1
|
Nakatsutsumi K, Morishita K, Yagi M, Doki S, Watanabe A, Ikegami N, Kobayashi T, Kojima M, Senda A, Yamamoto K, Aiboshi J, Coimbra R, Otomo Y. Vagus nerve stimulation modulates arachidonic acid production in the mesenteric lymph following intestinal ischemia-reperfusion injury. J Trauma Acute Care Surg 2021; 91:700-707. [PMID: 34238858 DOI: 10.1097/ta.0000000000003345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Inflammatory lipid mediators in mesenteric lymph (ML), including arachidonic acid (AA), are considered to play an important role in the pathogenesis of multiple-organ dysfunction after hemorrhagic shock. A previous study suggested that vagus nerve stimulation (VNS) could relieve shock-induced gut injury and abrogate ML toxicity, resulting in the prevention of multiple-organ dysfunction. However, the detailed mechanism of VNS in lymph toxicity remains unclear. The study aimed to investigate the relationship between VNS and inflammatory lipid mediators in ML. METHODS Male Sprague-Dawley rats underwent laparotomy and superior mesenteric artery obstruction (SMAO) for 60 minutes to induce intestinal ischemia followed by reperfusion and observation. The ML duct was cannulated, and ML samples were obtained both before and after SMAO. The distal ileum was removed at the end of the observation period. In one group of animals, VNS was performed from 10 minutes before 10 minutes after SMAO (5 V, 0.5 Hz). Liquid chromatography-electrospray ionization-tandem mass spectrometry analysis of AA was performed for each ML sample. The biological activity of ML was examined using a monocyte nuclear factor κ-light-chain-enhancer of activated B cells activation assay. Western blotting of phospholipase A2 group IIA (PLA2-IIA) was also performed for ML and ileum samples. RESULTS Vagus nerve stimulation relieved the SMAO-induced histological gut injury. The concentration of AA and level of nuclear factor κ-light-chain-enhancer of activated B cells activation in ML increased significantly after SMAO, whereas VNS prevented these responses. Western blotting showed PLA2-IIA expression in the ML and ileum after SMAO; however, the appearance of PLA2-IIA band was remarkably decreased in the samples from VNS-treated animals. CONCLUSION The results suggested that VNS could relieve gut injury induced by SMAO and decrease the production of AA in ML by altering PLA2-IIA expression in the gut and ML.
Collapse
Affiliation(s)
- Keita Nakatsutsumi
- From the Department of Acute Critical Care and Disaster Medicine (K.N., Y.O.), Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University; Department of Acute Critical Care and Disaster Medicine (K.N., K.M., A.S., J.A., Y.O.), Tokyo Medical and Dental University Hospital of Medicine; Department of Biological Sciences (S.D., A.W., N.I., T.K.), Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo; Emergency Medicine and Acute Care Surgery (M.Y.), Matsudo City General Hospital, Chiba; Emergency and Critical Care Center (M.K.), Tokyo Women's Medical University Medical Center East; Department of Comprehensive Pathology (K.Y.), Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; and Department of Surgery (R.C.), Riverside University Health System Medical Center, Loma Linda University School of Medicine, Loma Linda, California
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Archambault AS, Poirier S, Lefebvre JS, Robichaud PP, Larose MC, Turcotte C, Martin C, Provost V, Boudreau LH, McDonald PP, Laviolette M, Surette ME, Flamand N. 20-Hydroxy- and 20-carboxy-leukotriene (LT) B4
downregulate LTB4
-mediated responses of human neutrophils and eosinophils. J Leukoc Biol 2019; 105:1131-1142. [DOI: 10.1002/jlb.ma0718-306r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 12/15/2018] [Indexed: 12/24/2022] Open
Affiliation(s)
- Anne-Sophie Archambault
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Samuel Poirier
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
- Département de chimie et de biochimie; Université de Moncton; Moncton NB E1A 3E9 Canada
| | - Julie-S Lefebvre
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | | | - Marie-Chantal Larose
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Caroline Turcotte
