: PMC2631017 DOI: 10.1186/1471-2172-10-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 01/09/2009] [Indexed: 08/08/2023] Open
Abstract
Background Human B lymphocytes can produce leukotriene B4 but the biological function of the 5-lipoxygenase (5-LO) pathway in B cells is unclear. In order to better understand and define the role of 5-LO in B cells, we investigated the expression of 5-LO mRNA and protein in subsets of B cells from human tonsils and different types of B cell lymphoma. Results Based on RT-PCR and western blot/immunohistochemical staining, with a polyclonal antibody raised against 5-LO, high expression of 5-LO was found in mantle zone B cells from tonsils. By contrast, only a weak expression of 5-LO was detected in germinal centre cells and no expression in plasma cells from tonsils. This pattern of 5-LO expression was preserved in malignant lymphoma with high expression in mantle B cell lymphoma (MCL) and weak or no expression in follicular lymphoma. Primary leukemized MCL, so called B-prolymphocytic leukaemia cells, and MCL cell lines also expressed 5-LO and readily produced LTB4 after activation. Conclusion The present report demonstrates the expression of 5-LO mainly in normal and malignant mantle zone B cells while the expression is low or absent in germinal centre B cells and plasma cells, indicating a role of the 5-LO pathway in B cells before the cells finally differentiate to plasma cells.
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Affiliation(s)
- Yilmaz Mahshid
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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24
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Flamand N, Luo M, Peters-Golden M, Brock TG. Phosphorylation of serine 271 on 5-lipoxygenase and its role in nuclear export. J Biol Chem 2009; 284:306-313. [PMID: 18978352 PMCID: PMC2610501 DOI: 10.1074/jbc.m805593200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 10/16/2008] [Indexed: 11/06/2022] Open
Abstract
The enzyme 5-lipoxygenase (5-LO) initiates the biosynthesis of leukotrienes, inflammatory mediators involved in immune diseases and defense. The subcellular localization of 5-LO is regulated, with nuclear import commonly leading to increased leukotriene production. We report here that 5-LO is constitutively phosphorylated on Ser-271 in transfected NIH 3T3 cells. This residue is nested in a classical nuclear export sequence, and phosphorylated Ser-271 5-LO was exclusively found in the nucleus by immunofluorescence and by fractionation techniques. Mutation of Ser-271 to Ala allowed nuclear export of 5-LO that was blocked by the specific nuclear export inhibitor leptomycin b, suggesting that phosphorylation of Ser-271 serves to interfere with exportin-1-mediated nuclear export. Consistent with previous reports that purified 5-LO can be phosphorylated on Ser-271 in vitro by MAPK-activated protein kinase 2, the nuclear export of 5-LO was increased by either treatment with the p38 inhibitor SB 203,580 or co-expression of a kinase-deficient p38 MAPK. Nuclear export of 5-LO can also be induced by KN-93, an inhibitor of Ca2+/calmodulin-dependent kinase II, and the effects of SB 203,580 plus KN-93 are additive. Finally, HeLa cells, which lack nuclear 5-LO, also lack constitutive phosphorylation of Ser-271. Taken together, these results indicate that the phosphorylation of Ser-271 serves to inhibit the nuclear export of 5-LO. This action works in concert with nuclear import, which is regulated by phosphorylation on Ser-523, to determine the subcellular distribution of 5-LO, which in turn regulates leukotriene biosynthesis.
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Affiliation(s)
- Nicolas Flamand
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109 and Centre de recherche de l'Hôpital Laval, Universitá Laval, Quábec City, QC G1V 4G5, Canada; Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109 and Centre de recherche de l'Hôpital Laval, Universitá Laval, Quábec City, QC G1V 4G5, Canada.
| | - Ming Luo
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109 and Centre de recherche de l'Hôpital Laval, Universitá Laval, Quábec City, QC G1V 4G5, Canada
| | - Marc Peters-Golden
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109 and Centre de recherche de l'Hôpital Laval, Universitá Laval, Quábec City, QC G1V 4G5, Canada
| | - Thomas G Brock
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109 and Centre de recherche de l'Hôpital Laval, Universitá Laval, Quábec City, QC G1V 4G5, Canada
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25
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Abstract
Leukotrienes (LTs) are signaling molecules derived from arachidonic acid that initiate and amplify innate and adaptive immunity. In turn, how their synthesis is organized on the nuclear envelope of myeloid cells in response to extracellular signals is not understood. We define the supramolecular architecture of LT synthesis by identifying the activation-dependent assembly of novel multiprotein complexes on the outer and inner nuclear membranes of mast cells. These complexes are centered on the integral membrane protein 5-Lipoxygenase-Activating Protein, which we identify as a scaffold protein for 5-Lipoxygenase, the initial enzyme of LT synthesis. We also identify these complexes in mouse neutrophils isolated from inflamed joints. Our studies reveal the macromolecular organization of LT synthesis.
