1
|
Malavige GN, Ogg GS. Molecular mechanisms in the pathogenesis of dengue infections. Trends Mol Med 2024; 30:484-498. [PMID: 38582622 DOI: 10.1016/j.molmed.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/08/2024]
Abstract
Dengue is the most rapidly emerging climate-sensitive infection, and morbidity/mortality and disease incidence are rising markedly, leading to healthcare systems being overwhelmed. There are currently no specific treatments for dengue or prognostic markers to identify those who will progress to severe disease. Owing to an increase in the burden of illness and a change in epidemiology, many patients experience severe disease. Our limited understanding of the complex mechanisms of disease pathogenesis has significantly hampered the development of safe and effective treatments, vaccines, and biomarkers. We discuss the molecular mechanisms of dengue pathogenesis, the gaps in our knowledge, and recent advances, as well as the most crucial questions to be answered to enable the development of therapeutics, biomarkers, and vaccines.
Collapse
Affiliation(s)
- Gathsaurie Neelika Malavige
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka; Medical Research Council (MRC) Translational Immune Discovery Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
| | - Graham S Ogg
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka; Medical Research Council (MRC) Translational Immune Discovery Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
2
|
Silva T, Gomes L, Jeewandara C, Ogg GS, Malavige GN. Dengue NS1 induces phospholipase A 2 enzyme activity, prostaglandins, and inflammatory cytokines in monocytes. Antiviral Res 2022; 202:105312. [PMID: 35395274 DOI: 10.1016/j.antiviral.2022.105312] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/24/2022] [Accepted: 03/27/2022] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Dengue virus (DENV) NS1 is a non-structural secretory protein associated with severe disease and known to cause vascular leak leading to dengue haemorrhagic fever (DHF). As phospholipases A2 (PLA2) enzymes, platelet activating factor, and leukotrienes are elevated in dengue, we sought to investigate whether NS1 potentially contributes to disease pathogenesis by inducing PLA2s. METHODS THP-1 cells and primary human monocytes of healthy adults (n = 6) were co-cultured with DENV1 NS1, LPS and media alone. The latter two were used as positive and negative controls. The cell culture supernatants and lysates were harvested at 12 and 24 h and the activity of secretory and cytoplasmic PLA2, prostaglandins (PGE2 and PGD2) were measured by ELISA and cytokines levels were measured using a magnetic Luminex assay. Expression of PLA2G4A, PLA2G2A, PLA2G5, PLA2G10, PLA2G7, GAPDH, NLRP3 and DDX58 genes were assessed using quantitative RT-PCR. RESULTS cPLA2 (p = 0.005), sPLA2 (p = 0.04), PGE2 metabolite (p = 0.02) and PGD2 metabolite (p = 0.04) levels were significantly higher at 12 h in monocytes co-cultured with NS1. Levels of IP-10 (p = 0.005) and IL-10 (p = 0.009) was significantly higher at 24 h, whereas IFNα level was significantly higher (p = 0.013) only at 12 h. IL-1β (p = 0.028 and p = 0.031) and TNFα (p = 0.007 and p = 0.011) showed significantly higher levels at both time points. At 12 h significant upregulation of PLA2G4A (p < 0.0001) was seen, whereas PLA2G7 (p = <0.0001), NLRP3 (p = 0.0009) and DDX58 (p = 0.0056) were significantly downregulated. This pattern changed at 24 h with PLA2G4A (p = 0.0069) showing a marked downregulation and PLA2G7, DDX58 and NLRP3 showing an upregulation, although not significant. CONCLUSION Dengue NS1 induces the production of PLA2 enzymes, prostaglandins and inflammatory cytokines from primary human monocytes, which could play a role in vascular leak in dengue.
Collapse
Affiliation(s)
- Tehani Silva
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, University of Sri Jayewardenepura, Nugegoda, Sri Lanka; General Sir John Kotelawala Defence University, Rathmalana, Sri Lanka
| | - Laksiri Gomes
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Chandima Jeewandara
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Graham S Ogg
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Oxford NIHR Biomedical Research Centre and University of Oxford, OX3 9DS, UK
| | - Gathsaurie Neelika Malavige
- Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, University of Sri Jayewardenepura, Nugegoda, Sri Lanka; MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Oxford NIHR Biomedical Research Centre and University of Oxford, OX3 9DS, UK.