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Cyril Martin
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Véronique Provost
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Luc H. Boudreau
- Département de chimie et de biochimie; Université de Moncton; Moncton NB E1A 3E9 Canada
| | - Patrick P. McDonald
- Centre de recherche du CHUS et Faculté de Médecine; Université de Sherbrooke; Sherbrooke QC J1H 5N4 Canada
| | - Michel Laviolette
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| | - Marc E. Surette
- Département de chimie et de biochimie; Université de Moncton; Moncton NB E1A 3E9 Canada
| | - Nicolas Flamand
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval; Département de médecine; Faculté de médecine; Université Laval; Québec City QC G1V 4G5 Canada
| |
Collapse
|
3
|
Xu X, Jin T. ELMO proteins transduce G protein-coupled receptor signal to control reorganization of actin cytoskeleton in chemotaxis of eukaryotic cells. Small GTPases 2017. [PMID: 28641070 PMCID: PMC6548286 DOI: 10.1080/21541248.2017.1318816] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Chemotaxis, which is chemoattractant-guided directional cell migration, plays major roles in recruitment of neutrophils, the metastasis of cancer cells, and the development of the model organism Dictyostelium discoideum. These cells share remarkable similarities in the signaling pathways by which they control chemotaxis. They all use a G protein-coupled receptor (GPCR)-mediated signal transduction pathway to sense the chemotactic gradient to guide cell migration. Diverse chemokines activate Rac through conserved GPCR signaling pathways. ELMO proteins are an evolutionarily conserved, essential component of the ELMO/Dock complex, which functions as a guanine nucleotide exchange factor (GEF) for small G protein Rac activation. The linkages between the GPCR-initiated gradient sensing compass and the Rac-mediated migrating machinery have long been missing. Here, we summarize recent findings on ELMO proteins that directly interact with G protein and transduce GPCR signaling to control the reorganization of actin-based cytoskeleton through regulating Rac activation during chemotaxis, first in D. discoideum and then in mammalian cancer cells. This represents an evolutionarily conserved signaling shortcut from GPCR to the actin cytoskeleton.
Collapse
Affiliation(s)
- Xuehua Xu
- a Chemotaxis Signal Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
| | - Tian Jin
- a Chemotaxis Signal Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
| |
Collapse
|
4
|
Regulators and Effectors of Arf GTPases in Neutrophils. J Immunol Res 2015; 2015:235170. [PMID: 26609537 PMCID: PMC4644846 DOI: 10.1155/2015/235170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/30/2015] [Indexed: 12/22/2022] Open
Abstract
Polymorphonuclear neutrophils (PMNs) are key innate immune cells that represent the first line of defence against infection. They are the first leukocytes to migrate from the blood to injured or infected sites. This process involves molecular mechanisms that coordinate cell polarization, delivery of receptors, and activation of integrins at the leading edge of migrating PMNs. These phagocytes actively engulf microorganisms or form neutrophil extracellular traps (NETs) to trap and kill pathogens with bactericidal compounds. Association of the NADPH oxidase complex at the phagosomal membrane for production of reactive oxygen species (ROS) and delivery of proteolytic enzymes into the phagosome initiate pathogen killing and removal. G protein-dependent signalling pathways tightly control PMN functions. In this review, we will focus on the small monomeric GTPases of the Arf family and their guanine exchange factors (GEFs) and GTPase activating proteins (GAPs) as components of signalling cascades regulating PMN responses. GEFs and GAPs are multidomain proteins that control cellular events in time and space through interaction with other proteins and lipids inside the cells. The number of Arf GAPs identified in PMNs is expanding, and dissecting their functions will provide important insights into the role of these proteins in PMN physiology.
