1
|
Shum M, London CM, Briottet M, Sy KA, Baillif V, Philippe R, Zare A, Ghorbani-Dalini S, Remus N, Tarze A, Escabasse V, Epaud R, Dubourdeau M, Urbach V. CF Patients’ Airway Epithelium and Sex Contribute to Biosynthesis Defects of Pro-Resolving Lipids. Front Immunol 2022; 13:915261. [PMID: 35784330 PMCID: PMC9244846 DOI: 10.3389/fimmu.2022.915261] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/13/2022] [Indexed: 01/07/2023] Open
Abstract
Specialized pro-resolving lipid mediators (SPMs) as lipoxins (LX), resolvins (Rv), protectins (PD) and maresins (MaR) promote the resolution of inflammation. We and others previously reported reduced levels of LXA4 in bronchoalveolar lavages from cystic fibrosis (CF) patients. Here, we investigated the role of CF airway epithelium in SPMs biosynthesis, and we evaluated its sex specificity. Human nasal epithelial cells (hNEC) were obtained from women and men with or without CF. Lipids were quantified by mass spectrometry in the culture medium of hNEC grown at air-liquid interface and the expression level and localization of the main enzymes of SPMs biosynthesis were assessed. The 5-HETE, LXA4, LXB4, RvD2, RvD5, PD1 and RvE3 levels were significantly lower in samples derived from CF patients compared with non-CF subjects. Within CF samples, the 12-HETE, 15-HETE, RvD3, RvD4, 17-HODHE and PD1 were significantly lower in samples derived from females. While the mean expression levels of 15-LO, 5-LO and 12-LO do not significantly differ either between CF and non-CF or between female and male samples, the SPMs content correlates with the level of expression of several enzymes involved in SPMs metabolism. In addition, the 5-LO localization significantly differed from cytoplasmic in non-CF to nucleic (or nuclear envelope) in CF hNEC. Our studies provided evidence for lower abilities of airway epithelial cells derived from CF patients and more markedly, females to produce SPMs. These data are consistent with a contribution of CF airway epithelium in the abnormal resolution of inflammation and with worse pulmonary outcomes in women.
Collapse
Affiliation(s)
- Mickael Shum
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | - Charlie M. London
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | - Maelle Briottet
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | - Khadeeja Adam Sy
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | | | - Reginald Philippe
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U1151 – Institut Necker Enfants Malades (INEM), Paris, France
| | - Abdolhossein Zare
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U1151 – Institut Necker Enfants Malades (INEM), Paris, France
| | - Sadegh Ghorbani-Dalini
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U1151 – Institut Necker Enfants Malades (INEM), Paris, France
| | - Natacha Remus
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
- Centre Hospitalier Intercommunal de Créteil (CHIC), Créteil, France
| | - Agathe Tarze
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | - Virginie Escabasse
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
- Centre Hospitalier Intercommunal de Créteil (CHIC), Créteil, France
| | - Ralph Epaud
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
- Centre Hospitalier Intercommunal de Créteil (CHIC), Créteil, France
| | | | - Valerie Urbach
- University Paris Est Créteil, Institut National de la Santé Et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
- Institut National de la Santé Et de la Recherche Médicale (INSERM) U1151 – Institut Necker Enfants Malades (INEM), Paris, France
- *Correspondence: Valerie Urbach,
| |
Collapse
|
2
|
Dufrusine B, Di Francesco A, Oddi S, Scipioni L, Angelucci CB, D'Addario C, Serafini M, Häfner AK, Steinhilber D, Maccarrone M, Dainese E. Iron-Dependent Trafficking of 5-Lipoxygenase and Impact on Human Macrophage Activation. Front Immunol 2019; 10:1347. [PMID: 31316498 PMCID: PMC6610208 DOI: 10.3389/fimmu.2019.01347] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 05/28/2019] [Indexed: 01/21/2023] Open
Abstract
5-lipoxygenase (5-LOX) is a non-heme iron-containing dioxygenase expressed in immune cells that catalyzes the two initial steps in the biosynthesis of leukotrienes. It is well known that 5-LOX activation in innate immunity cells is related to different iron-associated pro-inflammatory disorders, including cancer, neurodegenerative diseases, and atherosclerosis. However, the molecular and cellular mechanism(s) underlying the interplay between iron and 5-LOX activation are largely unexplored. In this study, we investigated whether iron (in the form of Fe3+ and hemin) might modulate 5-LOX influencing its membrane binding, subcellular distribution, and functional activity. We proved by fluorescence resonance energy transfer approach that metal removal from the recombinant human 5-LOX, not only altered the catalytic activity of the enzyme, but also impaired its membrane-binding. To ascertain whether iron can modulate the subcellular distribution of 5-LOX in immune cells, we exposed THP-1 macrophages and human primary macrophages to exogenous iron. Cells exposed to increasing amounts of Fe3+ showed a redistribution (ranging from ~45 to 75%) of the cytosolic 5-LOX to the nuclear fraction. Accordingly, confocal microscopy revealed that acute exposure to extracellular Fe3+, as well as hemin, caused an overt increase in the nuclear fluorescence of 5-LOX, accompanied by a co-localization with the 5-LOX activating protein (FLAP) both in THP-1 macrophages and human macrophages. The functional relevance of iron overloading was demonstrated by a marked induction of the expression of interleukin-6 in iron-treated macrophages. Importantly, pre-treatment of cells with the iron-chelating agent deferoxamine completely abolished the hemin-dependent translocation of 5-LOX to the nuclear fraction, and significantly reverted its effect on interleukin-6 overexpression. These results suggest that exogenous iron modulates the biological activity of 5-LOX in macrophages by increasing its ability to bind to nuclear membranes, further supporting a role for iron in inflammation-based diseases where its homeostasis is altered and suggesting further evidence of risks related to iron overload.
Collapse
Affiliation(s)
- Beatrice Dufrusine
- Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Andrea Di Francesco
- Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Sergio Oddi
- Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy.,European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy
| | - Lucia Scipioni
- European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy
| | | | - Claudio D'Addario
- Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Mauro Serafini
- Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Ann-Kathrin Häfner
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany
| | - Mauro Maccarrone
- European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Enrico Dainese
- Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy.,European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy
| |
Collapse
|
3
|
Schmider AB, Vaught M, Bauer NC, Elliott HL, Godin MD, Ellis GE, Nigrovic PA, Soberman RJ. The organization of leukotriene biosynthesis on the nuclear envelope revealed by single molecule localization microscopy and computational analyses. PLoS One 2019; 14:e0211943. [PMID: 30735559 PMCID: PMC6368329 DOI: 10.1371/journal.pone.0211943] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022] Open
Abstract
The initial steps in the synthesis of leukotrienes are the translocation of 5-lipoxygenase (5-LO) to the nuclear envelope and its subsequent association with its scaffold protein 5-lipoxygenase-activating protein (FLAP). A major gap in our understanding of this process is the knowledge of how the organization of 5-LO and FLAP on the nuclear envelope regulates leukotriene synthesis. We combined single molecule localization microscopy with Clus-DoC cluster analysis, and also a novel unbiased cluster analysis to analyze changes in the relationships between 5-LO and FLAP in response to activation of RBL-2H3 cells to generate leukotriene C4. We identified the time-dependent reorganization of both 5-LO and FLAP into higher-order assemblies or clusters in response to cell activation via the IgE receptor. Clus-DoC analysis identified a subset of these clusters with a high degree of interaction between 5-LO and FLAP that specifically correlates with the time course of LTC4 synthesis, strongly suggesting their role in the initiation of leukotriene biosynthesis.