| |
Collapse
|
3
|
Watanabe K, Taketomi Y, Miki Y, Kugiyama K, Murakami M. Group V secreted phospholipase A 2 plays a protective role against aortic dissection. J Biol Chem 2020; 295:10092-10111. [PMID: 32482892 DOI: 10.1074/jbc.ra120.013753] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/22/2020] [Indexed: 12/23/2022] Open
Abstract
Aortic dissection is a life-threatening aortopathy involving separation of the aortic wall, whose underlying mechanisms are still incompletely understood. Epidemiological evidence suggests that unsaturated fatty acids improve cardiovascular health. Here, using quantitative RT-PCR, histological analyses, magnetic cell sorting and flow cytometry assays, and MS-based lipidomics, we show that the activity of a lipid-metabolizing enzyme, secreted phospholipase A2 group V (sPLA2-V), protects against aortic dissection by endogenously mobilizing vasoprotective lipids. Global and endothelial cell-specific sPLA2-V-deficient mice frequently developed aortic dissection shortly after infusion of angiotensin II (AT-II). We observed that in the AT-II-treated aorta, endothelial sPLA2-V mobilized oleic and linoleic acids, which attenuated endoplasmic reticulum stress, increased the expression of lysyl oxidase, and thereby stabilized the extracellular matrix in the aorta. Of note, dietary supplementation with oleic or linoleic acid reversed the increased susceptibility of sPLA2-V-deficient mice to aortic dissection. These findings reveal an unexplored functional link between sPLA2-driven phospholipid metabolism and aortic stability, possibly contributing to the development of improved diagnostic and/or therapeutic strategies for preventing aortic dissection.
Collapse
Affiliation(s)
- Kazuhiro Watanabe
- Department of Internal Medicine II, University of Yamanashi, Department of Internal Medicine II, Chuo, Yamanashi Japan.,Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Kiyotaka Kugiyama
- Department of Internal Medicine II, University of Yamanashi, Department of Internal Medicine II, Chuo, Yamanashi Japan .,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan .,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.,FORCE, Japan Agency for Medical Research and Development, Tokyo, Japan
| |
Collapse
|
4
|
Malavige GN, Ogg GS. Pathogenesis of vascular leak in dengue virus infection. Immunology 2017; 151:261-269. [PMID: 28437586 DOI: 10.1111/imm.12748] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/26/2017] [Accepted: 04/17/2017] [Indexed: 12/31/2022] Open
Abstract
Endothelial dysfunction leading to vascular leak is the hallmark of severe dengue. Vascular leak typically becomes clinically evident 3-6 days after the onset of illness, which is known as the critical phase. This critical phase follows the period of peak viraemia, and lasts for 24-48 hr and usually shows rapid and complete reversal, suggesting that it is likely to occur as a result of inflammatory mediators, rather than infection of the endothelium. Cytokines such as tumour necrosis factor-α, which are known to be elevated in the critical phase of dengue, are likely to be contributing factors. Dengue NS1, a soluble viral protein, has also been shown to disrupt the endothelial glycocalyx and thus contribute to vascular leak, although there appears to be a discordance between the timing of NS1 antigenaemia and occurrence of vascular leak. In addition, many inflammatory lipid mediators are elevated in acute dengue viral infection such as platelet activating factor (PAF) and leukotrienes. Furthermore, many other inflammatory mediators such as vascular endothelial growth factor and angiopoietin-2 have been shown to be elevated in patients with dengue haemorrhagic fever, exerting their action in part by inducing the activity of phospholipases, which have diverse inflammatory effects including generation of PAF. Platelets have also been shown to significantly contribute to endothelial dysfunction by production of interleukin-1β through activation of the NLRP3 inflammasome and also by inducing production of inflammatory cytokines by monocytes. Drugs that block down-stream immunological mediator pathways such as PAF may also be beneficial in the treatment of severe disease.
Collapse
Affiliation(s)
- Gathsaurie Neelika Malavige
- Centre for Dengue Research, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.,MRC Human Immunology Unit, Radcliffe Department of Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Graham S Ogg
- MRC Human Immunology Unit, Radcliffe Department of Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
5
|
Jeewandara C, Gomes L, Udari S, Paranavitane SA, Shyamali NLA, Ogg GS, Malavige GN. Secretory phospholipase A2 in the pathogenesis of acute dengue infection. IMMUNITY INFLAMMATION AND DISEASE 2016; 5:7-15. [PMID: 28250920 PMCID: PMC5322161 DOI: 10.1002/iid3.135] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 12/15/2022]
Abstract
Introduction Platelet activating factor (PAF) is an important mediator of vascular leak in acute dengue. Phospholipase A2s (PLA2) are inflammatory lipid enzymes that generate and regulate PAF and other mediators associated with mast cells. We sought to investigate if mast cell activation and increases in secretory sPLA2s are associated with an increase in PAF and occurrence of dengue haemorrhagic fever (DHF). Methods The changes in the levels of mast cell tryptase, PAF and the activity of sPLA2 were determined throughout the course of illness in 13 adult patients with DHF, and 30 patients with dengue fever (DF). Results We found that sPLA2 activity was significantly higher in patients with DHF when compared to those with DF, during the first 120 h of clinical illness. sPLA2 activity was significantly associated with PAF levels, which were also significantly higher in patients with DHF. Although levels of mast cell tryptase were higher in patients with DHF, the difference was not significant, and the levels were not above the reference ranges. sPLA2 activity significantly correlated with the degree of viraemia in patients with DHF but not in those with DF. Conclusion sPLA2 appears to play an important role in the pathogenesis of dengue. Since its activity is significantly increased during the early phase of infection in patients with DHF, this suggests that understanding the underlying mechanisms may provide opportunities for early intervention.