Collapse
|
5
|
Schumann J, Basiouni S, Gück T, Fuhrmann H. Treating canine atopic dermatitis with unsaturated fatty acids: the role of mast cells and potential mechanisms of action. J Anim Physiol Anim Nutr (Berl) 2014; 98:1013-20. [DOI: 10.1111/jpn.12181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 02/13/2014] [Indexed: 12/12/2022]
Affiliation(s)
- J. Schumann
- Institute of Physiological Chemistry; Faculty of Veterinary Medicine; University of Leipzig; Leipzig Germany
| | - S. Basiouni
- Institute of Physiological Chemistry; Faculty of Veterinary Medicine; University of Leipzig; Leipzig Germany
- Department of Clinical Pathology; Faculty of Veterinary Medicine; Benha University; Moshtohor Toukh Qalioubeya Egypt
| | - T. Gück
- Hills Pet Nutrition; Hamburg Germany
| | - H. Fuhrmann
- Institute of Physiological Chemistry; Faculty of Veterinary Medicine; University of Leipzig; Leipzig Germany
| |
Collapse
|
6
|
The influence of polyunsaturated fatty acids on the phospholipase D isoforms trafficking and activity in mast cells. Int J Mol Sci 2013; 14:9005-17. [PMID: 23698760 PMCID: PMC3676769 DOI: 10.3390/ijms14059005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/15/2013] [Accepted: 04/18/2013] [Indexed: 11/16/2022] Open
Abstract
The impact of polyunsaturated fatty acid (PUFA) supplementation on phospholipase D (PLD) trafficking and activity in mast cells was investigated. The enrichment of mast cells with different PUFA including α-linolenic acid (LNA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LA) or arachidonic acid (AA) revealed a PUFA-mediated modulation of the mastoparan-stimulated PLD trafficking and activity. All PUFA examined, except AA, prevented the migration of the PLD1 to the plasma membrane. For PLD2 no PUFA effects on trafficking could be observed. Moreover, PUFA supplementation resulted in an increase of mastoparan-stimulated total PLD activity, which correlated with the number of double bonds of the supplemented fatty acids. To investigate, which PLD isoform was affected by PUFA, stimulated mast cells were supplemented with DHA or AA in the presence of specific PLD-isoform inhibitors. It was found that both DHA and AA diminished the inhibition of PLD activity in the presence of a PLD1 inhibitor. By contrast, only AA diminished the inhibition of PLD activity in the presence of a PLD2 inhibitor. Thus, PUFA modulate the trafficking and activity of PLD isoforms in mast cells differently. This may, in part, account for the immunomodulatory effect of unsaturated fatty acids and contributes to our understanding of the modulation of mast cell activity by PUFA.
Collapse
|
7
|
Hypertonic saline inhibits arachidonic acid priming of the human neutrophil oxidase. J Surg Res 2011; 174:24-8. [PMID: 21816415 DOI: 10.1016/j.jss.2011.06.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 05/19/2011] [Accepted: 06/10/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND Arachidonic acid (AA, and its leukotriene derivatives, e.g., LTB(4)) is an inflammatory mediator in post-shock mesenteric lymph that appears to act as an agonist on G-protein coupled receptors (GPCRs). These mediators prime neutrophils (PMNs) for an increased production of superoxide, implicated in the development of acute lung injury (ALI). Hypertonic saline (HTS) has also been shown to have immunomodulatory effects such as attenuation of PMN priming by precluding appropriate clathrin-mediated endocytosis of activated GPCRs, thereby potentially attenuating ALI. We hypothesize that HTS inhibits priming of the PMN oxidase by these lipid mediators. METHODS After PMNs were isolated from healthy donors, incubation was done in either isotonic buffer (control) or HTS (180 mmol/L) for 5 min at 37°C. The PMNs were then primed for 10 min with AA [5 μM] or 5 min with LTB(4) [1 μM] and the oxidase was activated with 200 ng/mL of phorbol 12-myristate 13-acetate (PMA), a non-GPCR activator, and superoxide anion generation was measured via reduction of cytochrome c. RESULTS Both AA [5 μM] and LTB(4) [1 μM] significantly primed the PMA activated respiratory burst (P < 0.05, ANOVA, Newman-Keuls, n = 4). HTS inhibited both AA and LTB(4) priming of the respiratory burst. CONCLUSIONS These data indicate that HTS reduces the cytotoxicity of PMNs stimulated by these lipid mediators in vitro and further support the immunomodulatory effects of HTS.
Collapse
|
8
|
Gemeinhardt A, Alfalah M, Gück T, Naim HY, Fuhrmann H. The influence of linoleic and linolenic acid on the activity and intracellular localisation of phospholipase D in COS-1 cells. Biol Chem 2009; 390:253-8. [DOI: 10.1515/bc.2009.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractPhospholipase D (PLD) is a receptor-regulated signalling enzyme involved in biological functions, such as exocytosis, phagocytosis, actin dynamics, membrane trafficking, and is considered to be essential for stimulated degranulation of cells. The purpose of our investigation was to examine how the fatty acid pattern of cellular membranes influences the activities and cellular distribution of the PLD1 and PLD2 isoforms. Expression of GFP-tagged PLD1 and PLD2 in COS-1 cells that were stimulated with mastoparan after cultivation in 20 μmol linoleic (C18:2n6) or linolenic (C18:3n3) acid for 4 d demonstrated that PLD1 dramatically alters its cellular distribution and is redistributed from intracellular vesicles to the cell surface. PLD2, on the other hand, maintains its localisation at the plasma membrane. The activity of PLD, which corresponds to PLD1 and PLD2, significantly increased two- to three-fold in the presence of the fatty acids. We conclude that linoleic acid and linolenic acid supplementation affect the intracellular trafficking of the PLD1 isoform and the activity of PLD most likely due to alterations in the membrane lipid environment conferred by the fatty acids.