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26
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ERK-mediated regulation of leukotriene biosynthesis by androgens: a molecular basis for gender differences in inflammation and asthma. Proc Natl Acad Sci U S A 2008; 105:19881-6. [PMID: 19064924 DOI: 10.1073/pnas.0809120105] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
5-Lipoxygenase initiates the biosynthesis of leukotrienes, lipid mediators involved in normal host defense and in inflammatory and allergic disorders. Despite an obvious gender bias in leukotriene-related diseases (e.g., asthma), gender aspects have been neglected in studies on leukotrienes and 5-lipoxygenase. Here, we show that leukotriene formation in stimulated whole blood or neutrophils from males is substantially lower compared with females, accompanied by changed 5-lipoxygenase trafficking. This is due to gender-specific differential activation of extracellular signal-regulated kinases (ERKs). The differences are directly related to variant male/female testosterone plus 5alpha-dihydrotestosterone levels, and addition of 5alpha-dihydrotestosterone to female blood or neutrophils reduced the high (female) LT biosynthesis capacity to low (male) levels. In conclusion, regulation of ERKs and leukotriene formation by androgens constitutes a molecular basis for gender differences in the inflammatory response, and in inflammatory diseases such as asthma.
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27
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Sud'ina GF, Pushkareva MA, Shephard P, Klein T. Cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) selectivity of COX inhibitors. Prostaglandins Leukot Essent Fatty Acids 2008; 78:99-108. [PMID: 18280718 DOI: 10.1016/j.plefa.2007.12.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 12/13/2007] [Accepted: 12/28/2007] [Indexed: 01/20/2023]
Abstract
In vitro evaluations of the selectivity of COX inhibitors are based on a great variety of experimental protocols. As a result, data available on cyclooxygenase (COX)-1/COX-2/5- lipoxygenase (LOX) selectivity of COX inhibitors lack consistency. We, therefore, performed a systematic analysis of the COX-1/COX-2/5-LOX selectivity of 14 compounds with selective COX inhibitory activity (Coxibs). The compounds belonged to different structural classes and were analyzed employing the well-recognized whole-blood assay. 5-LOX activity was also tested on isolated human polymorphonuclear leukocytes. Among COX inhibitors, celecoxib and ML-3000 (licofelone) inhibited 5-LOX in human neutrophils at micromolar ranges. Surprisingly, ML-3000 had no effect on 5-LOX product synthesis in whole-blood assay. In addition, we could show that inhibition of COX pathways did not increase the transformation of arachidonic acid by the 5-LOX pathway.
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Affiliation(s)
- G F Sud'ina
- A.N. Belozersky Institute of Physico-Chemical Biology of the Moscow State University, Leninskie Gory, Building A, 199991 Moscow, Russian Federation.
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28
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Fischer L, Hornig M, Pergola C, Meindl N, Franke L, Tanrikulu Y, Dodt G, Schneider G, Steinhilber D, Werz O. The molecular mechanism of the inhibition by licofelone of the biosynthesis of 5-lipoxygenase products. Br J Pharmacol 2007; 152:471-80. [PMID: 17704828 PMCID: PMC2050828 DOI: 10.1038/sj.bjp.0707416] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Licofelone is a dual inhibitor of the cyclooxygenase and 5-lipoxygenase (5-LO) pathway, and has been developed for the treatment of inflammatory diseases. Here, we investigated the molecular mechanisms underlying the inhibition by licofelone of the formation of 5-LO products. EXPERIMENTAL APPROACH The efficacy of licofelone to inhibit the formation of 5-LO products was analysed in human isolated polymorphonuclear leukocytes (PMNL) or transfected HeLa cells, as well as in cell-free assays using respective cell homogenates or purified recombinant 5-LO. Moreover, the effects of licofelone on the subcellular redistribution of 5-LO were studied. KEY RESULTS Licofelone potently blocked synthesis of 5-LO products in Ca(2+)-ionophore-activated PMNL (IC(50)=1.7 microM) but was a weak inhibitor of 5-LO activity in cell-free assays (IC(50)>>10 microM). The structures of licofelone and MK-886, an inhibitor of the 5-LO-activating protein (FLAP), were superimposable. The potencies of both licofelone and MK-886 in ionophore-activated PMNL were impaired upon increasing the concentration of arachidonic acid, or under conditions where 5-LO product formation was evoked by genotoxic, oxidative or hyperosmotic stress. Furthermore, licofelone prevented nuclear redistribution of 5-LO in ionophore-activated PMNL, as had been observed for FLAP inhibitors. Finally, licofelone as well as MK-886 caused only moderate inhibition of the synthesis of 5-LO products in HeLa cells, unless FLAP was co-transfected. CONCLUSIONS AND IMPLICATIONS Our data suggest that the potent inhibition of the biosynthesis of 5-LO products by licofelone requires an intact cellular environment and appears to be due to interference with FLAP.