Collapse
Affiliation(s)
| | - Laksiri Gomes
- Centre for Dengue Research University of Sri Jayawardanapura Sri Lanka
| | - Sukhitha Udari
- Centre for Dengue Research University of Sri Jayawardanapura Sri Lanka
| | - S A Paranavitane
- Centre for Dengue Research University of Sri Jayawardanapura Sri Lanka
| | - N L A Shyamali
- Faculty of Medical Sciences Department of Medicine University of Sri Jayawardanapura Sri Lanka
| | - Graham S Ogg
- MRC Human Immunology Unit NIHR Biomedical Research Centre Weatherall Institute of Molecular Medicine Oxford
| | - Gathsaurie Neelika Malavige
- Centre for Dengue ResearchUniversity of Sri JayawardanapuraSri Lanka; MRC Human Immunology UnitNIHR Biomedical Research CentreWeatherall Institute of Molecular MedicineOxford
| |
Collapse
|
6
|
In vitro anti-Plasmodium falciparum properties of the full set of human secreted phospholipases A2. Infect Immun 2015; 83:2453-65. [PMID: 25824843 DOI: 10.1128/iai.02474-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 03/25/2015] [Indexed: 01/23/2023] Open
Abstract
We have previously shown that secreted phospholipases A2 (sPLA2s) from animal venoms inhibit the in vitro development of Plasmodium falciparum, the agent of malaria. In addition, the inflammatory-type human group IIA (hGIIA) sPLA2 circulates at high levels in the serum of malaria patients. However, the role of the different human sPLA2s in host defense against P. falciparum has not been investigated. We show here that 4 out of 10 human sPLA2s, namely, hGX, hGIIF, hGIII, and hGV, exhibit potent in vitro anti-Plasmodium properties with half-maximal inhibitory concentrations (IC50s) of 2.9 ± 2.4, 10.7 ± 2.1, 16.5 ± 9.7, and 94.2 ± 41.9 nM, respectively. Other human sPLA2s, including hGIIA, are inactive. The inhibition is dependent on sPLA2 catalytic activity and primarily due to hydrolysis of plasma lipoproteins from the parasite culture. Accordingly, purified lipoproteins that have been prehydrolyzed by hGX, hGIIF, hGIII, and hGV are more toxic to P. falciparum than native lipoproteins. However, the total enzymatic activities of human sPLA2s on purified lipoproteins or plasma did not reflect their inhibitory activities on P. falciparum. For instance, hGIIF is 9-fold more toxic than hGV but releases a lower quantity of nonesterified fatty acids (NEFAs). Lipidomic analyses of released NEFAs from lipoproteins demonstrate that sPLA2s with anti-Plasmodium properties are those that release polyunsaturated fatty acids (PUFAs), with hGIIF being the most selective enzyme. NEFAs purified from lipoproteins hydrolyzed by hGIIF were more potent at inhibiting P. falciparum than those from hGV, and PUFA-enriched liposomes hydrolyzed by sPLA2s were highly toxic, demonstrating the critical role of PUFAs. The selectivity of sPLA2s toward low- and high-density (LDL and HDL, respectively) lipoproteins and their ability to directly attack parasitized erythrocytes further explain their anti-Plasmodium activity. Together, our findings indicate that 4 human sPLA2s are active against P. falciparum in vitro and pave the way to future investigations on their in vivo contribution in malaria pathophysiology.
Collapse
|
7
|
Rousseau M, Belleannee C, Duchez AC, Cloutier N, Levesque T, Jacques F, Perron J, Nigrovic PA, Dieude M, Hebert MJ, Gelb MH, Boilard E. Detection and quantification of microparticles from different cellular lineages using flow cytometry. Evaluation of the impact of secreted phospholipase A2 on microparticle assessment. PLoS One 2015; 10:e0116812. [PMID: 25587983 PMCID: PMC4294685 DOI: 10.1371/journal.pone.0116812] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 12/15/2014] [Indexed: 11/20/2022] Open
Abstract
Microparticles, also called microvesicles, are submicron extracellular vesicles produced by plasma membrane budding and shedding recognized as key actors in numerous physio(patho)logical processes. Since they can be released by virtually any cell lineages and are retrieved in biological fluids, microparticles appear as potent biomarkers. However, the small dimensions of microparticles and soluble factors present in body fluids can considerably impede their quantification. Here, flow cytometry with improved methodology for microparticle resolution was used to detect microparticles of human and mouse species generated from platelets, red blood cells, endothelial cells, apoptotic thymocytes and cells from the male reproductive tract. A family of soluble proteins, the secreted phospholipases A2 (sPLA2), comprises enzymes concomitantly expressed with microparticles in biological fluids and that catalyze the hydrolysis of membrane phospholipids. As sPLA2 can hydrolyze phosphatidylserine, a phospholipid frequently used to assess microparticles, and might even clear microparticles, we further considered the impact of relevant sPLA2 enzymes, sPLA2 group IIA, V and X, on microparticle quantification. We observed that if enriched in fluids, certain sPLA2 enzymes impair the quantification of microparticles depending on the species studied, the source of microparticles and the means of detection employed (surface phosphatidylserine or protein antigen detection). This study provides analytical considerations for appropriate interpretation of microparticle cytofluorometric measurements in biological samples containing sPLA2 enzymes.