Collapse
|
9
|
Abstract
Extracellular adenosine is produced in a coordinated manner from cells following cellular challenge or tissue injury. Once produced, it serves as an autocrine- and paracrine-signaling molecule through its interactions with seven-membrane-spanning G-protein-coupled adenosine receptors. These signaling pathways have widespread physiological and pathophysiological functions. Immune cells express adenosine receptors and respond to adenosine or adenosine agonists in diverse manners. Extensive in vitro and in vivo studies have identified potent anti-inflammatory functions for all of the adenosine receptors on many different inflammatory cells and in various inflammatory disease processes. In addition, specific proinflammatory functions have also been ascribed to adenosine receptor activation. The potent effects of adenosine signaling on the regulation of inflammation suggest that targeting specific adenosine receptor activation or inactivation using selective agonists and antagonists could have important therapeutic implications in numerous diseases. This review is designed to summarize the current status of adenosine receptor signaling in various inflammatory cells and in models of inflammation, with an emphasis on the advancement of adenosine-based therapeutics to treat inflammatory disorders.
Collapse
Affiliation(s)
- Michael R Blackburn
- Department of Biochemistry and Molecular Biology, The University of Texas-Houston Medical School, Houston, TX 77030, USA.
| | | | | | | |
Collapse
|
10
|
Jordan JR, Moore EE, Sarin EL, Damle SS, Kashuk SB, Silliman CC, Banerjee A. Arachidonic acid in postshock mesenteric lymph induces pulmonary synthesis of leukotriene B4. J Appl Physiol (1985) 2008; 104:1161-6. [PMID: 18276905 DOI: 10.1152/japplphysiol.00022.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mesenteric lymph is the mechanistic link between splanchnic hypoperfusion and acute lung injury (ALI), but the culprit mediator(s) remains elusive. Previous work has shown that administration of a phospholipase A(2) (PLA(2)) inhibitor attenuated postshock ALI and also identified a non-ionic lipid within the postshock mesenteric lymph (PSML) responsible for polymorphonuclear neutrophil (PMN) priming. Consequently, we hypothesized that gut-derived leukotriene B(4) (LTB(4)) is a key mediator in the pathogenesis of ALI. Trauma/hemorrhagic shock (T/HS) was induced in male Sprague-Dawley rats and the mesenteric duct cannulated for lymph collection/diversion. PSML, arachidonic acid (AA), and a LTB(4) receptor antagonist were added to PMNs in vitro. LC/MS/MS was employed to identify bioactive lipids in PSML and the lungs. T/HS increased AA in PSML and increased LTB(4) and PMNs in the lung. Lymph diversion decreased lung LTB(4) by 75% and PMNs by 40%. PSML stimulated PMN priming (11.56 +/- 1.25 vs. 3.95 +/- 0.29 nmol O(2)(-)/min; 3.75 x 10(5) cells/ml; P < 0.01) that was attenuated by LTB(4) receptor blockade (2.64 +/- 0.58; P < 0.01). AA stimulated PMNs to produce LTB(4), and AA-induced PMN priming was attenuated by LTB(4) receptor antagonism. Collectively, these data indicate that splanchnic ischemia/reperfusion activates gut PLA(2)-mediated release of AA into the lymph where it is delivered to the lungs, provoking LTB(4) production and subsequent PMN-mediated lung injury.