Collapse
Affiliation(s)
- Angela B. Schmider
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Melissa Vaught
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Nicholas C. Bauer
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Hunter L. Elliott
- Image and Data Analysis Core, Department of Cell Biology, Harvard Medical School, Boston, MA, United States of America
| | - Matthew D. Godin
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Giorgianna E. Ellis
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Peter A. Nigrovic
- Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Roy J. Soberman
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
- * E-mail:
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Lee MJ, Yoshimoto E, Saijo S, Iwakura Y, Lin X, Katz HR, Kanaoka Y, Barrett NA. Phosphoinositide 3-Kinase δ Regulates Dectin-2 Signaling and the Generation of Th2 and Th17 Immunity. THE JOURNAL OF IMMUNOLOGY 2016; 197:278-87. [PMID: 27194783 DOI: 10.4049/jimmunol.1502485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 04/27/2016] [Indexed: 11/19/2022]
Abstract
The C-type lectin receptor Dectin-2 can trigger the leukotriene C4 synthase-dependent generation of cysteinyl leukotrienes and the caspase-associated recruitment domain 9- and NF-κB-dependent generation of cytokines, such as IL-23, IL-6, and TNF-α, to promote Th2 and Th17 immunity, respectively. Dectin-2 activation also elicits the type 2 cytokine IL-33, but the mechanism by which Dectin-2 induces these diverse innate mediators is poorly understood. In this study, we identify a common upstream requirement for PI3Kδ activity for the generation of each Dectin-2-dependent mediator elicited by the house dust mite species, Dermatophagoides farinae, using both pharmacologic inhibition and small interfering RNA knockdown of PI3Kδ in bone marrow-derived dendritic cells. PI3Kδ activity depends on spleen tyrosine kinase (Syk) and regulates the activity of protein kinase Cδ, indicating that PI3Kδ is a proximal Syk-dependent signaling intermediate. Inhibition of PI3Kδ also reduces cysteinyl leukotrienes and cytokines elicited by Dectin-2 cross-linking, confirming the importance of this molecule in Dectin-2 signaling. Using an adoptive transfer model, we demonstrate that inhibition of PI3Kδ profoundly reduces the capacity of bone marrow-derived dendritic cells to sensitize recipient mice for Th2 and Th17 pulmonary inflammation in response to D. farinae Furthermore, administration of a PI3Kδ inhibitor during the sensitization of wild-type mice prevents the generation of D. farinae-induced pulmonary inflammation. These results demonstrate that PI3Kδ regulates Dectin-2 signaling and its dendritic cell function.
Collapse
Affiliation(s)
- Min Jung Lee
- Department of Medicine, Harvard Medical School, Boston, MA 02115; Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA 02115
| | - Eri Yoshimoto
- Department of Medicine, Harvard Medical School, Boston, MA 02115; Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA 02115
| | - Shinobu Saijo
- Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Yoichiro Iwakura
- Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba 278-0022, Japan; and
| | - Xin Lin
- Department of Molecular and Cellular Oncology, University of Texas, MD Anderson Cancer Center, Houston, TX 77030
| | - Howard R Katz
- Department of Medicine, Harvard Medical School, Boston, MA 02115; Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA 02115
| | - Yoshihide Kanaoka
- Department of Medicine, Harvard Medical School, Boston, MA 02115; Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA 02115
| | - Nora A Barrett
- Department of Medicine, Harvard Medical School, Boston, MA 02115; Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA 02115;
| |
Collapse
|
6
|
Chu J, Praticò D. The 5-Lipoxygenase as modulator of Alzheimer's γ-secretase and therapeutic target. Brain Res Bull 2016; 126:207-212. [PMID: 27005438 DOI: 10.1016/j.brainresbull.2016.03.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/18/2016] [Indexed: 10/22/2022]
Abstract
Alzheimer's disease (AD) is an age-related, neurodegenerative disorder characterized by cognitive impairment with memory loss, extracellular amyloid beta (Aβ) peptides aggregation, and intracellular hyper-phosphorylated tau neurofibrillary tangles (NFT) accumulation. Although the 5-lipoxygenase (5LO) protein enzyme is well known as an important modulators of oxidation and inflammation, recent work has highlighted the new hypothesis that this pathway may play a direct role in AD pathogenesis. In this review article, we will discuss how the 5LO via the γ-secretase influences Aβ peptides formation, and other molecular pathologies including neuroinflammation, synaptic integrity, and cognitive functions, and provide an assessment of how targeting this protein could lead to novel therapeutics for AD and other related neurodegenerative disorders.
Collapse
Affiliation(s)
- Jin Chu
- Department of Pharmacology and Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, United States
| | - Domenico Praticò
- Department of Pharmacology and Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, United States.
| |
Collapse
|
7
|
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.
Collapse
|
8
|
Tang K, Cai Y, Joshi S, Tovar E, Tucker SC, Maddipati KR, Crissman JD, Repaskey WT, Honn KV. Convergence of eicosanoid and integrin biology: 12-lipoxygenase seeks a partner. Mol Cancer 2015; 14:111. [PMID: 26037302 PMCID: PMC4453211 DOI: 10.1186/s12943-015-0382-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 05/08/2015] [Indexed: 11/28/2022] Open
Abstract
Background Integrins and enzymes of the eicosanoid pathway are both well-established contributors to cancer. However, this is the first report of the interdependence of the two signaling systems. In a screen for proteins that interacted with, and thereby potentially regulated, the human platelet-type 12-lipoxygenase (12-LOX, ALOX12), we identified the integrin β4 (ITGB4). Methods Using a cultured mammalian cell model, we have demonstrated that ITGB4 stimulation leads to recruitment of 12-LOX from the cytosol to the membrane where it physically interacts with the integrin to become enzymatically active to produce 12(S)-HETE, a known bioactive lipid metabolite that regulates numerous cancer phenotypes. Results The net effect of the interaction was the prevention of cell death in response to starvation. Additionally, regulation of β4-mediated, EGF-stimulated invasion was shown to be dependent on 12-LOX, and downstream Erk signaling in response to ITGB4 activation also required 12-LOX. Conclusions This is the first report of an enzyme of the eicosanoid pathway being recruited to and regulated by activated β4 integrin. Integrin β4 has recently been shown to induce expansion of prostate tumor progenitors and there is a strong correlation between stage/grade of prostate cancer and 12-LOX expression. The 12-LOX enzymatic product, 12(S)-HETE, regulates angiogenesis and cell migration in many cancer types. Therefore, disruption of integrin β4-12LOX interaction could reduce the pro-inflammatory oncogenic activity of 12-LOX. This report on the consequences of 12-LOX and ITGB4 interaction sets a precedent for the linkage of integrin and eicosanoid biology through direct protein-protein association. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0382-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Keqin Tang
- Department of Radiation Oncology, John D. Dingell VA Medical Center, 48201, Detroit, MI, USA. .,Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| | - Yinlong Cai
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| | - Sangeeta Joshi
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA. .,Present address: Roswell Park Cancer Institute, 14263, Buffalo, New York, USA.
| | - Elizabeth Tovar
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA. .,Program in Cancer Biology, Wayne State University School of Medicine, 48202, Detroit, MI, USA. .,Present address: Van Andel Institute, 49503, Grand Rapids, MI, USA.
| | - Stephanie C Tucker
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| | - Krishna Rao Maddipati
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| | - John D Crissman
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| | - William T Repaskey
- Department of Internal Medicine, University of Michigan, 48109, Ann Arbor, MI, USA.
| | - Kenneth V Honn
- Department of Pathology, Bioactive Lipids Research Program, Wayne State University School of Medicine, Karmanos Cancer Institute, 431 Chemistry Building, 48202, Detroit, MI, USA.
| |
Collapse
|
9
|
Moon TC, Befus AD, Kulka M. Mast cell mediators: their differential release and the secretory pathways involved. Front Immunol 2014; 5:569. [PMID: 25452755 PMCID: PMC4231949 DOI: 10.3389/fimmu.2014.00569] [Citation(s) in RCA: 273] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 10/23/2014] [Indexed: 12/14/2022] Open
Abstract
Mast cells (MC) are widely distributed throughout the body and are common at mucosal surfaces, a major host-environment interface. MC are functionally and phenotypically heterogeneous depending on the microenvironment in which they mature. Although MC have been classically viewed as effector cells of IgE-mediated allergic diseases, they are also recognized as important in host defense, innate and acquired immunity, homeostatic responses, and immunoregulation. MC activation can induce release of pre-formed mediators such as histamine from their granules, as well as release of de novo synthesized lipid mediators, cytokines, and chemokines that play diverse roles, not only in allergic reactions but also in numerous physiological and pathophysiological responses. Indeed, MC release their mediators in a discriminating and chronological manner, depending upon the stimuli involved and their signaling cascades (e.g., IgE-mediated or Toll-like receptor-mediated). However, the precise mechanisms underlying differential mediator release in response to these stimuli are poorly known. This review summarizes our knowledge of MC mediators and will focus on what is known about the discriminatory release of these mediators dependent upon diverse stimuli, MC phenotypes, and species of origin, as well as on the intracellular synthesis, storage, and secretory processes involved.