Collapse
Affiliation(s)
- Matthieu Rousseau
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l’Université Laval, Québec, QC, Canada
| | - Clemence Belleannee
- Centre de Recherche du CHUQ and Département d’Obstétrique-Gynécologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Anne-Claire Duchez
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l’Université Laval, Québec, QC, Canada
| | - Nathalie Cloutier
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l’Université Laval, Québec, QC, Canada
| | - Tania Levesque
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l’Université Laval, Québec, QC, Canada
| | | | - Jean Perron
- Centre Hospitalier Universitaire de Québec, Québec, Canada
| | - Peter A. Nigrovic
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States of America
- Division of Immunology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Melanie Dieude
- Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Marie-Josee Hebert
- Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Michael H. Gelb
- Department of Chemistry, University of Washington, Seattle, WA, United States of America
| | - Eric Boilard
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l’Université Laval, Québec, QC, Canada
- * E-mail:
| |
Collapse
|
8
|
Abstract
At least 468 individual genes have been manipulated by molecular methods to study their effects on the initiation, promotion, and progression of atherosclerosis. Most clinicians and many investigators, even in related disciplines, find many of these genes and the related pathways entirely foreign. Medical schools generally do not attempt to incorporate the relevant molecular biology into their curriculum. A number of key signaling pathways are highly relevant to atherogenesis and are presented to provide a context for the gene manipulations summarized herein. The pathways include the following: the insulin receptor (and other receptor tyrosine kinases); Ras and MAPK activation; TNF-α and related family members leading to activation of NF-κB; effects of reactive oxygen species (ROS) on signaling; endothelial adaptations to flow including G protein-coupled receptor (GPCR) and integrin-related signaling; activation of endothelial and other cells by modified lipoproteins; purinergic signaling; control of leukocyte adhesion to endothelium, migration, and further activation; foam cell formation; and macrophage and vascular smooth muscle cell signaling related to proliferation, efferocytosis, and apoptosis. This review is intended primarily as an introduction to these key signaling pathways. They have become the focus of modern atherosclerosis research and will undoubtedly provide a rich resource for future innovation toward intervention and prevention of the number one cause of death in the modern world.
Collapse
Affiliation(s)
- Paul N Hopkins
- Cardiovascular Genetics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
| |
Collapse
|
9
|
Meliton AY, Muñoz NM, Meliton LN, Birukova AA, Leff AR, Birukov KG. Mechanical induction of group V phospholipase A(2) causes lung inflammation and acute lung injury. Am J Physiol Lung Cell Mol Physiol 2013; 304:L689-700. [PMID: 23525785 DOI: 10.1152/ajplung.00047.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ventilation at high tidal volume may cause lung inflammation and barrier dysfunction that culminates in ventilator-induced lung injury (VILI). However, the mechanisms by which mechanical stimulation triggers the inflammatory response have not been fully elucidated. This study tested the hypothesis that onset of VILI is triggered by activation of secretory group V phospholipase A(2) (gVPLA2) in pulmonary vascular endothelium exposed to excessive mechanical stretch. High-magnitude cyclic stretch (18% CS) increased expression and surface exposure of gVPLA2 in human pulmonary endothelial cells (EC). CS-induced gVPLA2 activation was required for activation of ICAM-1 expression and polymorphonuclear neutrophil (PMN) adhesion to CS-preconditioned EC. By contrast, physiological CS (5% CS) had no effect on gVPLA2 activation or EC-PMN adhesion. CS-induced ICAM-1 expression and EC-PMN adhesion were attenuated by the gVPLA2-blocking antibody (MCL-3G1), general inhibitor of soluble PLA2, LY311727, or siRNA-induced EC gVPLA2 knockdown. In vivo, ventilator-induced lung leukocyte recruitment, cell and protein accumulation in the alveolar space, and total lung myeloperoxidase activity were strongly suppressed in gVPLA2 mouse knockout model or upon administration of MCL-3G1. These results demonstrate a novel role for gVPLA2 as the downstream effector of pathological mechanical stretch leading to an inflammatory response associated with VILI.