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Affiliation(s)
- L Fischer
- Institute of Pharmaceutical Chemistry, University of Frankfurt Frankfurt, Germany
| | - M Hornig
- Institute of Pharmaceutical Chemistry, University of Frankfurt Frankfurt, Germany
| | - C Pergola
- Department of Pharmaceutical Analytics, Institute of Pharmacy, Eberhard-Karls University Tuebingen, Auf der Morgenstelle 8 Tuebingen, Germany
| | - N Meindl
- Institute of Pharmaceutical Chemistry, University of Frankfurt Frankfurt, Germany
| | - L Franke
- Institute of Organic Chemistry, University of Frankfurt, Max-von-Laue-Str. 9 Frankfurt, Germany
| | - Y Tanrikulu
- Institute of Organic Chemistry, University of Frankfurt, Max-von-Laue-Str. 9 Frankfurt, Germany
| | - G Dodt
- Interfakultäres Institut für Biochemie, Eberhard-Karls University Tuebingen Tuebingen, Germany
| | - G Schneider
- Institute of Organic Chemistry, University of Frankfurt, Max-von-Laue-Str. 9 Frankfurt, Germany
| | - D Steinhilber
- Institute of Pharmaceutical Chemistry, University of Frankfurt Frankfurt, Germany
| | - O Werz
- Department of Pharmaceutical Analytics, Institute of Pharmacy, Eberhard-Karls University Tuebingen, Auf der Morgenstelle 8 Tuebingen, Germany
- Author for correspondence:
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29
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Abstract
Leukotrienes are metabolites of arachidonic acid derived from the action of 5-LO (5-lipoxygenase). The immediate product of 5-LO is LTA4 (leukotriene A4), which is enzymatically converted into either LTB4 (leukotriene B4) by LTA4 hydrolase or LTC4 (leukotriene C4) by LTC4 synthase. The regulation of leukotriene production occurs at various levels, including expression of 5-LO, translocation of 5-LO to the perinuclear region and phosphorylation to either enhance or inhibit the activity of 5-LO. Several other proteins, including cPLA2α (cytosolic phospholipase A2α) and FLAP (5-LO-activating protein) also assemble at the perinuclear region before production of LTA4. LTC4 synthase is an integral membrane protein that is present at the nuclear envelope; however, LTA4 hydrolase remains cytosolic. Biologically active LTB4 is metabolized by ω-oxidation carried out by specific cytochrome P450s (CYP4F) followed by β-oxidation from the ω-carboxy position and after CoA ester formation. Other specific pathways of leukotriene metabolism include the 12-hydroxydehydrogenase/15-oxo-prostaglandin-13-reductase that forms a series of conjugated diene metabolites that have been observed to be excreted into human urine. Metabolism of LTC4 occurs by sequential peptide cleavage reactions involving a γ-glutamyl transpeptidase that forms LTD4 (leukotriene D4) and a membrane-bound dipeptidase that converts LTD4 into LTE4 (leukotriene E4) before ω-oxidation. These metabolic transformations of the primary leukotrienes are critical for termination of their biological activity, and defects in expression of participating enzymes may be involved in specific genetic disease.
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Affiliation(s)
- Robert C Murphy
- Department of Pharmacology, Mail Stop 8303, University of Colorado at Denver and Health Sciences Center, 12801 E. 17th Avenue, P.O. Box 6511, Aurora, CO 80045-0511, USA
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30
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Chu LS, Fang SH, Zhou Y, Yu GL, Wang ML, Zhang WP, Wei EQ. Minocycline inhibits 5-lipoxygenase activation and brain inflammation after focal cerebral ischemia in rats. Acta Pharmacol Sin 2007; 28:763-72. [PMID: 17506934 DOI: 10.1111/j.1745-7254.2007.00578.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
AIM To determine whether the anti-inflammatory effect of minocycline on postischemic brain injury is mediated by the inhibition of 5-lipoxygenase (5-LOX) expression and enzymatic activation in rats. METHODS Focal cerebral ischemia was induced for 30 min with middle cerebral artery occlusion, followed by reperfusion. The ischemic injuries, endogenous IgG exudation, the accumulation of neutrophils and macrophage/microglia, and 5-LOX mRNA expression were determined 72 h after reperfusion. 5-LOX metabolites (leukotriene B4 and cysteinyl leukotrienes) were measured 3 h after reperfusion. RESULTS Minocycline (22.5 and 45 mg/kg, ip, for 3 d) attenuated ischemic injuries, IgG exudation, and the accumulation of neutrophils and macrophage/microglia 72 h after reperfusion. It also inhibited 5-LOX expression 72 h after reperfusion and the production of leukotrienes 3 h after reperfusion. CONCLUSION Minocycline inhibited postischemic brain inflammation, which might be partly mediated by the inhibition of 5-LOX expression and enzymatic activation.
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Affiliation(s)
- Li-Sheng Chu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
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31
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Rådmark O, Samuelsson B. 5-Lipoxygenase: Regulation and possible involvement in atherosclerosis. Prostaglandins Other Lipid Mediat 2007; 83:162-74. [PMID: 17481551 DOI: 10.1016/j.prostaglandins.2007.01.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This review article focuses on two aspects regarding 5-lipoxygenase. First, mechanisms for activation of the enzyme. Second, the involvement of 5-lipoxygenase and leukotrienes in atherosclerosis.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institute, S-17177 Stockholm, Sweden.
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32
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Abstract
Leukotrienes are lipid messengers involved in autocrine and paracrine cellular signaling. They are synthesized from arachidonic acid by the 5-lipoxygenase pathway. Current models of this enzymatic pathway recognize that a key step in initiating leukotriene synthesis is the calcium-mediated movement of enzymes, including 5-lipoxygenase, to intracellular membranes. However, 5-lipoxygenase can be imported into or exported from the nucleus before calcium activation. As a result, its subcellular localization will affect its ability to be activated by calcium, as well as the membrane to which it binds and its interaction with other enzymes. This commentary focuses on the role of 5-lipoxygenase compartmentation in determining its regulation and, ultimately, leukotriene synthesis.
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Affiliation(s)
- Thomas G Brock
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA.