Collapse
Affiliation(s)
- Janeen R Jordan
- Department of Surgery, University of Colorado Denver, Denver, CO, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Gomez-Cambronero J, Di Fulvio M, Knapek K. Understanding phospholipase D (PLD) using leukocytes: PLD involvement in cell adhesion and chemotaxis. J Leukoc Biol 2007; 82:272-81. [PMID: 17431093 DOI: 10.1189/jlb.0107033] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Phospholipase D (PLD) is an enzyme that catalyzes the conversion of membrane phosphatidylcholine to choline and phosphatidic acid (PA; a second messenger). PLD is expressed in nearly all types of leukocytes and has been associated with phagocytosis, degranulation, microbial killing, and leukocyte maturation. With the application of recently developed molecular tools (i.e., expression vectors, silencing RNA, and specific antibodies), the demonstration of a key role for PLD in those and related cellular actions has contributed to a better awareness of its importance. A case in point is the recent findings that RNA interference-mediated depletion of PLD results in impaired leukocyte adhesion and chemotaxis toward a gradient of chemokines, implying that PLD is necessary for leukocyte movement. We forecast that based on results such as those, leukocytes may prove to be useful tools to unravel still-unresolved mechanistic issues in the complex biology of PLD. Three such issues are considered here: first, whether the cellular actions of PLD are mediated entirely by PA (the product of its enzymatic reaction) or whether PLD by itself interacts with other protein signaling molecules; second, the current difficulty of defining a "PA consensus site" in the various intracellular protein targets of PA; and third, the resolution of specific PLD location (upstream or downstream) in a particular effector signaling cascade. There are reasons to expect that leukocytes and their leukemic cell line counterparts will continue yielding invaluable information to cell biologists to resolve standing molecular and functional issues concerning PLD.
Collapse
Affiliation(s)
- Julian Gomez-Cambronero
- Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
| | | | | |
Collapse
|
12
|
Flamand N, Picard S, Lemieux L, Pouliot M, Bourgoin SG, Borgeat P. Effects of pyrrophenone, an inhibitor of group IVA phospholipase A2, on eicosanoid and PAF biosynthesis in human neutrophils. Br J Pharmacol 2006; 149:385-92. [PMID: 16967052 PMCID: PMC1978440 DOI: 10.1038/sj.bjp.0706879] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND PURPOSE The biosynthesis of leukotrienes (LT) and platelet-activating factor (PAF) involves the release of their respective precursors, arachidonic acid (AA) and lyso-PAF by the group IVA PLA2 (cPLA2alpha). This paper aims at characterizing the inhibitory properties of the cPLA2alpha inhibitor pyrrophenone on eicosanoids and PAF in human neutrophils (PMN). EXPERIMENTAL APPROACH Freshly isolated human PMN were activated with physiological and pharmacological agents (fMLP, PAF, exogenous AA, A23187 and thapsigargin) in presence and absence of the cPLA2alpha inhibitor pyrrophenone and biosynthesis of LT, PAF, and PGE2 was measured. KEY RESULTS Pyrrophenone potently inhibited LT, PGE2 and PAF biosynthesis in PMN with IC50s in the range of 1-20 nM. These inhibitory effects of pyrrophenone were specific (the consequence of substrate deprivation), as shown by the reversal of inhibition by exogenous AA and lyso-PAF. Comparative assessment of pyrrophenone, methyl-arachidonoyl-fluoro-phosphonate (MAFP) and arachidonoyl-trifluoromethylketone (AACOCF3) demonstrated that pyrrophenone was more specific and 100-fold more potent than MAFP and AACOCF3 for the inhibition of LT biosynthesis in A23187-activated PMN. The inhibitory effect of pyrrophenone on LT biosynthesis was reversible as LT biosynthesis was recovered when pyrrophenone-treated PMN were washed with autologous plasma. No alteration of phospholipase D (PLD) activity in fMLP-activated PMN was observed with up to 10 microM pyrrophenone, suggesting that the cPLA2alpha inhibitor does not directly inhibit PLD. CONCLUSIONS AND IMPLICATIONS Pyrrophenone is a more potent and specific cPLA2alpha inhibitor than MAFP and AACOCF3 and represents an excellent pharmacological tool to investigate the biosynthesis and the biological roles of eicosanoids and PAF.