Collapse
Affiliation(s)
- Tae Chul Moon
- Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - A. Dean Befus
- Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Marianna Kulka
- National Institute for Nanotechnology, National Research Council, Edmonton, AB, Canada
| |
Collapse
|
10
|
Ström JO, Strid T, Hammarström S. Disruption of the alox5ap gene ameliorates focal ischemic stroke: possible consequence of impaired leukotriene biosynthesis. BMC Neurosci 2012. [PMID: 23194405 PMCID: PMC3557197 DOI: 10.1186/1471-2202-13-146] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background Leukotrienes are potent inflammatory mediators, which in a number of studies have been found to be associated with ischemic stroke pathology: gene variants affecting leukotriene synthesis, including the FLAP (ALOX5AP) gene, have in human studies shown correlation to stroke incidence, and animal studies have demonstrated protective properties of various leukotriene-disrupting drugs. However, no study has hitherto described a significant effect of a genetic manipulation of the leukotriene system on ischemic stroke. Therefore, we decided to compare the damage from focal cerebral ischemia between wild type and FLAP knockout mice. Damage was evaluated by infarct staining and a functional test after middle cerebral artery occlusion in 20 wild type and 20 knockout male mice. Results Mortality-adjusted median infarct size was 18.4 (3.2-76.7) mm3 in the knockout group, compared to 72.0 (16.7-174.0) mm3 in the wild type group (p < 0.0005). There was also a tendency of improved functional score in the knockout group (p = 0.068). Analysis of bone marrow cells confirmed that knockout animals had lost their ability to form leukotrienes. Conclusions Since the local inflammatory reaction after ischemic stroke is known to contribute to the brain tissue damage, the group difference seen in the current study could be a consequence of a milder inflammatory reaction in the knockout group. Our results add evidence to the notion that leukotrienes are important in ischemic stroke, and that blocked leukotriene production ameliorates cerebral damage.
Collapse
Affiliation(s)
- Jakob O Ström
- Division of Clinical Chemistry, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | | | | |
Collapse
|
11
|
Ferguson AD. Structure-based drug design on membrane protein targets: human integral membrane protein 5-lipoxygenase-activating protein. Methods Mol Biol 2012; 841:267-290. [PMID: 22222457 DOI: 10.1007/978-1-61779-520-6_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Leukotrienes are biologically active lipid metabolites of arachidonic acid that are involved in inflammation and play a significant role in respiratory and cardiovascular disease. The integral nuclear membrane protein 5-lipoxygenase-activating protein (FLAP) is essential for leukotriene biosynthesis in response to cellular activation. The crystal structures of human FLAP with two inhibitors were recently determined. Inhibitors are bound within the lipid-exposed portion of FLAP, and the unexpected location of the inhibitor-binding site suggests a transport mechanism for arachidonic acid and provides functional insights into leukotriene biosynthesis. This chapter describes how this human integral membrane crystal structure was solved by pushing the limits of low-resolution structure determination and refinement, demonstrating how a low-resolution structure can impact biology and chemistry, and discusses future opportunities for structure-based drug design for this therapeutic target.
Collapse
|
12
|
Abstract
Chagas disease is caused by Trypanosoma cruzi, a protozoan parasite. Chagas disease remains a serious health problem in large parts of Mexico and Central and South America, where it is a major cause of morbidity and mortality. This disease is being increasingly recognized in non-endemic regions due to immigration. Heart disease develops in 10-30% of infected individuals. It is increasingly clear that parasite- and host-derived bioactive lipids potently modulate disease progression. Many of the changes that occur during acute and chronic Chagas disease can be accounted for by the effects of arachidonic acid (AA)-derived lipids such as leukotrienes, lipoxins, H(P)ETEs, prostaglandins (PGs) and thromboxane. During the course of infection with T. cruzi, changes in circulating levels of AA metabolites are observed. Antagonism of PG synthesis with cyclooxygenase (COX) inhibitors has both beneficial and adverse effects. Treatment with COX inhibitors during acute infection may result in increased parasite load and mortality. However, treatment instituted during chronic infection may be beneficial with no increase in mortality and substantial improvement with cardiac function. Recently, T. cruzi infection of mice deficient in AA biosynthetic enzymes for various pathways has yielded more insightful data than pharmacological inhibition and has highlighted the potential deleterious effects of inhibitors due to "off-target" actions. Using COX-1 null mice, it was observed that parasite biosynthesis is dependent upon host metabolism, that the majority of TXA(2) liberated during T. cruzi infection is derived from the parasite and that this molecule may act as a quorum sensor to control parasite growth/differentiation. Thus, eicosanoids present during acute infection may act as immunomodulators aiding the transition to, and maintenance of, the chronic stage of the disease. It is also likely that the same mediators that initially function to ensure host survival may later contribute to cardiovascular damage. Collectively, the eicosanoids represent a new series of targets for therapy in Chagas disease with defined potential therapeutic windows in which to apply these agents for greatest effect. A deeper understanding of the mechanism of action of non-steroidal anti-inflammatory drugs may provide clues to the differences between host responses in acute and chronic T. cruzi infection.
Collapse
|
13
|
Boudreau LH, Bertin J, Robichaud PP, Laflamme M, Ouellette RJ, Flamand N, Surette ME. Novel 5‐lipoxygenase isoforms affect the biosynthesis of 5‐lipoxygenase products. FASEB J 2010; 25:1097-105. [DOI: 10.1096/fj.10-173856] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Luc H. Boudreau
- Département de Chimie et Biochimie Université de Moncton Moncton New Brunswick Canada
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec Departement de Medecine et Faculté de Médecine Université Laval Québec Canada
| | - Jonathan Bertin
- Département de Chimie et Biochimie Université de Moncton Moncton New Brunswick Canada
| | - Philippe P. Robichaud
- Département de Chimie et Biochimie Université de Moncton Moncton New Brunswick Canada
| | - Mark Laflamme
- Atlantic Cancer Research Institute Moncton New Brunswick Canada
- Department of Fisheries and Oceans Canada Moncton New Brunswick Canada
| | | | - Nicolas Flamand
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec Departement de Medecine et Faculté de Médecine Université Laval Québec Canada
| | - Marc E. Surette
- Département de Chimie et Biochimie Université de Moncton Moncton New Brunswick Canada
| |
Collapse
|
14
|
Goodman LA, Jarrett CL, Krunkosky TM, Budsberg SC, Northrup NC, Saba CF, LeRoy BE. 5-Lipoxygenase expression in benign and malignant canine prostate tissues*. Vet Comp Oncol 2010; 9:149-57. [DOI: 10.1111/j.1476-5829.2010.00245.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
15
|
Leslie CC, Gangelhoff TA, Gelb MH. Localization and function of cytosolic phospholipase A2alpha at the Golgi. Biochimie 2010; 92:620-6. [PMID: 20226226 DOI: 10.1016/j.biochi.2010.03.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/04/2010] [Indexed: 11/17/2022]
Abstract
Cytosolic phospholipase A(2)alpha (cPLA(2)alpha, Group IVA phospholipase A(2)) is a central mediator of arachidonate release from cellular phospholipids for the biosynthesis of eicosanoids. cPLA(2)alpha translocates to intracellular membranes including the Golgi in response to a rise in intracellular calcium level. The enzyme's calcium-dependent phospholipid-binding C2 domain provides the targeting specificity for cPLA(2)alpha translocation to the Golgi. However, other features of cPLA(2)alpha regulation are incompletely understood such as the role of phosphorylation of serine residues in the catalytic domain and the function of basic residues in the cPLA(2)alpha C2 and catalytic domains that are proposed to interact with anionic phospholipids in the membrane to which cPLA(2)alpha is targeted. Increasing evidence strongly suggests that cPLA(2)alpha plays a role in regulating Golgi structure, tubule formation and intra-Golgi transport. For example, recent data suggests that cPLA(2)alpha regulates the transport of tight junction and adherens junction proteins through the Golgi to cell-cell contacts in confluent endothelial cells. However, there are now examples where data based on knockdown using siRNA or pharmacological inhibition of enzymatic activity of cPLA(2)alpha affects fundamental cellular processes yet these phenotypes are not observed in cells from cPLA(2)alpha deficient mice. These results suggest that in some cases there may be compensation for the lack of cPLA(2)alpha. Thus, there is continued need for studies employing highly specific cPLA(2)alpha antagonists in addition to genetic deletion of cPLA(2)alpha in mice.
Collapse
Affiliation(s)
- Christina C Leslie
- Department of Pediatrics, National Jewish Health, Denver, CO 80206, USA.
| | | | | |
Collapse
|
16
|
|
17
|
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.
Collapse
Affiliation(s)
- N P Duroudier
- Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, UK
| | | | | |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
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.
Collapse
Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institute, S-17177 Stockholm, Sweden.
| | | |
Collapse
|
20
|
Kalsotra A, Zhao J, Anakk S, Dash PK, Strobel HW. Brain trauma leads to enhanced lung inflammation and injury: evidence for role of P4504Fs in resolution. J Cereb Blood Flow Metab 2007; 27:963-74. [PMID: 16985506 DOI: 10.1038/sj.jcbfm.9600396] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Traumatic brain injury is known to cause several secondary effects, which lead to multiple organ dysfunction syndrome. An acute systemic inflammatory response seems to play an integral role in the development of such complications providing the potential for massive secondary injury. We show that a contusion injury to the rat brain causes large migration of inflammatory cells (especially macrophages and neutrophils) in the major airways and alveolar spaces at 24 h post-injury, which is associated with enhanced pulmonary leukotriene B4 (LTB4) production within the lung. However, by 2 weeks after injury, a temporal switch occurs and the resolution of inflammation is underway. We provide evidence that 5-lipoxygenase and Cytochrome P450 4Fs (CYP4Fs), the respective enzymes responsible for LTB4 synthesis and breakdown, play crucial roles in setting the cellular concentration of LTB4. Activation of LTB4 breakdown via induction of CYP4Fs, predominantly in the lung tissue, serves as an endogenous signal to ameliorate further secondary damage. In addition, we show that CYP4Fs are localized primarily in the airways and pulmonary endothelium. Given the fact that adherence to the microvascular endothelium is an initial step in neutrophil diapedesis, the temporally regulated LTB4 clearance in the endothelium presents a novel focus for treatment of pulmonary inflammation after injury.