Collapse
Affiliation(s)
- Angelo Y Meliton
- Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | | | | | | | | | | |
Collapse
|
10
|
Chini M, Tsoupras AB, Mangafas N, Tsogas N, Papakonstantinou VD, Fragopoulou E, Antonopoulou S, Gargalianos P, Demopoulos CA, Lazanas MC. Effects of highly active antiretroviral therapy on platelet activating factor metabolism in naive HIV-infected patients: ii) study of the abacavir/lamivudine/efavirenz HAART regimen. Int J Immunopathol Pharmacol 2012; 25:247-58. [PMID: 22507337 DOI: 10.1177/039463201202500127] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Human Immunodeficiency Virus (HIV)-infected patients are at increased risk for cardiovascular diseases partly due to chronic inflammation. Some antiretroviral drugs and Highly Active Anti-Retroviral Therapy (HAART) regimens seem to be related and amplify this increased risk, especially the ones containing abacavir. Platelet-Activating-Factor (PAF) is a potent inflammatory mediator that is implicated in both cardiovascular diseases and HIV-related manifestations. Our objective is to study the in vivo effect of the abacavir/lamivudine/efavirenz first-line HAART regimen on PAF metabolism in HIV-infected patients. The specific activities of PAF basic biosynthetic enzymes in leukocytes and platelets, PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), but also those of PAF-basic catabolic enzymes, PAF acetylhydrolase (PAF-AH) in leukocytes and platelets and Lipoprotein-associated-Phospholipase-A2 (LpPLA2) in plasma, were measured in blood samples of 10 asymptomatic naïve male HIV-infected patients just before and after 1, 3 and 6 months of treatment. CD4 cell counts, viral load and several biochemical markers were also measured in the same blood samples of these patients. The repeated ANOVA measures and the Pearson r criterion were used for studying statistical differences and correlations - partial correlations respectively. Even though viral load was decreased and CD4 cell counts were beneficially increased after treatment with the abacavir/lamivudine/efavirenz regimen, the main enzyme of the remodelling PAF-synthesis that is implicated in pro-atherogenic inflammatory procedures, Lyso-PAF-AT activity, was increased at 3 months of treatment in both leukocytes and platelets, while the main enzyme of PAF-degradation, PAF-AH, was increased as a response only in leukocytes at the 3rd month. Although the abacavir/lamivudine/efavirenz HAART regimen exhibits very efficient antiretroviral activities, on the other hand it induces an in vivo transient increase in the inflammation-related remodeling PAF-biosynthetic pathway. This finding supports the hypothesis of inflammation-mediated increased cardiovascular risk in HIV-infected patients during the first months of abacavir-containing HAART.
Collapse
Affiliation(s)
- M Chini
- 3rd Internal Medicine Department-Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Dumas E, Martel C, Neagoe PE, Bonnefoy A, Sirois MG. Angiopoietin-1 but not angiopoietin-2 promotes neutrophil viability: Role of interleukin-8 and platelet-activating factor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:358-67. [DOI: 10.1016/j.bbamcr.2011.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 12/06/2011] [Accepted: 12/07/2011] [Indexed: 01/15/2023]
|
12
|
Salmeri M, Motta C, Mastrojeni S, Amodeo A, Anfuso CD, Giurdanella G, Morello A, Alberghina M, Toscano MA, Lupo G. Involvement of PKCα-MAPK/ERK-phospholipase A(2) pathway in the Escherichia coli invasion of brain microvascular endothelial cells. Neurosci Lett 2012; 511:33-7. [PMID: 22306096 DOI: 10.1016/j.neulet.2012.01.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 12/19/2011] [Accepted: 01/17/2012] [Indexed: 01/12/2023]
Abstract
Escherichia coli K1 is the most common Gram-negative organism that causes neonatal meningitis following penetration of the blood-brain barrier. In the present study we demonstrated the involvement of cytosolic (cPLA(2)) and calcium-independent phospholipase A(2) (iPLA(2)) and the contribution of cyclooxygenase-2 products in E. coli invasion of microvascular endothelial cells. The traversal of bacteria did not determine trans-endothelial electrical resistance (TEER) and ZO-1 expression changes and was reduced by PLA(2)s siRNA. cPLA(2) and iPLA(2) enzyme activities and cPLA(2) phosphorylation were stimulated after E. coli incubation and were attenuated by PLA(2), PI3-K, ERK 1/2 inhibitors. Our results demonstrate the role of PKCα/ERK/MAPK signaling pathways in governing the E. coli penetration into the brain.