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33
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Luo M, Flamand N, Brock TG. Metabolism of arachidonic acid to eicosanoids within the nucleus. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:618-25. [PMID: 16574479 DOI: 10.1016/j.bbalip.2006.02.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 02/20/2006] [Accepted: 02/20/2006] [Indexed: 11/18/2022]
Abstract
The eicosanoids are a diverse family of molecules that have powerful effects on cell function. They are best known as intercellular messengers, having autocrine and paracrine effects following their secretion from the cells that synthesize them. Many of the eicosanoids are produced from one polyunsaturated fatty acid, arachidonic acid. The diversity of possible products that can be synthesized from arachidonic acid is due, in part to the variety of enzymes that can act on it. Over the past 15 years, studies have placed many, but not all, of these enzymes at or inside the nucleus. In some cases, the nuclear import or export of arachidonic acid-processing enzymes is highly regulated. Furthermore, nuclear receptors that are activated by specific eicosanoids are known to exist. Taken together, these findings indicate that the enzymatic conversion of arachidonic acid to specific signaling molecules can occur in the nucleus, that it is regulated, and that the synthesized products may act within the nucleus. The objectives of this commentary are to review what is known about the metabolism of arachidonic acid to eicosanoids within the nucleus and to point to important areas for future discovery.
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Affiliation(s)
- Ming Luo
- Department of Internal Medicine, University of Michigan Health System, 6301 MSRB III, Ann Arbor, MI 48109-0642, USA
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34
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Yan Y, Wang B, Zuo YG, Qu T. Inhibitory Effects of Mizolastine on Ultraviolet B–Induced Leukotriene B4 Production and 5-Lipoxygenase Expression in Normal Human Dermal Fibroblasts In Vitro. Photochem Photobiol 2006; 82:665-9. [PMID: 16402861 DOI: 10.1562/2005-08-17-ra-652] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ultraviolet B (UVB) irradiation exerts hazardous effects such as acute photodamage, skin cancer and photoaging. In this study we evaluated the protective effects of a nonsedative histamine H1-receptor antagonist, mizolastine, on UVB-exposed skin dermal fibroblasts. Therefore, primary human skin fibroblasts were incubated with mizolastine or dexamethasone after 100 mJ/cm(2) UVB irradiation. Leukotriene B4 (LTB4) in fibroblast supernatants was detected with enzyme immunoassays, expression of 5-lipoxygenase (5-LOX) messenger RNA (mRNA) in skin fibroblasts was examined by reverse transcriptase-polymerase chain reaction and expression of 5-LOX protein was measured by immune blotting and immunofluorescent staining with rabbit anti-human 5-LOX antibody. It was found that 0.01 mM mizolastine inhibited UVB-induced LTB4 production from skin fibroblasts at 12, 24 and 36 h. Meanwhile, mizolastine down-regulated 5-LOX mRNA expression and inhibited 5-LOX translocation from nucleus to cytoplasm in fibroblasts. On the basis of these findings, we propose that mizolastine might play a protective role in the pathogenesis of UV radiation-induced acute photodamage of the skin.
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Affiliation(s)
- Yan Yan
- Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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35
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Rådmark O, Samuelsson B. Regulation of 5-lipoxygenase enzyme activity. Biochem Biophys Res Commun 2005; 338:102-10. [PMID: 16122704 DOI: 10.1016/j.bbrc.2005.08.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 08/04/2005] [Indexed: 11/27/2022]
Abstract
In this article, regulation of human 5-lipoxygenase enzyme activity is reviewed. First, structural properties and enzyme activities are described. This is followed by the activating factors: Ca2+, membranes, ATP, and lipid hydroperoxide. Also, studies on phosphorylation of 5-lipoxygenase and nuclear localization sequences are reviewed.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-17177 Stockholm, Sweden.
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36
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Luo M, Jones SM, Flamand N, Aronoff DM, Peters-Golden M, Brock TG. Phosphorylation by protein kinase a inhibits nuclear import of 5-lipoxygenase. J Biol Chem 2005; 280:40609-16. [PMID: 16230355 DOI: 10.1074/jbc.m507045200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzyme 5-lipoxygenase initiates the synthesis of leukotrienes from arachidonic acid. Protein kinase A phosphorylates 5-lipoxygenase on Ser(523), and this reduces its activity. We report here that phosphorylation of Ser(523) also shifts the subcellular distribution of 5-lipoxygenase from the nucleus to the cytoplasm. Phosphorylation and redistribution of 5-lipoxygenase could be produced by overexpression of the protein kinase A catalytic subunit alpha, by pharmacological activators of protein kinase A, and by prostaglandin E(2). Mimicking phosphorylation by replacing Ser(523) with glutamic acid caused cytoplasmic localization; replacement of Ser(523) with alanine prevented phosphorylation and redistribution in response to protein kinase A activation. Because Ser(523) is positioned within the nuclear localization sequence-518 of 5-lipoxygenase, the ability of protein kinase A to phosphorylate and alter the localization of green fluorescent protein fused to the nuclear localization sequence-518 peptide was also tested. Site-directed replacement of Ser(523) with glutamic acid within the peptide impaired nuclear accumulation; overexpression of the protein kinase A catalytic subunit alpha and pharmacological activation of protein kinase caused phosphorylation of the fusion protein at Ser(523), and the phosphorylated protein was found chiefly in the cytoplasm. Taken together, these results indicate that phosphorylation of Ser(523) inhibits the nuclear import function of a nuclear localization sequence, resulting in the accumulation of 5-lipoxygenase enzyme in the cytoplasm. As cytoplasmic localization can be associated with reduced leukotriene synthetic capacity, phosphorylation of Ser(523) serves to inhibit leukotriene production by both impairing catalytic activity and by placing the enzyme in a site that is unfavorable for action.