Collapse
Affiliation(s)
- Auinash Kalsotra
- Department of Biochemistry and Molecular Biology, The Vivian L Smith Center for Neurologic Research, The University of Texas, Houston Medical School, Houston, Texas 77225, USA
| | | | | | | | | |
Collapse
|
21
|
Chang WC, Nelson C, Parekh AB. Ca2+ influx through CRAC channels activates cytosolic phospholipase A2, leukotriene C4secretion, and expression of c‐fos through ERK‐dependent and independent pathways in mast cells. FASEB J 2006; 20:2381-3. [PMID: 17023391 DOI: 10.1096/fj.06-6016fje] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cytosolic phospholipase A2 (cPLA2) is a Ca2+-dependent enzyme that mediates agonist-dependent arachidonic acid release in most cell types. Arachidonic acid can then be metabolized by the 5-lipoxygenase enzyme to generate the proinflammatory signal leukotriene C4 (LTC4). Here we report that Ca2+ entry through store-operated CRAC (Ca2+ release-activated Ca2+) channels activates the extracellular signal-regulated kinases (ERKs), members of the mitogen-activated protein kinase family, within minutes and this is necessary for stimulation of cPLA2. Ca2+ entry activates ERK indirectly, via recruitment of Ca2+-dependent protein kinase C alpha and betaI. Ca2+ influx also promotes translocation of cytosolic 5-lipoxygenase to the nuclear membrane, a key step in the activation of this enzyme. Translocation is dependent on ERK activation. A role for gene activation is shown by the finding that CRAC channel opening results in increased transcription and translation of c-fos. Inhibition of ERK activation failed to prevent c-fos expression. Our results show that CRAC channel activation elicits short-term effects through the co-coordinated regulation of two metabolic pathways (cPLA2 and 5-lipoxygenase), which results in the generation of both intra- and intercellular messengers within minutes, as well as longer term changes involving gene activation. These short-term effects are mediated via ERK, whereas, paradoxically, c-fos expression is not. Ca2+ influx through CRAC channels can therefore activate different signaling pathways at the same time, culminating in a range of temporally diverse responses.
Collapse
Affiliation(s)
- Wei-Chiao Chang
- Department of Physiology, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | | | | |
Collapse
|
22
|
Zhou Y, Wei EQ, Fang SH, Chu LS, Wang ML, Zhang WP, Yu GL, Ye YL, Lin SC, Chen Z. Spatio-temporal properties of 5-lipoxygenase expression and activation in the brain after focal cerebral ischemia in rats. Life Sci 2006; 79:1645-56. [PMID: 16824548 DOI: 10.1016/j.lfs.2006.05.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 05/13/2006] [Accepted: 05/23/2006] [Indexed: 12/29/2022]
Abstract
The role of 5-lipoxygenase (5-LOX) in brain injury after cerebral ischemia has been reported; however, the spatio-temporal properties of 5-LOX expression and the enzymatic activation are unclear. To determine these properties, we observed post-ischemic 5-LOX changes from 3 h to 14 days after reperfusion in rats with transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. We found that the expression of 5-LOX, both mRNA and protein, was increased in the ischemic core 12-24 h after reperfusion, and in the boundary zone adjacent to the ischemic core 7-14 days after reperfusion. The increased 5-LOX was primarily localized in the neurons in the ischemic core at 24 h, but in the proliferated astrocytes in the boundary zone 14 days after reperfusion. As 5-LOX metabolites, the level of cysteinyl-leukotrienes in the ischemic brain was substantially increased 3 h to 24 h, near control at 3 days, and moderately increased again 7 days after reperfusion; whereas the level of LTB(4) was increased mildly 3 h but substantially 7-14 days after reperfusion. Thus, we conclude that 5-LOX expression and the enzymatic activity are increased after focal cerebral ischemia, and spatio-temporally involved in neuron injury in the acute phase and astrocyte proliferation in the late phase.
Collapse
Affiliation(s)
- Yu Zhou
- Department of Pharmacology, School of Medicine, Zhejiang University, People's Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Kalsotra A, Strobel HW. Cytochrome P450 4F subfamily: at the crossroads of eicosanoid and drug metabolism. Pharmacol Ther 2006; 112:589-611. [PMID: 16926051 DOI: 10.1016/j.pharmthera.2006.03.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 03/22/2006] [Indexed: 12/13/2022]
Abstract
The cytochrome P450 4F (CYP4F) subfamily has over the last few years come to be recognized for its dual role in modulating the concentrations of eicosanoids during inflammation as well as in the metabolism of clinically significant drugs. The first CYP4F was identified because it catalyzed the hydroxylation of leukotriene B(4) (LTB(4)) and since then many additional members of this subfamily have been documented for their distinct catalytic roles and functional significance. Recent evidence emerging in relation to the temporal change of CYP4F expression in response to injury and infection supports an important function for these isozymes in curtailing inflammation. Their tissue-dependent expression, isoform-based catalytic competence and unique response to the external stimuli imply a critical role for them to regulate organ-specific functions. From this standpoint variations in relative CYP4F levels in humans may have direct influence on the metabolic outcome through their ability to generate and/or degrade bioactive eicosanoids or therapeutic agents. This review covers the enzymatic characteristics and regulatory properties of human and rodent CYP4F isoforms and their physiological relevance to major pathways in eicosanoid and drug metabolism.
Collapse
Affiliation(s)
- Auinash Kalsotra
- Department of Biochemistry and Molecular Biology, The University of Texas-Houston Medical School, P.O. Box 20708, 6431 Fannin Street Houston, TX 77225, USA
| | | |
Collapse
|
24
|
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.
Collapse
Affiliation(s)
- Thomas G Brock
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA.
| |
Collapse
|
25
|
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.
Collapse
Affiliation(s)
- Ming Luo
- Department of Internal Medicine, University of Michigan Health System, 6301 MSRB III, Ann Arbor, MI 48109-0642, USA
| | | | | |
Collapse
|
26
|
Ge QF, Wei EQ, Zhang WP, Hu X, Huang XJ, Zhang L, Song Y, Ma ZQ, Chen Z, Luo JH. Activation of 5-lipoxygenase after oxygen-glucose deprivation is partly mediated via NMDA receptor in rat cortical neurons. J Neurochem 2006; 97:992-1004. [PMID: 16606359 DOI: 10.1111/j.1471-4159.2006.03828.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
5-Lipoxygenase (5-LOX) is the enzyme metabolizing arachidonic acid to produce pro-inflammatory leukotrienes. We have reported that 5-LOX is translocated to the nuclear envelope after ischemic-like injury in PC12 cells. In the present study, we determined whether 5-LOX is activated (translocation and production of leukotrienes) after oxygen-glucose deprivation (OGD) in primary rat cortical neurons; if so, whether this activation is mediated by NMDA receptor. After OGD, 5-LOX was translocated to the nuclear envelope as detected by immunoblotting, immunostaining and green fluorescent protein-5-LOX transfection. 5-LOX metabolites, cysteinyl-leukotrienes (CysLTs) but not leukotriene B4, in the culture media were increased 0.5-1.5 h after recovery. Similarly, NMDA (100 microm) also induced 5-LOX translocation, and increased the production of CysLTs during 0.5-1 h NMDA exposure. Both OGD and NMDA reduced neuron viability. NMDA receptor antagonist MK-801 inhibited almost all the responses to OGD and NMDA; whereas 5-LOX activating protein inhibitor MK-886 and 5-LOX inhibitor caffeic acid inhibited the reduction of neuron viability and the production of CysLTs, but did not affect 5-LOX translocation. From these results, we conclude that OGD can activate 5-LOX in primary rat cortical neurons, and that this activation may be partly mediated via activating NMDA receptor.