Collapse
Affiliation(s)
- Mario Salmeri
- Dept. Scienze Bio-Mediche, University of Catania, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
sPLA2-V inhibits EPCR anticoagulant and antiapoptotic properties by accommodating lysophosphatidylcholine or PAF in the hydrophobic groove. Blood 2011; 119:2914-21. [PMID: 22167755 DOI: 10.1182/blood-2011-05-353409] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The endothelial protein C receptor (EPCR) plays an important role in cardiovascular disease by binding protein C/activated protein C (APC). EPCR structure contains a hydrophobic groove filled with an unknown phospholipid needed to perform its function. It has not been established whether lipid exchange takes place in EPCR as a regulatory mechanism of its activity. Our objective was to identify this phospholipid and to explore the possibility of lipid exchange as a regulatory mechanism of EPCR activity driven by the endothelially expressed secretory group V phospholipase A(2) (sPLA(2)-V). We identified phosphatidylcholine (PCh) as the major phospholipid bound to human soluble EPCR (sEPCR). PCh in EPCR could be exchanged for lysophosphatidylcholine (lysoPCh) and platelet activating factor (PAF). Remarkably, lysoPCh and PAF impaired the protein C binding ability of sEPCR. Inhibition of sPLA(2)-V, responsible for lysoPCh and PAF generation, improved APC binding to endothelial cells. EPCR-dependent protein C activation and APC antiapoptotic effect were thus significantly enhanced. In contrast, endothelial cell supplementation with sPLA(2)-V inhibited both APC generation and its antiapoptotic effects. We conclude that APC generation and function can be modulated by changes in phospholipid occupancy of its endothelial cell receptor.
Collapse
|
14
|
Tsoupras AB, Chini M, Mangafas N, Tsogas N, Stamatakis G, Tsantila N, Fragopoulou E, Antonopoulou S, Gargalianos P, Demopoulos CA, Lazanas MC. Platelet-Activating Factor and Its Basic Metabolic Enzymes in Blood of Naive HIV-Infected Patients. Angiology 2011; 63:343-52. [DOI: 10.1177/0003319711420608] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Maria Chini
- 3rd Internal Medicine Department, Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - Nikos Mangafas
- 3rd Internal Medicine Department, Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - Nikos Tsogas
- 3rd Internal Medicine Department, Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| | - George Stamatakis
- Department of Chemistry, National and Kapodistrian University of Athens, Greece
| | - Nektaria Tsantila
- Department of Chemistry, National and Kapodistrian University of Athens, Greece
| | - Elizabeth Fragopoulou
- Department of Dietetics and Nutritional Science, Harokopio University, Athens, Greece
| | - Smaragdi Antonopoulou
- Department of Dietetics and Nutritional Science, Harokopio University, Athens, Greece
| | - Panagiotis Gargalianos
- 1st Internal Medicine Department, Infectious Diseases Unit, “G. Gennimatas” Hospital, Athens, Greece
| | | | - Marios C. Lazanas
- 3rd Internal Medicine Department, Infectious Diseases Unit, Red Cross General Hospital, Athens, Greece
| |
Collapse
|
15
|
Alberghina M. Phospholipase A2: New lessons from endothelial cells. Microvasc Res 2010; 80:280-5. [DOI: 10.1016/j.mvr.2010.03.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/24/2010] [Accepted: 03/24/2010] [Indexed: 01/05/2023]
|
16
|
Lapointe S, Brkovic A, Cloutier I, Tanguay JF, Arm JP, Sirois MG. Group V secreted phospholipase A2 contributes to LPS-induced leukocyte recruitment. J Cell Physiol 2010; 224:127-34. [PMID: 20232296 DOI: 10.1002/jcp.22106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Secreted phospholipases A(2) (sPLA(2)s) are well known for their contribution in the biosynthesis of inflammatory eicosanoids. These enzymes also participate in the inflammatory process by regulating chemokine production and protein expression of adhesion molecules. The majority of sPLA(2) isoforms are up-regulated by proinflammatory stimuli such as bacterial lipopolysaccharide (LPS), which predominantly increases the expression of group V sPLA(2) (sPLA(2)-V). Furthermore, it has recently been shown that sPLA(2)-V is a critical messenger in the regulation of cell migration during allergic airway responsiveness. Herein, we investigated the effect of sPLA(2)-V on LPS-mediated leukocyte recruitment and its capacity to modulate adhesion molecule expression. We conducted our study in the murine air pouch model, using sPLA(2)-V null mice (sPLA(2)-V(-/-)) and control wild-type (WT) littermates. We observed that LPS (1 microg/ml)-mediated leukocyte emigration in sPLA(2)-V(-/-) was attenuated by 52% and 86% upon 6 and 12 h of treatment respectively, as compared to WT mice. In WT mice, treatment with the cell-permeable sPLA(2) inhibitor (12-epi-scalaradial; SLD) reduced LPS-mediated leukocyte recruitment by 67%, but had no additional inhibitory effect in sPLA(2)-V(-/-) mice. Protein analyses from the air pouch skin were carried out upon LPS-challenge, and the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were both significantly reduced in sPLA(2)-V(-/-) mice as compared to control WT mice. Together, our data demonstrate the role of sPLA(2)-V in LPS-induced ICAM-1 and VCAM-1 protein overexpression and leukocyte recruitment, supporting the contribution of sPLA(2)-V in the development of inflammatory innate immune responses.