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Affiliation(s)
- Ming Luo
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109, USA
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37
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Pande AH, Moe D, Nemec KN, Qin S, Tan S, Tatulian SA. Modulation of human 5-lipoxygenase activity by membrane lipids. Biochemistry 2005; 43:14653-66. [PMID: 15544336 DOI: 10.1021/bi048775y] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mammalian 5-lipoxygenase (5-LO) catalyzes the conversion of arachidonic acid (AA) to leukotrienes, potent inflammatory mediators. 5-LO is activated by a Ca(2+)-mediated translocation to membranes, and demonstrates the characteristic features of interfacially activated enzymes, yet the mechanism of membrane binding of 5-LO is not well understood. In an attempt to understand the mechanism of lipid-mediated activation of 5-LO, we have studied the effects of a large set of lipids on human recombinant 5-LO activity, as well as mutual structural effects of 5-LO and membranes. In the presence of 0.35 mM phosphatidylcholine (PC) and 0.2 mM Ca(2+), there was substrate inhibition at >100 microM AA. Data analysis at low AA concentrations yielded the following: K(m) approximately 103 microM and k(cat) approximately 56 s(-1). 5-LO activity was supported by PC more than by any other lipid tested except for a cationic lipid, which was more stimulatory than PC. Binding of 5-LO to zwitterionic and acidic membranes was relatively weak; the extent of binding increased 4-8 times in the presence of Ca(2+), whereas binding to cationic membranes was stronger and essentially Ca(2+)-independent. Polarized attenuated total reflection infrared experiments implied that 5-LO binds to membranes at a defined orientation with the symmetry axis of the putative N-terminal beta-barrel tilted approximately 45 degrees from the membrane normal. Furthermore, membrane binding of 5-LO resulted in dehydration of the membrane surface and was paralleled with stabilization of the structures of both 5-LO and the membrane. Our results provide insight into the understanding of the effects of membrane surface properties on 5-LO-membrane interactions and the interfacial activation of 5-LO.
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Affiliation(s)
- Abhay H Pande
- Biomolecular Science Center, University of Central Florida, Orlando, Florida 32826, USA
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39
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Coffey MJ, Jarvis GE, Gibbins JM, Coles B, Barrett NE, Wylie ORE, O'Donnell VB. Platelet 12-lipoxygenase activation via glycoprotein VI: involvement of multiple signaling pathways in agonist control of H(P)ETE synthesis. Circ Res 2004; 94:1598-605. [PMID: 15142951 DOI: 10.1161/01.res.0000132281.78948.65] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lipoxygenases (LOX) contribute to vascular disease and inflammation through generation of bioactive lipids, including 12-hydro(pero)xyeicosatetraenoic acid (12-H(P)ETE). The physiological mechanisms that acutely control LOX product generation in mammalian cells are uncharacterized. Human platelets that contain a 12-LOX isoform (p12-LOX) were used to define pathways that activate H(P)ETE synthesis in the vasculature. Collagen and collagen-related peptide (CRP) (1 to 10 microg/mL) acutely induced platelet 12-H(P)ETE synthesis. This implicated the collagen receptor glycoprotein VI (GPVI), which signals via the immunoreceptor-based activatory motif (ITAM)-containing FcRgamma chain. Conversely, thrombin only activated at high concentrations (> 0.2 U/mL), whereas U46619 and ADP alone were ineffective. Collagen or CRP-stimulated 12-H(P)ETE generation was inhibited by staurosporine, PP2, wortmannin, BAPTA/AM, EGTA, and L-655238, implicating src-tyrosine kinases, PI3-kinase, Ca2+ mobilization, and p12-LOX translocation. In contrast, protein kinase C (PKC) inhibition potentiated 12-H(P)ETE generation. Finally, activation of the immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing platelet endothelial cell adhesion molecule (PECAM-1) inhibited p12-LOX product generation. This study characterizes a receptor-dependent pathway for 12-H(P)ETE synthesis via the collagen receptor GPVI, which is negatively regulated by PECAM-1 and PKC, and demonstrates a novel link between immune receptor signaling and lipid mediator generation in the vasculature.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/biosynthesis
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/blood
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Adenosine Diphosphate/pharmacology
- Amino Acid Motifs
- Arachidonate 12-Lipoxygenase/blood
- Arachidonate 12-Lipoxygenase/metabolism
- Arachidonic Acid/pharmacology
- Blood Platelets/drug effects
- Blood Platelets/enzymology
- Calcimycin/pharmacology
- Calcium Signaling/drug effects
- Carrier Proteins/pharmacology
- Collagen/pharmacology
- Cyclooxygenase 1
- Egtazic Acid/analogs & derivatives
- Egtazic Acid/pharmacology
- Enzyme Activation/drug effects
- Enzyme Inhibitors/pharmacology
- Humans
- Inflammation/immunology
- Isoenzymes/physiology
- Leukotrienes/biosynthesis
- Leukotrienes/blood
- Leukotrienes/metabolism
- Membrane Proteins
- Peptides/pharmacology
- Phosphorylation/drug effects
- Platelet Activation/drug effects
- Platelet Endothelial Cell Adhesion Molecule-1/physiology
- Platelet Membrane Glycoproteins/physiology
- Prostaglandin-Endoperoxide Synthases/physiology
- Protein Kinase C/antagonists & inhibitors
- Protein Kinase C/physiology
- Protein Processing, Post-Translational/drug effects
- Protein Transport/drug effects
- Quinolines/pharmacology
- Receptors, IgG/physiology
- Thrombin/pharmacology
- p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors
- p38 Mitogen-Activated Protein Kinases/physiology
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Affiliation(s)
- Marcus J Coffey
- Department of Medical Biochemistry and Immunology, University of Wales College of Medicine, Heath Park, Cardiff, UK.