Collapse
Affiliation(s)
- N Flamand
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
| | - S Picard
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
| | - L Lemieux
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
| | - M Pouliot
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
| | - S G Bourgoin
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
| | - P Borgeat
- Département d'anatomic et de physiologie, Centre de Recherche en Rhumatologie et Immunologie, Centre de recherche du CHUQ (CHUL), Faculté de Médecine, Université Laval Québec, Canada
- Author for correspondence:
| |
Collapse
|
13
|
Kim C, Dinauer MC. Impaired NADPH oxidase activity in Rac2-deficient murine neutrophils does not result from defective translocation of p47phox and p67phox and can be rescued by exogenous arachidonic acid. J Leukoc Biol 2006; 79:223-34. [PMID: 16275890 DOI: 10.1189/jlb.0705371] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Rac2 is a hematopoietic-specific Rho-GTPase that plays a stimulus-specific role in regulating reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and other functional responses in neutrophils. In this study, rac2-/- neutrophils were shown to have significantly decreased NADPH oxidase activity and actin remodeling in response to exogenous arachidonic acid (AA), as previously observed for phorbol 12-myristate 13-acetate (PMA) or formyl-Met-Leu-Phe (fMLP) as agonists. PMA-, fMLP-, or AA-induced translocation of p47phox and p67phox to the plasma membrane was not impaired in rac2-/- neutrophils. Combined stimulation of rac2-/- neutrophils with exogenous AA and PMA had a synergistic effect on NADPH oxidase activity, and superoxide production increased to a level that was at least as high as wild-type cells and had no effect on fMLP-elicited enzyme activity. Membrane translocation of p47phox and p67phox as well as Rac1 activation was not increased further by combined PMA and AA stimulation. Inhibitor studies were consistent with important roles for phorbol ester-activated protein kinase C (PKC) isoforms and an atypical isoform, PKCzeta, in superoxide production by wild-type and rac2-/- neutrophils stimulated with AA and PMA. In addition, PMA-stimulated release of AA and cytoplasmic phospholipase A2 expression in rac2-/- neutrophils were similar to wild-type, suggesting that deficient AA production by PMA-stimulated rac2-/- neutrophils does not explain the effect of exogenous AA on oxidase activity. Although not required for translocation of p47phox and p67phox, Rac2 is necessary for optimal activity of the assembled oxidase complex, an effect that can be replaced by exogenous AA, which may act directly or via an exogenous AA-induced mediator.
Collapse
Affiliation(s)
- Chaekyun Kim
- Herman B. Wells Center for Pediatric Research, Department of Pediatrics (Hematology/Oncology), James Whitcomb Riley Hospital for Children, Indiana University Medical Center, Indianapolis, IN, USA
| | | |
Collapse
|
14
|
Fortin A, Harbour D, Fernandes M, Borgeat P, Bourgoin S. Differential expression of adenosine receptors in human neutrophils: up-regulation by specific Th1 cytokines and lipopolysaccharide. J Leukoc Biol 2005; 79:574-85. [PMID: 16387843 DOI: 10.1189/jlb.0505249] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Four types of adenosine receptors have been identified in different tissues and cell types, namely, A1, A2A, A2B, and A3 receptors. We report that A2AR but not A2BR mRNA in freshly isolated polymorphonuclear neutrophils (PMN) is maximally up-regulated after 4 h stimulation with lipopolysaccharide (LPS) or tumor necrosis factor alpha (TNF-alpha) and to a lesser extent, with interleukin (IL)-1beta. These effects were maintained up to 21 h. Consistent with changes in A2AR mRNA expression, up-regulation of A2AR protein was also detected after 4 h of LPS or TNF-alpha exposure. Up-regulation of A2AR protein expression was transient and returned to near basal levels after 12 h or 16 h stimulation with TNF-alpha or LPS, respectively. Conversely, IL-1beta failed to promote A2AR protein expression. Suppression of thapsigargin-induced leukotriene synthesis by the selective A2AR agonist CGS-21680 was found to be more pronounced when PMN were cultured for 4 h with LPS or TNF-alpha. In contrast, the up-regulation of A2AR has no impact on CGS-21680-induced inhibition of phospholipase D activation and superoxide production in response to formyl-Met-Leu-Phe. These results demonstrate that the A2AR is up-regulated by specific T helper cell type 1 cytokines and LPS. Although this could represent a potential feedback mechanism to control inflammation, the effect of A2AR up-regulation varied depending on the stimulus used to stimulate PMN functional responses after their incubation with proinflammatory mediators.