Collapse
Affiliation(s)
- Stéphanie Lapointe
- Research Centre, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada
| | | | | | | | | | | |
Collapse
|
17
|
PKCα-MAPK/ERK-phospholipase A2 signaling is required for human melanoma-enhanced brain endothelial cell proliferation and motility. Microvasc Res 2009; 78:338-57. [DOI: 10.1016/j.mvr.2009.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 07/08/2009] [Accepted: 09/01/2009] [Indexed: 12/28/2022]
|
18
|
Richard D, Wolf C, Barbe U, Kefi K, Bausero P, Visioli F. Docosahexaenoic acid down-regulates endothelial Nox 4 through a sPLA2 signalling pathway. Biochem Biophys Res Commun 2009; 389:516-22. [PMID: 19737538 DOI: 10.1016/j.bbrc.2009.09.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 09/03/2009] [Indexed: 12/22/2022]
Abstract
We investigated the anti-inflammatory and antioxidant activities of docosahexaenoic acid (DHA) by evaluating its modulation of the two enzymes most involved in vascular inflammation, i.e. endothelial secreted phospholipase A(2) (sPLA(2)) and NADPH oxidase 4 (Nox) 4. Exposure of human aortic endothelial cells (HAECs) to DHA led to its preferential incorporation into outer leaflet phospholipids. Pre-treatment with DHA abolished HAECs stimulation induced by A23187 and Ang II, whereas the effects on IL-1beta treatment were less pronounced. Group V sPLA(2) RNA was similarly modulated by DHA supplementation. In addition, DHA decreased Nox 4 expression and activity; this effect was associated with reduced production of reactive oxygen species. Further, the use of specific inhibitors allowed demonstrating that group V sPLA(2) is involved in the down-regulation of Nox 4 expression and activity by DHA. This interplay is mediated by ERK and PKC.
Collapse
Affiliation(s)
- Doriane Richard
- Laboratory of Micronutrients and Cardiovascular Disease, Université Pierre et Marie Curie, Paris 6, France
| | | | | | | | | | | |
Collapse
|
19
|
Sterin M, Ringel I, Lecht S, Lelkes PI, Lazarovici P. 31P magnetic resonance spectroscopy of endothelial cells grown in three-dimensional matrigel construct as an enabling platform technology: I. The effect of glial cells and valproic acid on phosphometabolite levels. ACTA ACUST UNITED AC 2009; 15:288-98. [PMID: 19065320 DOI: 10.1080/10623320802487841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Very few studies describe endothelial cell (EC) properties under three-dimensional (3D) conditions using (31)P magnetic resonance spectroscopy (MRS). The authors developed a model in which living ECs growing in Matrigel threads (3D conditions) for 5 days are monitored by (31)P MRS, providing the fingerprint of the major EC phosphometabolites. Organic extracts of membranal phospholipids were also analyzed by (31)P MRS. For comparison and as a model for two-dimensional (2D) tissue culture conditions, (31)P MRS spectra of aqueous extracts of EC phosphometabolites grown under 2D conditions were also evaluated. The phosphometabolites fingerprint of the cells cultured under 3D was significantly different from that of ECs maintained under 2D. Moreover, the pattern of phosphometabolites was affected by coculture with C6-glioma cells and upon treatment with valproic acid, which is under clinical investigation as an antioangiogenic anticancer drug. The major effects were modulation of (i) energy metabolism intermediates such as phosphocreatine, (ii) precursors of phospholipids such as phosphomonoesters, and (iii) degradation products of phospholipids such as glycerophosphocholine. This endothelial model will be usefull as an enabling platform technology for tissue engineering.
Collapse
Affiliation(s)
- M Sterin
- Department of Pharmacology and Experimental Therapeutics, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | | | | | | |
Collapse
|
20
|
Kihara Y, Yanagida K, Masago K, Kita Y, Hishikawa D, Shindou H, Ishii S, Shimizu T. Platelet-activating factor production in the spinal cord of experimental allergic encephalomyelitis mice via the group IVA cytosolic phospholipase A2-lyso-PAFAT axis. THE JOURNAL OF IMMUNOLOGY 2008; 181:5008-14. [PMID: 18802104 DOI: 10.4049/jimmunol.181.7.5008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) plays a critical role in inflammatory disorders including experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis (MS). Although PAF accumulation in the spinal cord (SC) of EAE mice and cerebrospinal fluid of MS patients has been reported, little is known about the metabolic processing of PAF in these diseases. In this study, we demonstrate that the activities of phospholipase A(2) (PLA(2)) and acetyl-CoA:lyso-PAF acetyltransferase (LysoPAFAT) are elevated in the SC of EAE mice on a C57BL/6 genetic background compared with those of naive mice and correlate with disease severity. Correspondingly, levels of groups IVA, IVB, and IVF cytosolic PLA(2)s, group V secretory PLA(2), and LysoPAFAT transcripts are up-regulated in the SC of EAE mice. PAF acetylhydrolase activity is unchanged during the disease course. In addition, we show that LysoPAFAT mRNA and protein are predominantly expressed in microglia. Considering the substrate specificity and involvement of PAF production, group IVA cytosolic PLA(2) is likely to be responsible for the increased PLA(2) activity. These data suggest that PAF accumulation in the SC of EAE mice is profoundly dependent on the group IVA cytosolic PLA(2)/LysoPAFAT axis present in the infiltrating macrophages and activated microglia.