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40
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Lindberg A, Robinson NE, Näsman-Glaser B, Jensen-Waern M, Lindgren JA. Assessment of leukotriene B4 production in leukocytes from horses with recurrent airway obstruction. Am J Vet Res 2004; 65:289-95. [PMID: 15027674 DOI: 10.2460/ajvr.2004.65.289] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the ex vivo leukotriene (LT) biosynthesis in peripheral blood neutrophils (PBNs) and inflammatory cells in bronchoalveolar lavage fluid (BALF) obtained from horses affected with recurrent airway obstruction (RAO). ANIMALS 6 RAO-affected and 6 control horses. PROCEDURES Before and 6, 24, and 48 hours after stabling, disease severity was determined subjectively by clinical and mucus scores and measurement of the maximal change in pleural pressure (deltaPpl(max)); PBNs were isolated and BALF samples were examined cytologically. The PBN and BALF cells were activated with a calcium ionophore in the presence of arachidonic acid, and production of LTC4 and LTB4 was measured per 10(6) cells. RESULTS Clinical and mucus scores and deltaPpl(max) increased during stabling in RAO-affected horses, but not in control horses. In neutrophils and BALF cells from both groups, production of LTB4 exceeded that of LTC4. At all times, LTB4 production by PBNs was less in RAO-affected horses than it was in control horses. Before stabling, LTB4 production by cells in BALF was low in RAO-affected horses, but increased considerably after 6 hours of stabling. This increase coincided with the migration of neutrophils into the airways. In control horses, production of LTB4 did not change during stabling. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested increased production of LTB4 in airways of RAO-affected horses, compared with control horses, that may contribute to the infiltration of neutrophils into the lungs and the sustained inflammation associated with RAO.
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Affiliation(s)
- Asa Lindberg
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-171 77 Stockholm, Sweden
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41
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Li Z, Yang G, Khan M, Stone D, Woo SLY, Wang JHC. Inflammatory response of human tendon fibroblasts to cyclic mechanical stretching. Am J Sports Med 2004; 32:435-40. [PMID: 14977670 DOI: 10.1177/0095399703258680] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The cellular and molecular mechanisms for the development of tendinopathy are not clear, but inflammatory mediators produced by tendon fibroblasts in response to repetitive mechanical loading may be an important factor. HYPOTHESES (1) Cyclic stretching of tendon fibroblasts affects the production of leukotriene B(4) and the expression of 5-lipoxygenase; and (2) the production level of leukotriene B(4) is inversely related to that of prostaglandin E(2). STUDY DESIGN Controlled laboratory study. METHODS Human patellar tendon fibroblasts were uniaxially stretched in the presence of indomethacin (25 micro M) or MK-886 (10 micro M). After stretching for 4 hours, followed by 4 hours rest, levels of prostaglandin E(2), leukotriene B(4), and expression of 5-lipoxygenase were measured. RESULTS Stretched tendon fibroblasts increased the levels of leukotriene B(4) but did not appreciably change the expression of 5-lipoxygenase. Indomethacin decreased the cellular production of prostaglandin E(2) but caused increased leukotriene B(4) levels. MK-886 caused decreased production of leukotriene B(4) but increased production of prostaglandin E(2). CONCLUSIONS Cyclic stretching of human tendon fibroblasts increases the production of prostaglandin E(2) and leukotriene B(4). Blocking prostaglandin E(2) production leads to increased leukotriene B(4) levels and vice versa. CLINICAL RELEVANCE The use of nonsteroidal anti-inflammatory drugs for the treatment of tendon inflammation might increase the levels of leukotriene B(4) within the tendon, potentially contributing to the development of tendinopathy.
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Affiliation(s)
- Zhaozhu Li
- Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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42
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Luo M, Jones SM, Peters-Golden M, Brock TG. Nuclear localization of 5-lipoxygenase as a determinant of leukotriene B4 synthetic capacity. Proc Natl Acad Sci U S A 2003; 100:12165-70. [PMID: 14530386 PMCID: PMC218730 DOI: 10.1073/pnas.2133253100] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The enzyme 5-lipoxygenase (5-LO) initiates the synthesis of leukotrienes from arachidonic acid. In resting cells, 5-LO can accumulate in either the cytoplasm or the nucleoplasm and, upon cell stimulation, translocates to membranes to initiate leukotriene synthesis. Here, we used mutants of 5-LO with altered subcellular localization to assess the role that nuclear positioning plays in determining leukotriene B4 (LTB4) synthesis. Mutation of either a nuclear localization sequence or a phosphorylation site reduced LTB4 synthesis by 60%, in parallel with reduced nuclear localization of 5-LO. Mutation of both sites together or mutation of all three nuclear localization sequences on 5-LO inhibited LTB4 synthesis by 90% and abolished nuclear localization. Reduced LTB4 generation in mutants could not be attributed to differences in 5-LO amount, enzymatic activity, or membrane association. Instead, 5-LO within the nucleus acts at a different site, the nuclear envelope, than does cytosolic 5-LO, which acts at cytoplasmic and perinuclear membranes. The significance of this difference was suggested by evidence that exogenously derived arachidonic acid colocalized with activated nuclear 5-LO. These results unequivocally demonstrate that the positioning of 5-LO within the nucleus of resting cells is a powerful determinant of the capacity to generate LTB4 upon subsequent activation.