Collapse
Affiliation(s)
- Qiu-Fu Ge
- Department of Pharmacology, Zheijang University School of Medicine, Hangzhou, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Song Y, Wei EQ, Zhang WP, Ge QF, Liu JR, Wang ML, Huang XJ, Hu X, Chen Z. Minocycline protects PC12 cells against NMDA-induced injury via inhibiting 5-lipoxygenase activation. Brain Res 2006; 1085:57-67. [PMID: 16574083 DOI: 10.1016/j.brainres.2006.02.042] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2005] [Revised: 02/02/2006] [Accepted: 02/07/2006] [Indexed: 11/24/2022]
Abstract
Recently, we have reported that minocycline, a semi-synthetic tetracycline with neuroprotective effects, inhibits the in vitro ischemic-like injury and 5-lipoxygenase (5-LOX) activation in PC12 cells. In the present study, we further determined whether minocycline protects PC12 cells from excitotoxicity via inhibiting 5-LOX activation. We used N-methyl-d-aspartate (NMDA, 200 microM) to induce early (exposure for 6 h) and delayed (exposure for 6 h followed by 24 h recovery) injuries. We found that NMDA receptor antagonist ketamine, 5-LOX inhibitor caffeic acid and minocycline concentration dependently attenuated NMDA-induced early and delayed cell injuries (viability reduction and cell death). However, only ketamine (1 microM) inhibited NMDA-evoked elevation of intracellular calcium. In addition, immunohistochemical analysis showed that NMDA induced 5-LOX translocation to the nuclear membrane after 1- to 6-h exposure which was confirmed by Western blotting, indicating that 5-LOX was activated. Ketamine, caffeic acid and minocycline (each at 1 microM) inhibited 5-LOX translocation after early injury. After delayed injury, PC12 cells were shrunk, and 5-LOX was translocated to the nuclei and nuclear membrane; ketamine, caffeic acid and minocycline inhibited both cell shrinking and 5-LOX translocation. As a control, 12-LOX inhibitor baicalein showed a weak effect on cell viability and death, but no effect on 5-LOX translocation. Therefore, we conclude that the protective effect of minocycline on NMDA-induced injury is partly mediated by inhibiting 5-LOX activation.
Collapse
Affiliation(s)
- Ying Song
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310031, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Zhang L, Zhang WP, Hu H, Wang ML, Sheng WW, Yao HT, Ding W, Chen Z, Wei EQ. Expression patterns of 5-lipoxygenase in human brain with traumatic injury and astrocytoma. Neuropathology 2006; 26:99-106. [PMID: 16708542 DOI: 10.1111/j.1440-1789.2006.00658.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
5-Lipoxygenase (5-LOX) is a key enzyme in the metabolism of arachidonic acid to leukotrienes. The levels of leukotrienes increase after brain injury and when tumors are present. It has been reported that 5-LOX is widely expressed in the brain and that 5-LOX inhibition provides neuroprotection. However, there is still no information available for the expression patterns of 5-LOX in human brain following trauma or with astrocytomas. We investigated its expression patterns by immunohistochemistry. We found that 5-LOX is normally expressed in neurons and glial cells. In neurons, it was expressed in two patterns: in the cytosol and nucleus or only in the cytosol. In traumatic brain injury, 5-LOX expression increased in glial cells and neutrophils. Double-labeling immunohistochemistry showed that part of the 5-LOX-positive glial cells were GFAP positive. No 5-LOX expression was found in brain microvessel endothelia, except in the regenerated endothelia of a patient 8 days following brain trauma. Furthermore, 5-LOX expression increased and showed a granular pattern in high-grade (grade III/IV) astrocytoma. These results indicate that 5-LOX has multiple expression patterns, and can be induced by brain injury, which implies that 5-LOX might have pathophysiological roles in the human brain.
Collapse
Affiliation(s)
- Lei Zhang
- Department of Pharmacology, the Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Aleksandrov DA, Zagryagskaya AN, Pushkareva MA, Bachschmid M, Peters-Golden M, Werz O, Steinhilber D, Sud'ina GF. Cholesterol and its anionic derivatives inhibit 5-lipoxygenase activation in polymorphonuclear leukocytes and MonoMac6 cells. FEBS J 2006; 273:548-57. [PMID: 16420478 DOI: 10.1111/j.1742-4658.2005.05087.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
5-Lipoxygenase (5-LO) is the key enzyme in the biosynthesis of leukotrienes (LTs), biological mediators of host defense reactions and of inflammatory diseases. While the role of membrane binding in the regulation of 5-LO activity is well established, the effects of lipids on cellular activity when added to the medium has not been characterized. Here, we show such a novel function of the most abundant sulfated sterol in human blood, cholesterol sulfate (CS), to suppress LT production in human polymorphonuclear leukocytes (PMNL) and Mono Mac6 cells. We synthesized another anionic lipid, cholesterol phosphate, which demonstrated a similar capacity in suppression of LT synthesis in PMNL. Cholesteryl acetate was without effect. Cholesterol increased the effect of CS on 5-LO product synthesis. CS and cholesterol also inhibited arachidonic acid (AA) release from PMNL. Addition of exogenous AA increased the threshold concentration of CS required to inhibit LT synthesis. The effect of cholesterol and its anionic derivatives can arise from remodeling of the cell membrane, which interferes with 5-LO activation. The fact that cellular LT production is regulated by sulfated cholesterol highlights a possible regulatory role of sulfotransferases/sulfatases in 5-LO product synthesis.
Collapse
Affiliation(s)
- Dmitry A Aleksandrov
- A.N. Belozersky Institute of Physicochemical Biology, Moscow State University, Russia
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Jozefowski S, Biedroń R, Bobek M, Marcinkiewicz J. Leukotrienes modulate cytokine release from dendritic cells. Immunology 2006; 116:418-28. [PMID: 16313356 PMCID: PMC1802435 DOI: 10.1111/j.1365-2567.2005.02241.x] [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: 11/28/2022] Open
Abstract
Leukotriene B(4) (LTB(4)) and cysteinyl leukotrienes (CysLTs) are known as potent mediators of inflammation, whereas their role in the regulation of adaptive immunity remains poorly characterized. Dendritic cells (DCs) are specialized antigen-presenting cells, uniquely capable to initiate primary immune responses. We have found that zymosan, but not lipopolysaccharide (LPS) stimulates murine bone marrow-derived dendritic cells (BM-DCs) to produce large amounts of CysLTs and LTB(4) from endogenous substrates. A selective inhibitor of leukotriene synthesis MK886 as well as an antagonist of the high affinity LTB(4) receptor (BLT(1)) U-75302 slightly inhibited zymosan-, but not LPS-stimulated interleukin (IL)-10 release from BM-DCs. In contrast, U-75302 increased zymosan-stimulated release of IL-12 p40 by approximately 23%. Pre-treatment with transforming growth factor-beta1 enhanced both stimulated leukotriene synthesis and the inhibitory effect of U-75302 and MK886 on IL-10 release from DCs. Consistent with the effects of leukotriene antagonists, exogenous LTB(4) enhanced LPS-stimulated IL-10 release by approximately 39% and inhibited IL-12 p40 release by approximately 22%. Both effects were mediated by the BLT(1) receptor. Ligands of the high affinity CysLTs receptor (CysLT(1)), MK-571 and LTD(4) had little or no effect on cytokine release. Agonists of the nuclear LTB(4) receptor peroxisome proliferator-activated receptor-alpha, 8(S)-hydroxyeicosatetraenoic acid and 5,8,11,14-eicosatetraynoic acid, inhibited release of both IL-12 p40 and IL-10. Our results indicate that both autocrine and paracrine leukotrienes may modulate cytokine release from DCs, in a manner that is consistent with previously reported T helper 2-polarizing effects of leukotrienes.
Collapse
Affiliation(s)
- Szczepan Jozefowski
- Department of Immunology, Jagiellonian University School of Medicine, Kraków, Poland.
| | | | | | | |
Collapse
|
31
|
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.
Collapse
Affiliation(s)
- Yan Yan
- Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | | | | | | |
Collapse
|
32
|
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.
Collapse
Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-17177 Stockholm, Sweden.
| | | |
Collapse
|
33
|
Hanaka H, Shimizu T, Izumi T. Stress-induced nuclear export of 5-lipoxygenase. Biochem Biophys Res Commun 2005; 338:111-6. [PMID: 16165096 DOI: 10.1016/j.bbrc.2005.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 08/25/2005] [Accepted: 09/01/2005] [Indexed: 11/30/2022]
Abstract
A key enzyme for leukotriene biosynthesis is 5-lipoxygenase (5-LO), which we found is exported from the nucleus when p38 MAPK is activated. CHO-K1 cells stably express green fluorescent protein-5-lipoxygenase fusion protein (GFP-5LO), which is located predominantly in the nucleus, and is exported by anisomycin, hydrogen peroxide, and sorbitol, with activation of p38 MAPK. SB203580, an inhibitor of p38 MAPK, and Leptomycin B, an inhibitor of the nuclear export, blocked the anisomycin-induced export of GFP-5LO. When HEK293 cells were transformed with plasmids for wild-type GFP-5LO, GFP-5LO-S271A or GFP-5LO-S271E mutants, most wild-type GFP-5LO and GFP-5LO-S271A localized in the nucleus, but GFP-5LO-S271E localized in the cytosol. Thus, phosphorylation at Ser-271 of 5-LO is important for its export. Endogenous 5-LO in RBL cells stimulated with anisomycin was also exported from the nucleus. These results suggest that the nuclear export of 5-LO depends on the stress-induced activation of the p38 MAPK pathway.