Collapse
Affiliation(s)
- Andrée Fortin
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, Pavillon C.H.U.L., 2705 Blvd. Laurier, Sainte-Foy, Québec, Canada G1V 4G2
| | | | | | | | | |
Collapse
|
15
|
Flamand N, Lefebvre J, Surette ME, Picard S, Borgeat P. Arachidonic acid regulates the translocation of 5-lipoxygenase to the nuclear membranes in human neutrophils. J Biol Chem 2005; 281:129-36. [PMID: 16275640 DOI: 10.1074/jbc.m506513200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Elevation of the intracellular cAMP concentration in agonist-activated human neutrophils (PMN) leads to the concomitant inhibitions of arachidonic acid (AA) release, 5-lipoxygenase (5-LO) translocation, and leukotriene (LT) biosynthesis. We report herein that exogenous AA completely prevents cAMP-dependent inhibition of 5-LO translocation and LT biosynthesis in agonist-activated PMN. Moreover, the group IVA phospholipase A2 inhibitor pyrrophenone and the MEK inhibitor U-0126 inhibited AA release and 5-LO translocation in activated PMN, and these effects were also prevented by exogenous AA, demonstrating a functional link between AA release and 5-LO translocation. Polyunsaturated fatty acids of the C18 and C20 series containing at least three double bonds located from carbon 9 (or closer to the carboxyl group) were equally effective as AA in restoring 5-LO translocation in pyrrophenone-treated agonist-activated PMN. Importantly, experiments with the 5-LO-activating protein inhibitor MK-0591 and the intracellular Ca2+ chelator BAPTA-AM demonstrated that the AA-regulated 5-LO translocation is FLAP- and Ca2+-dependent. Finally, the redox and competitive 5-LO inhibitors L-685,015, L-739,010, and L-702,539 (but not cyclooxygenase inhibitors) efficiently substituted for AA to reverse the pyrrophenone inhibition of 5-LO translocation, indicating that the site of regulation of 5-LO translocation by AA is at or in the vicinity of the catalytic site. This report demonstrates that AA regulates the translocation of 5-LO in human PMN and unravels a novel mechanism of the cAMP-mediated inhibition of LT biosynthesis.
Collapse
Affiliation(s)
- Nicolas Flamand
- Centre de Recherche en Rhumatologie et Immunologie, Université Laval, Québec, Canada G1V 4G2
| | | | | | | | | |
Collapse
|
16
|
Flamand N, Plante H, Picard S, Laviolette M, Borgeat P. Histamine-induced inhibition of leukotriene biosynthesis in human neutrophils: involvement of the H2 receptor and cAMP. Br J Pharmacol 2004; 141:552-61. [PMID: 14744809 PMCID: PMC1574237 DOI: 10.1038/sj.bjp.0705654] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
1. Histamine is generally regarded as a pro-inflammatory mediator in diseases such as allergy and asthma. A growing number of studies, however, suggest that this autacoid is also involved in the downregulation of human polymorphonuclear leukocyte (PMN) functions and inflammatory responses through activation of the Gs-coupled histamine H(2) receptor. 2. We report here that histamine inhibits thapsigargin- and ligand (PAF and fMLP)-induced leukotriene (LT) biosynthesis in human PMN in a dose-dependent manner. 3. The suppressive effect of histamine on LT biosynthesis was abrogated by the histamine H(2) receptor antagonists cimetidine, ranitidine, and tiotidine. In contrast, the histamine H(1), H(3), and H(4) receptor antagonists used in this study were ineffective in counteracting the inhibitory effect of histamine on the biosynthesis of LT in activated human PMN. 4. The inhibition of LT biosynthesis by histamine was characterized by decreased arachidonic acid release and 5-lipoxygenase translocation to the nuclear membrane. 5. Incubation of PMN with the cAMP-dependent protein kinase (PKA) inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide prevented the inhibitory effect of histamine on LT biosynthesis, suggesting an important role for PKA in this effect of histamine on LT biosynthesis in PMN. 6. These data provide the first evidences that, similarly to adenosine and prostaglandin E(2), histamine is a potent suppressor of LT biosynthesis, and support the concept that histamine may play a dual role in the regulation of inflammation.
Collapse
Affiliation(s)
- Nicolas Flamand
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ and Faculté de Médecine, CHUL, Office T1-49, 2705 Laurier, Sainte-Foy, Université Laval, Québec, Canada G1V 4G2
| | - Hendrick Plante
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ and Faculté de Médecine, CHUL, Office T1-49, 2705 Laurier, Sainte-Foy, Université Laval, Québec, Canada G1V 4G2
| | - Serge Picard
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ and Faculté de Médecine, CHUL, Office T1-49, 2705 Laurier, Sainte-Foy, Université Laval, Québec, Canada G1V 4G2
| | - Michel Laviolette
- Unité de Recherche en Pneumologie, Institut Universitaire de Cardiologie et Pneumologie de l'Université Laval, Québec, Canada
| | - Pierre Borgeat
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ and Faculté de Médecine, CHUL, Office T1-49, 2705 Laurier, Sainte-Foy, Université Laval, Québec, Canada G1V 4G2
- Author for correspondence:
| |
Collapse
|