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Affiliation(s)
- Ming Luo
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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43
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Abstract
The initial steps in the biosynthesis of leukotrienes from arachidonic acid are carried out by the enzyme 5-lipoxygenase (5-LO). In intact cells, the helper protein 5-LO activating protein (FLAP) is necessary for efficient enzyme utilization of endogenous substrate. The last decade has witnessed remarkable progress in our understanding of these two proteins. Here we review the molecular and cellular aspects of the expression, function, and regulation of 5-LO and FLAP.
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Affiliation(s)
- M Peters-Golden
- Department of Internal Medicine, University of Michigan Health System, 1150 W Medical Center Drive, Ann Arbor, MI 48109-0642, USA.
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Brock TG. Down-regulation of 5-lipoxygenase activity and leukotriene production by prolonged exposure to lipopolysaccharide. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 507:101-5. [PMID: 12664571 DOI: 10.1007/978-1-4615-0193-0_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- Thomas G Brock
- Division of Pulmonary and Critical, Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109-0642, USA
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45
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Jones SM, Luo M, Peters-Golden M, Brock TG. Identification of two novel nuclear import sequences on the 5-lipoxygenase protein. J Biol Chem 2003; 278:10257-63. [PMID: 12525477 DOI: 10.1074/jbc.m211021200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nuclear import of 5-lipoxygenase modulates its capacity to produce leukotrienes from arachidonic acid. However, the molecular determinants of its nuclear import are unknown. Recently, we used structural and functional criteria to identify a novel import sequence at Arg(518) on human 5-lipoxygenase (Jones, S. M., Luo, M., Healy, A. M., Peters-Golden, M., and Brock, T. G. (2002) J. Biol. Chem. 277, 38550-38556). However, this analysis also indicated that other import sequences must exist. Here, we identify two additional sites, at Arg(112) and Lys(158), as nuclear import sequences. Both sites were found to be common to 5-lipoxygenases from different species but not found on other lipoxygenases. Both sites also appeared to be a part of structures that were predominantly random loops. Peptide sequences at these sites were sufficient to direct nuclear import of green fluorescent protein. Mutation of basic residues in these sites impaired nuclear import and combinations of mutations at different sites were additive in effect. Mutations in all three sites were required to disable nuclear accumulation of 5-lipoxygenase in all cells. Significantly, mutation in these sites did not inhibit catalytic function. Taken together, these results indicate that nuclear import of 5-lipoxygenase may reflect the combined functional effects of three discrete import sequences. Mutation of individual sites can, by itself, impair nuclear import, which in turn could impact arachidonic acid metabolism.
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Affiliation(s)
- Sandra M Jones
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor 48109-0642, USA
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Jones SM, Luo M, Healy AM, Peters-Golden M, Brock TG. Structural and functional criteria reveal a new nuclear import sequence on the 5-lipoxygenase protein. J Biol Chem 2002; 277:38550-6. [PMID: 12140292 DOI: 10.1074/jbc.m206070200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukotrienes are lipid mediators with important roles in immunity. The enzyme 5-lipoxygenase initiates leukotriene synthesis; nuclear import of 5-lipoxygenase modulates leukotriene synthetic capacity. In this study, we used structural and functional criteria to identify potential nuclear import sequences. Specifically, we sought basic residues that 1) were common to different 5-lipoxygenases but not shared with other lipoxygenases, 2) were found on random coil/loop structures, and 3) could be replaced without eliminating catalytic activity. Application of these criteria to the putative bipartite nuclear import sequence of 5-lipoxygenase revealed that this region formed an alpha-helix rather than a random coil, that the critical residue arginine 651 serves a structural role, and that mutation of this residue eliminated catalytic activity. A previously unrecognized region corresponding to residues 518-530 on human 5-lipoxygenase was found to be unique to 5-lipoxygenase and on a random coil. This region alone was sufficient to drive import of green fluorescent protein to the same degree as complete 5-lipoxygenase. Replacement of basic residues in this region of the complete protein was capable of eliminating nuclear import without abolishing catalytic activity. Surprisingly, two subpopulations of cells expressing 5-lipoxygenase with this mutated region could be discerned: those with strongly impaired import and those with normal import. Taken together, these results show that the previously identified region with a bipartite motif is not a functional import sequence, whereas the newly identified basic region constitutes a true nuclear import sequence. Moreover, we suggest that another sequence that can mediate nuclear import of 5-lipoxygenase remains to be identified.