Collapse
Affiliation(s)
- Hiromi Hanaka
- Department of Molecular Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | | | | |
Collapse
|
34
|
Hörnig C, Albert D, Fischer L, Hörnig M, Rådmark O, Steinhilber D, Werz O. 1-Oleoyl-2-acetylglycerol stimulates 5-lipoxygenase activity via a putative (phospho)lipid binding site within the N-terminal C2-like domain. J Biol Chem 2005; 280:26913-21. [PMID: 15923196 DOI: 10.1074/jbc.m500068200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
5-Lipoxygenase (5-LO) catalysis is positively regulated by Ca2+ ions and phospholipids that both act via the N-terminal C2-like domain of 5-LO. Previously, we have shown that 1-oleoyl-2-acetylglycerol (OAG) functions as an agonist for human polymorphonuclear leukocytes (PMNL) in stimulating 5-LO product formation. Here we have demonstrated that OAG directly stimulates 5-LO catalysis in vitro. In the absence of Ca2+ (chelated using EDTA), OAG strongly and concentration-dependently stimulated crude 5-LO in 100,000 x g supernatants as well as purified 5-LO enzyme from PMNL. Also, the monoglyceride 1-O-oleyl-rac-glycerol and 1,2-dioctanoyl-sn-glycerol were effective, whereas various phospholipids did not stimulate 5-LO. However, in the presence of Ca2+, OAG caused no stimulation of 5-LO. Also, phospholipids or cellular membranes abolished the effects of OAG. As found previously for Ca2+, OAG renders 5-LO activity resistant against inhibition by glutathione peroxidase activity, and this effect of OAG is reversed by phospholipids. Intriguingly, a 5-LO mutant lacking tryptophan residues (Trp-13, -75, and -102) important for the binding of the 5-LO C2-like domain to phospholipids was not stimulated by OAG. We conclude that OAG directly stimulates 5-LO by acting at a phospholipid binding site located within the C2-like domain.
Collapse
Affiliation(s)
- Christina Hörnig
- Institute of Pharmaceutical Chemistry, ZAFES, University of Frankfurt, D-60439 Frankfurt, Germany
| | | | | | | | | | | | | |
Collapse
|
35
|
Xu JW, Ikeda K, Kobayakawa A, Ikami T, Kayano Y, Mitani T, Yamori Y. Downregulation of Rac1 activation by caffeic acid in aortic smooth muscle cells. Life Sci 2005; 76:2861-72. [PMID: 15808886 DOI: 10.1016/j.lfs.2004.11.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Accepted: 11/18/2004] [Indexed: 10/25/2022]
Abstract
Caffeic acid, a dietary phenol from coffee, fruits and vegetables, is an efficient antioxidant. However, little is known about its anti-oxidative mechanism in the modulation of fundamental cellular processes. In this study, we investigated whether caffeic acid regulates Rac1 GTPase activity, a partner of NADPH oxidase. Our results showed that caffeic acid decrease Rac1 protein level under basal conditions and incubation with angiotensin II (ANG II) in vascular smooth muscle cells. In a Rac-bound-to-PAK pull down assay, caffeic acid clearly inhibited Rac1 activity. We also observed that caffeic acid suppressed the generation of superoxide anion stimulated by ANG II that activates NADPH oxidase. On the other hand, co-incubation with caffei caid and cycloheximide significantly accelerated the Rac1 degradation. In addition, pretreatment with caffeic acid for 24 hours was able to prevent phosphorylation of MLC and HSP27, when cells were challenged with ANG II through the redox sensitive pathway. These results support the hypothesis that caffeic acid reduces Rac1 GTPase protein and activity level, followed by a down-regulation of NADPH oxidase activity.
Collapse
Affiliation(s)
- Jin-Wen Xu
- Frontier Health Science, School of Human Environmental Science, MUKOGAWA Women's University, Nishinomiya, Hyogo, 663-8179, Japan.
| | | | | | | | | | | | | |
Collapse
|
36
|
Pande AH, Qin S, Tatulian SA. Membrane fluidity is a key modulator of membrane binding, insertion, and activity of 5-lipoxygenase. Biophys J 2005; 88:4084-94. [PMID: 15778441 PMCID: PMC1305639 DOI: 10.1529/biophysj.104.056788] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammalian 5-lipoxygenase (5-LO) catalyzes conversion of arachidonic acid to leukotrienes, potent mediators of inflammation and allergy. Upon cell stimulation, 5-LO selectively binds to nuclear membranes and becomes activated, yet the mechanism of recruitment of 5-LO to nuclear membranes and the mode of 5-LO-membrane interactions are poorly understood. Here we show that membrane fluidity is an important determinant of membrane binding strength of 5-LO, penetration into the membrane hydrophobic core, and activity of the enzyme. The membrane binding strength and activity of 5-LO increase with the degree of lipid acyl chain cis-unsaturation and reach a plateau with 1-palmitoyl-2-arachidonolyl-sn-glycero-3-phosphocholine (PAPC). A fraction of tryptophans of 5-LO penetrate into the hydrocarbon region of fluid PAPC membranes, but not into solid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine membranes. Our data lead to a novel concept of membrane binding and activation of 5-LO, suggesting that arachidonic-acid-containing lipids, which are present in nuclear membranes at higher fractions than in other cellular membranes, may facilitate preferential membrane binding and insertion of 5-LO through increased membrane fluidity and may thereby modulate the activity of the enzyme. The data presented in this article and earlier data allow construction of a model for membrane-bound 5-LO, including the angular orientation and membrane insertion of the protein.
Collapse
Affiliation(s)
- Abhay H Pande
- Biomolecular Science Center, University of Central Florida, Orlando, 32826, USA
| | | | | |
Collapse
|
37
|
Wang H, Li J, Follett PL, Zhang Y, Cotanche DA, Jensen FE, Volpe JJ, Rosenberg PA. 12-Lipoxygenase plays a key role in cell death caused by glutathione depletion and arachidonic acid in rat oligodendrocytes. Eur J Neurosci 2004; 20:2049-58. [PMID: 15450084 DOI: 10.1111/j.1460-9568.2004.03650.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxidative injury to premyelinating oligodendrocytes (preOLs) in developing white matter has been implicated in the pathogenesis of periventricular leukomalacia, the lesion underlying most cases of cerebral palsy in premature infants. In this study, we investigated the pathways of OL death induced by intracellular glutathione (GSH) depletion. We found that the lipoxygenase (LOX) inhibitors AA-861 and BMD-122 (N-benzyl-N-hydroxy-5-phenylpentamide; BHPP), but not the cyclooxygenase (COX) inhibitor indomethacin, fully protected the cells from GSH depletion caused by cystine deprivation. Arachidonic acid (AA), the substrate for 12-LOX, potentiated the toxicity of mild cystine deprivation and at higher concentration was itself toxic. This toxicity was also blocked by 12-LOX inhibitors. Consistent with a role for 12-LOX in the cell death pathway, 12-LOX activity increased following cystine deprivation in OLs. Blocking 12-LOX with AA-861 effectively inhibited the accumulation of reactive oxygen species (ROS) induced by cystine deprivation. These data suggest that, in OLs, intracellular GSH depletion leads to activation of 12-LOX, ROS accumulation and cell death. Mature OLs were more resistant than preOLs to cystine deprivation. The difference in sensitivity was not due to a difference in 12-LOX activity but rather appeared to be related to the presence of stronger antioxidant defense mechanisms in mature OLs. These results suggest that 12-LOX activation plays a key role in oxidative stress-induced OL death.
Collapse
Affiliation(s)
- Hong Wang
- Department of Neurology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Song Y, Wei EQ, Zhang WP, Zhang L, Liu JR, Chen Z. Minocycline protects PC12 cells from ischemic-like injury and inhibits 5-lipoxygenase activation. Neuroreport 2004; 15:2181-4. [PMID: 15371729 DOI: 10.1097/00001756-200410050-00007] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Minocycline protects animals against cerebral ischemia by inhibiting inflammation. To determine whether minocycline protects PC12 cells from in vitro ischemic-like injury and affects pro-inflammatory 5-lipoxygenase activation, the cell viability and 5-lipoxygenase translocation to nuclear membrane were observed after oxygen-glucose deprivation (OGD). We found that OGD reduced cell viability, which was attenuated by minocycline and 5-lipoxygenase inhibitor caffeic acid. 5-Lipoxygenase protein was detected in PC12 cells by immunohistochemical and Western blot analyses. OGD induced 5-lipoxygenase translocation to nuclear membranes, which was abolished by minocycline and caffeic acid. Thus, minocycline can protect PC12 cells from in vitro ischemic-like injury, and this effect may be partly related to the inhibition of 5-lipoxygenase activation.