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Affiliation(s)
- Sandra M Jones
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, Michigan 48109-0642, USA
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Kim YJ, Kim KP, Han SK, Munoz NM, Zhu X, Sano H, Leff AR, Cho W. Group V phospholipase A2 induces leukotriene biosynthesis in human neutrophils through the activation of group IVA phospholipase A2. J Biol Chem 2002; 277:36479-88. [PMID: 12124392 DOI: 10.1074/jbc.m205399200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We reported previously that exogenously added human group V phospholipase A(2) (hVPLA(2)) could elicit leukotriene B(4) (LTB(4)) biosynthesis in human neutrophils (Han, S. K., Kim, K. P., Koduri, R., Bittova, L., Munoz, N. M., Leff, A. R., Wilton, D. C., Gelb, M. H., and Cho, W. (1999) J. Biol. Chem. 274, 11881-11888). To determine the mechanism of the hVPLA(2)-induced LTB(4) biosynthesis in neutrophils, we thoroughly examined the effects of hVPLA(2) and their lipid products on the activity of group IVA cytosolic PLA(2) (cPLA(2)) and LTB(4) biosynthesis under different conditions. As low as 1 nm exogenous hVPLA(2) was able to induce the release of arachidonic acid (AA) and LTB(4). Typically, AA and LTB(4) were released in two phases, which were synchronized with a rise in intracellular calcium concentration ([Ca(2+)](i)) near the perinuclear region and cPLA(2) phosphorylation. A cellular PLA(2) assay showed that hVPLA(2) acted primarily on the outer plasma membrane, liberating fatty acids and lysophosphatidylcholine (lyso-PC), whereas cPLA(2) acted on the perinuclear membrane. Lyso-PC and polyunsaturated fatty acids including AA activated cPLA(2) and 5-lipoxygenase by increasing [Ca(2+)](i) and inducing cPLA(2) phosphorylation, which then led to LTB(4) biosynthesis. The delayed phase was triggered by the binding of secreted LTB(4) to the cell surface LTB(4) receptor, which resulted in a rise in [Ca(2+)](i) and cPLA(2) phosphorylation through the activation of mitogen-activated protein kinase, extracellular signal-regulated kinase 1/2. These results indicate that a main role of exogenous hVPLA(2) in neutrophil activation and LTB(4) biosynthesis is to activate cPLA(2) and 5-lipoxygenase primarily by liberating from the outer plasma membrane lyso-PC that induces [Ca(2+)](i) increase and cPLA(2) phosphorylation and that hVPLA(2)-induced LTB(4) production is augmented by the positive feedback activation of cPLA(2) by LTB(4).
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Affiliation(s)
- Young Jun Kim
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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Lam BK, Austen KF. Leukotriene C4 synthase: a pivotal enzyme in cellular biosynthesis of the cysteinyl leukotrienes. Prostaglandins Other Lipid Mediat 2002; 68-69:511-20. [PMID: 12432940 DOI: 10.1016/s0090-6980(02)00052-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Leukotriene C4 synthase (LTC4S) conjugates LTA4 with glutathione (GSH) to form LTC4, the parent compound of the cysteinyl LTs. LTC4S is an 18 kDa membrane protein and functions as a noncovalent homodimer. The enzyme activity of LTC4S is augmented by Mg2+ and inhibited by Co2+ and the function of 5-lipoxygenase (LO) activating protein (FLAP) inhibitor MK-886. The Km and Vmax values are 3.6 microM and 1.3 micromol/mg/min for LTA4 and 1.6 mM and 2.7 micromol/mg/min for GSH, respectively. The deduced amino acid sequence and the predicted secondary of LTC4S shares significant homology to FLAP, mGST-2 and mGST-3 which are all members of MAPEG protein superfamily. LTC4S and FLAP exhibited identical genomic organization of five exons and four introns. Site-directed mutagenesis suggests that Arg-51 is involved in opening the epoxide ring of LTA4 and Tyr-93 in GSH thiolate anion formation during catalytic conjugation. LTC4S is a TATA-less gene whose transcription assessed in a reporter construct involved both cell-specific and nonspecific regulatory elements. LTC4S-/- mice grow normally, and are attenuated for innate and adaptive immune inflammatory permeability responses.
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Affiliation(s)
- Bing K Lam
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Abstract
In this article, it has been attempted to review data primarily on the activation of human 5-lipoxygenase, in vitro and in the cell. First, structural properties and enzyme activities are described. This is followed by the activating factors: Ca2+, membranes, ATP, and lipid hydroperoxide. Also, studies on phosphorylation of 5-lipoxygenase, interaction with other proteins, and the intracellullar mobility of 5-lipoxygenase, are reviewed.
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Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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Lindberg A, Näsman-Glaser B, Lindgren JA, Robinson NE. Evaluation of leukotriene biosynthetic capacity in lung tissues from horses with recurrent airway obstruction. Am J Vet Res 2002; 63:794-8. [PMID: 12061522 DOI: 10.2460/ajvr.2002.63.794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate leukotriene (LT) biosynthetic capacity in lung tissue from healthy horses and horses with recurrent airway obstruction (RAO). SAMPLE POPULATION Lung parenchyma and airway specimens from 8 RAO-affected and 5 healthy horses. PROCEDURE Horses were stabled for > or = 72 hours. Blood was drawn before euthanasia, after which lung specimens were collected. Tissue strips from small airways and parenchyma were incubated in organ baths with the precursor LTA4 or stimulated with calcium ionophore A23187 or the tripeptide N-formyl-Met-Leu-Phe (fMLP), with or without exogenous arachidonic acid, in the presence of isolated blood neutrophils. RESULTS Stabling induced typical clinical signs of airway obstruction in RAO-affected horses but not control horses. When lung parenchyma or airway specimens from both groups of horses were incubated with calcium ionophore, with or without arachidonic acid, they did not form LT. In contrast, addition of LTA4 to both tissues resulted in conversion to LTB4, although concentrations of LTC4 were negligible in airways and parenchymal strips from healthy and RAO-affected horses. Incubation of airway and parenchymal strips with suspensions of autologous neutrophils did not influence formation of LT stimulated by calcium ionophore or fMLP, with or without exogenous arachidonic acid. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that lung parenchyma and airway tissues themselves are not of substantial importance for LT formation in the lungs, although these tissues possessed some LTA4 hydrolase activity, enabling LTB4 formation. It may be speculated that LTB4 originates primarily from neutrophils and may play a role in the inflammatory events of RAO.
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Affiliation(s)
- Asa Lindberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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