Collapse
Affiliation(s)
- Ying Song
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310031, China
| | | | | | | | | | | |
Collapse
|
39
|
Chang WC, Parekh AB. Close Functional Coupling between Ca2+ Release-activated Ca2+ Channels, Arachidonic Acid Release, and Leukotriene C4 Secretion. J Biol Chem 2004; 279:29994-9. [PMID: 15133023 DOI: 10.1074/jbc.m403969200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In non-excitable cells, one major route for Ca2+ influx is through store-operated Ca2+ channels in the plasma membrane. These channels are activated by the emptying of intracellular Ca2+ stores, and in some cell types, particularly of hemopoietic origin, store-operated influx occurs through Ca2+ release-activated Ca2+ (CRAC) channels. However, little is known about the downstream consequences of CRAC channel activation. Here, we report that Ca2+ entry through CRAC channels stimulates arachidonic acid production, whereas Ca2+ release from the stores is ineffective even though the latter evokes a robust intracellular Ca2+ signal. We find that arachidonic acid released by Ca2+ entering through CRAC channels is used to synthesize the potent paracrine proinflammatory signal leukotriene C4 (LTC4). Both pharmacological inhibitors of CRAC channels and mitochondrial depolarization, which impairs CRAC channel activity, suppress arachidonic acid release and LTC4 secretion. Thus, arachidonic acid release is preferentially stimulated by elevated subplasmalemmal Ca2+ levels due to open CRAC channels, suggesting that the enzyme is located close to the CRAC channels. Our results also identify a novel role for CRAC channels, namely the activation of a downstream signal transduction pathway resulting in the secretion of LTC4. Finally, mitochondria are key determinants of the generation of both intracellular (arachidonic acid) and paracrine (LTC4) signals through their effects on CRAC channel activity.
Collapse
Affiliation(s)
- Wei-Chiao Chang
- Laboratory of Cellular and Molecular Signalling, Department of Physiology, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom
| | | |
Collapse
|
40
|
Tashiro S, Sumi T, Uozumi N, Shimizu T, Nakamura T. B-Myb-Dependent Regulation of c-Myc Expression by Cytosolic Phospholipase A2. J Biol Chem 2004; 279:17715-22. [PMID: 14769798 DOI: 10.1074/jbc.m310561200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytosolic phospholipase A(2) (cPLA(2)) cleaves membrane phospholipids to release arachidonic acid, initiating lipoxygenase and cyclooxygenase pathways. Mice lacking a gene for cPLA(2) suggested important roles of the protein in allergic responses, fertility, and neural cell death. Here we show that cPLA(2) negatively regulates c-Myc expression in a B-Myb-dependent manner. Overexpression of cPLA(2) protein but not a mutant cPLA(2) protein that lacks in vitro binding ability with B-Myb inhibits B-Myb-dependent c-myc gene expression. The inhibition was associated with physical interaction of B-Myb protein with cPLA(2) both in the cytoplasm and the nucleus. Binding site analysis demonstrated that both the N and C termini of cPLA(2) interact with B-Myb. Macrophage colony stimulating factor (MCSF) stimulated cPLA(2) redistribution into the nucleus and also association with B-Myb in human monocytes. Importantly, macrophages from mice with a disrupted cPLA(2) gene demonstrated significantly increased levels of c-Myc protein in the nucleus compared with cells from the wild-type mice, whereas B-Myb levels were similar in the cells from the cPLA(2)(+/+) and cPLA(2)(-/-) mice. Moreover, an introduction of cPLA(2) into cPLA(2)(-/-) mouse macrophages resulted in decreased c-Myc protein levels, and an inhibition of cPLA(2) expression by small interfering RNAs or antisense RNA increased the c-myc transcription in macrophage colony stimulating factor-activated human monocytes. These findings provide new insights into the function of cPLA(2) in B-Myb-dependent gene expression.
Collapse
Affiliation(s)
- Shigeki Tashiro
- Department of Radiology and Cancer Biology, Nagasaki University School of Dentistry, Nagasaki 852-8588, Japan
| | | | | | | | | |
Collapse
|
41
|
Gilchrist M, McCauley SD, Befus AD. Expression, localization, and regulation of NOS in human mast cell lines: effects on leukotriene production. Blood 2004; 104:462-9. [PMID: 15044250 DOI: 10.1182/blood-2003-08-2990] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide (NO) is a potent radical produced by nitric oxide synthase (NOS) and has pleiotrophic activities in health and disease. As mast cells (MCs) play a central role in both homeostasis and pathology, we investigated NOS expression and NO production in human MC populations. Endothelial NOS (eNOS) was ubiquitously expressed in both human MC lines and skin-derived MCs, while neuronal NOS (nNOS) was variably expressed in the MC populations studied. The inducible (iNOS) isoform was not detected in human MCs. Both growth factor-independent (HMC-1) and -dependent (LAD 2) MC lines showed predominant nuclear eNOS protein localization, with weaker cytoplasmic expression. nNOS showed exclusive cytoplasmic localization in HMC-1. Activation with Ca(2+) ionophore (A23187) or IgE-anti-IgE induced eNOS phosphorylation and translocation to the nucleus and nuclear and cytoplasmic NO formation. eNOS colocalizes with the leukotriene (LT)-initiating enzyme 5-lipoxygenase (5-LO) in the MC nucleus. The NO donor, S-nitrosoglutathione (SNOG), inhibited, whereas the NOS inhibitor, N(G)-nitro-l-arginine methyl ester (L-NAME), potentiated LT release in a dose-dependent manner. Thus, human MC lines produce NO in both cytoplasmic and nuclear compartments, and endogenously produced NO can regulate LT production by MCs.
Collapse
|
42
|
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: 106] [Impact Index Per Article: 5.0] [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.
Collapse
Affiliation(s)
- Ming Luo
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | |
Collapse
|
43
|
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.
Collapse
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.
| | | |
Collapse
|
44
|
Brock TG, McNish RW, Mancuso P, Coffey MJ, Peters-Golden M. Prolonged lipopolysaccharide inhibits leukotriene synthesis in peritoneal macrophages: mediation by nitric oxide and prostaglandins. Prostaglandins Other Lipid Mediat 2003; 71:131-45. [PMID: 14518557 DOI: 10.1016/s1098-8823(03)00036-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Resident rat peritoneal macrophages synthesize a variety of prostanoids and leukotrienes from arachidonic acid. Overnight treatment with lipopolysaccharide (LPS) induces the synthesis of cyclooxygenase-2 (COX-2) and an altered prostanoid profile that emphasizes the preferential conversion of arachidonic acid to prostacyclin and prostaglandin E2. In these studies, we report that exposure to LPS also caused a strong suppression of 5-lipoxygenase but not 12-lipoxygenase activity, indicated by the inhibition of synthesis of both leukotriene B4 and 5-hydroxyeicosatetraenoic acid (5-HETE), but not of 12-HETE. Inhibition of 5-lipoxygenase activity by LPS was both time- and dose-dependent. Treatment of macrophages with prostaglandin E2 partially inhibited leukotriene synthesis, and cyclooxygenase inhibitors partially blocked the inhibition of leukotriene generation in LPS-treated cells. In addition to COX-2, nitric oxide synthase (NOS) was also induced by LPS. Treatment of macrophages with an NO donor mimicked the ability of LPS to significantly reduce leukotriene B4 synthesis. Inhibition of NOS activity in LPS-treated cells blunted the suppression of leukotriene synthesis. Inhibition of both inducible NOS and COX completely eliminated leukotriene suppression. Finally, macrophages exposed to prolonged LPS demonstrated impaired killing of Klebsiella pneumoniae and the combination of NOS and COX inhibitors restored killing to the control level. These results indicate that prolonged exposure to LPS severely inhibits leukotriene production via the combined action of COX and NOS products. The shift in mediator profile, to one that minimizes leukotrienes and emphasizes prostacyclin, prostaglandin E2 and NO, provides a signal that reduces leukocyte function, as indicated by impaired killing of Gram-negative bacteria.
Collapse
Affiliation(s)
- Thomas G Brock
- Department of Internal Medicine, University of Michigan, 6301 MSRB III, Ann Arbor, MI 48109-0642, USA.
| | | | | | | | | |
Collapse
|
45
|
Woo CH, Yoo MH, You HJ, Cho SH, Mun YC, Seong CM, Kim JH. Transepithelial migration of neutrophils in response to leukotriene B4 is mediated by a reactive oxygen species-extracellular signal-regulated kinase-linked cascade. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:6273-9. [PMID: 12794160 DOI: 10.4049/jimmunol.170.12.6273] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The epithelial cells that form a barrier lining the lung airway are key regulators of neutrophil trafficking into the airway lumen in a variety of lung inflammatory diseases. Although the lipid mediator leukotriene B(4) (LTB(4)) is known to be a principal chemoattractant for recruiting neutrophils to inflamed sites across the airway epithelium, the precise signaling mechanism involved remains largely unknown. In the present study, therefore, we investigated the signaling pathway through which LTB(4) induces transepithelial migration of neutrophils. We found that LTB(4) induces concentration-dependent transmigration of DMSO-differentiated HL-60 neutrophils and human polymorphonuclear neutrophils across A549 human lung epithelium. This effect was mediated via specific LTB(4) receptors and was inhibited by pretreating the cells with N-acetylcysteine (NAC), an oxygen free radical scavenger, with diphenylene iodonium (DPI), an inhibitor of NADPH oxidase-like flavoproteins, or with PD98059, an extracellular signal-regulated kinase (ERK) inhibitor. Consistent with those findings, LTB(4)-induced ERK phosphorylation was completely blocked by pretreating cells with NAC or DPI. Taken together, our observations suggest LTB(4) signaling to transepithelial migration is mediated via generation of reactive oxygen species, which leads to downstream activation of ERK. The physiological relevance of this signaling pathway was demonstrated in BALB/c mice, in which intratracheal instillation of LTB(4) led to acute recruitment of neutrophils into the airway across the lung epithelium. Notably, the response to LTB(4) was blocked by NAC, DPI, PD98059, or CP105696, a specific LTB(4) receptor antagonist.
Collapse
Affiliation(s)
- Chang-Hoon Woo
- Graduate School of Biotechnology, Korea University, Anam-dong, Seoul, Korea
| | | | | | | | | | | | | |
Collapse
|
46
|
Tedla N, Bandeira-Melo C, Tassinari P, Sloane DE, Samplaski M, Cosman D, Borges L, Weller PF, Arm JP. Activation of human eosinophils through leukocyte immunoglobulin-like receptor 7. Proc Natl Acad Sci U S A 2003; 100:1174-9. [PMID: 12529506 PMCID: PMC298746 DOI: 10.1073/pnas.0337567100] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Eosinophils are implicated prominently in allergic diseases and the host response to parasitic infections. Eosinophils may be activated in vitro by diverse classes of agonists such as immunoglobulins, lipid mediators, and cytokines. The leukocyte Ig-like receptors (LIRs) comprise a family of inhibitory and activating cell-surface receptors. Inhibitory LIRs down-regulate cellular responses through cytoplasmic immunoreceptor tyrosine-based inhibitory motifs. There are limited data on the action of the activating LIRs, which are thought to signal through the Fc receptor gamma chain, which contains an immunoreceptor tyrosine-based activation motif. We now demonstrate the expression of LIR1 (inhibitory), LIR2 (inhibitory), LIR3 (inhibitory), and LIR7 (activating) on eosinophils from 4, 4, 12, and 11, respectively, of 12 healthy donors. Cross-linking of LIR7 with plate-bound antibody elicited the dose- and time-dependent release of eosinophil-derived neurotoxin and leukotriene C(4). Eosinophils activated with antibodies to LIR7 embedded in gel-phase EliCell preparations showed leukotriene C(4) generation at the nuclear envelope and the release of IL-12 but not IL-4 by vesicular transport. Thus, LIR7 is an activating receptor for eosinophils that elicited the release of cytotoxic granule proteins, de novo lipid mediator generation, and cytokine release through vesicular transport.
Collapse
Affiliation(s)
- Nicodemus Tedla
- Division of Rheumatology, Immunology, and Allergy and Partners Asthma Center, Brigham and Women's Hospital, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Imai H, Nakagawa Y. Biological significance of phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) in mammalian cells. Free Radic Biol Med 2003; 34:145-69. [PMID: 12521597 DOI: 10.1016/s0891-5849(02)01197-8] [Citation(s) in RCA: 533] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) are known mediators of intracellular signal cascades. Excessive production of ROS may lead to oxidative stress, loss of cell function, and cell death by apoptosis or necrosis. Lipid hydroperoxides are one type of ROS whose biological function has not yet been clarified. Phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) is a unique antioxidant enzyme that can directly reduce phospholipid hydroperoxide in mammalian cells. This contrasts with most antioxidant enzymes, which cannot reduce intracellular phospholipid hydroperoxides directly. In this review, we focus on the structure and biological functions of PHGPx in mammalian cells. Recently, molecular techniques have allowed overexpression of PHGPx in mammalian cell lines, from which it has become clear that lipid hydroperoxides also have an important function as activators of lipoxygenase and cyclooxygenase, participate in inflammation, and act as signal molecules for apoptotic cell death and receptor-mediated signal transduction at the cellular level.
Collapse
Affiliation(s)
- Hirotaka Imai
- School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo, Japan
| | | |
Collapse
|
48
|
Coffey MJ, Phare SM, Peters-Golden M. Interaction between nitric oxide, reactive oxygen intermediates, and peroxynitrite in the regulation of 5-lipoxygenase metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1584:81-90. [PMID: 12385890 DOI: 10.1016/s1388-1981(02)00286-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have shown that overnight lipopolysaccharide (LPS) suppresses alveolar macrophage (AM) leukotriene (LT) synthesis mediated in part by induction of inducible nitric oxide synthase (iNOS) and NO production. Here we examined the possibility that reactive oxygen intermediates (ROI) generated by LPS pretreatment contribute to the suppression of 5-lipoxygenase (5-LO) metabolism. Pretreatment of AM with xanthine/xanthine oxidase, which generates high concentrations of ROI, resulted in suppression of LT synthetic capacity. Since NO and ROI reactive species are known to react and form peroxynitrite (ONOO(-)), we examined the effect of ONOO(-) on 5-LO metabolism. Exogenous ONOO(-) caused a dose-dependent suppression of recombinant 5-LO cell-free activity. ONOO(-) also suppressed LT synthesis in intact AM, which was reversed by the ONOO(-) scavenger tetrakis(4-benzoic acid)porphyrin. ONOO(-) treatment also resulted in dose-dependent nitrotyrosination and S-nitrosylation of the recombinant 5-LO enzyme. Since the direct 5-LO inhibitor zileuton prevents the LPS-induced suppression of LT synthesis, we examined if 5-LO itself was the source of ROI. Zileuton reduced ROI generation in LPS-treated cells. These studies identify an important role for ROI and ONOO(-) in the suppression of 5-LO metabolism by LPS.
Collapse
Affiliation(s)
- Michael J Coffey
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical Center, 6301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, MI 48109-0642, USA.
| | | | | |
Collapse
|
49
|
Christmas P, Weber BM, McKee M, Brown D, Soberman RJ. Membrane localization and topology of leukotriene C4 synthase. J Biol Chem 2002; 277:28902-8. [PMID: 12023288 DOI: 10.1074/jbc.m203074200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukotriene C(4) (LTC(4)) synthase conjugates LTA(4) with GSH to form LTC(4). Determining the site of LTC(4) synthesis and the topology of LTC(4) synthase may uncover unappreciated intracellular roles for LTC(4), as well as how LTC(4) is transferred to its export carrier, the multidrug resistance protein-1. We have determined the membrane localization of LTC(4) synthase by immunoelectron microscopy. In contrast to the closely related five-lipoxygenase-activating protein, LTC(4) synthase is distributed in the outer nuclear membrane and peripheral endoplasmic reticulum but is excluded from the inner nuclear membrane. We have combined immunofluorescence with differential membrane permeabilization to determine the topology of LTC(4) synthase. The active site of LTC(4) synthase is localized in the lumen of the nuclear envelope and endoplasmic reticulum. These results indicate that the synthesis of LTB(4) and LTC(4) occurs in different subcellular locations and suggests that LTC(4) must be returned to the cytoplasmic side of the membrane for export by multidrug resistance protein-1. The differential localization of two very similar integral membrane proteins suggests that mechanisms other than size-dependent exclusion regulate their passage to the inner nuclear membrane.
Collapse
Affiliation(s)
- Peter Christmas
- Renal Unit and Program in Membrane Biology, Department of Medicine, Harvard Medical School and Massachusetts General Hospital (East), Charlestown, Massachusetts 02129, USA
| | | | | | | | | |
Collapse
|
50
|
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.
Collapse
Affiliation(s)
- Olof Rådmark
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|