Collapse
Affiliation(s)
- Yasuyuki Kihara
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Differential expression of secretory phospholipases A2 in normal and malignant prostate cell lines: regulation by cytokines, cell signaling pathways, and epigenetic mechanisms. Neoplasia 2008; 10:279-86. [PMID: 18320072 DOI: 10.1593/neo.07965] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 01/07/2008] [Accepted: 01/10/2008] [Indexed: 12/31/2022]
Abstract
Upregulation of group IIA phospholipase A(2) (sPLA(2)-IIA) correlates with prostate tumor progression suggesting prooncogenic properties of this protein. Here, we report data on expression of three different sPLA(2) isozymes (groups IIA, V, and X) in normal (PrEC) and malignant (DU-145, PC-3, and LNCaP) human prostate cell lines. All studied cell lines constitutively expressed sPLA(2)-X, whereas sPLA(2)-V transcripts were identified only in malignant cells. In contrast, no expression of sPLA(2)-IIA was found in PrEC and DU-145 cells, but it was constitutively expressed by IFN-gamma in LNCaP and PC-3 cells. Expression of sPLA(2)-IIA is upregulated in PC-3 and in PrEC cell in a signal transducer and activator of transcription-1-dependent manner, but not in LNCaP cell. Additional signaling pathways regulating sPLA(2)-IIA expression include cAMP/protein kinase A, p38 mitogen-activated protein kinase, protein kinase C, Rho-kinase, and mitogen-activated/extracellular response protein kinase / extracellular signal-regulated kinase. No deletions were revealed in the sPLA(2)-IIA gene from DU-145 cells lacking the expression of sPLA(2)-IIA. Reexpression of sPLA(2)-IIA was induced by 5-aza-2'-deoxycytidine demonstrating that DNA methylation is implicated in the regulation of sPLA(2)-II. Together, these data suggest that sPLA(2)-IIA and sPLA(2)-V, but not sPLA(2)-X, are differentially expressed in normal and malignant prostate cells under the control of proinflammatory cytokines; epigenetic mechanisms appear involved in the regulation of sPLA(2)-IIA expression, at least in DU-145 cells.
Collapse
|
22
|
Schleicher M, Shepherd BR, Suarez Y, Fernandez-Hernando C, Yu J, Pan Y, Acevedo LM, Shadel GS, Sessa WC. Prohibitin-1 maintains the angiogenic capacity of endothelial cells by regulating mitochondrial function and senescence. J Cell Biol 2008; 180:101-12. [PMID: 18195103 PMCID: PMC2213620 DOI: 10.1083/jcb.200706072] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Accepted: 12/10/2007] [Indexed: 12/21/2022] Open
Abstract
Prohibitin 1 (PHB1) is a highly conserved protein that is mainly localized to the inner mitochondrial membrane and has been implicated in regulating mitochondrial function in yeast. Because mitochondria are emerging as an important regulator of vascular homeostasis, we examined PHB1 function in endothelial cells. PHB1 is highly expressed in the vascular system and knockdown of PHB1 in endothelial cells increases mitochondrial production of reactive oxygen species via inhibition of complex I, which results in cellular senescence. As a direct consequence, both Akt and Rac1 are hyperactivated, leading to cytoskeletal rearrangements and decreased endothelial cell motility, e.g., migration and tube formation. This is also reflected in an in vivo angiogenesis assay, where silencing of PHB1 blocks the formation of functional blood vessels. Collectively, our results provide evidence that PHB1 is important for mitochondrial function and prevents reactive oxygen species-induced senescence and thereby maintains the angiogenic capacity of endothelial cells.
Collapse
Affiliation(s)
- Michael Schleicher
- Department of Pharmacology, and Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06536, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Tosaki T, Sakamoto H, Kitahara J, Imai H, Nakagawa Y. Enhancement of Acetyl-CoA: 1- O-Alkyl-2-lyso- sn-glycero-3-phosphocholine Acetyltransferase Activity by Hydrogen Peroxide. Biol Pharm Bull 2007; 30:272-8. [PMID: 17268064 DOI: 10.1248/bpb.30.272] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The synthesis of platelet-activating factor (PAF) by human umbilical vein endothelial cell (HUVEC) in response to H2O2 was significantly increased in a concentration-dependent manner. When HUVEC were pretreated with diethyl maleate, which depletes intracellular glutathione, PAF synthesis was enhanced 3-fold upon 5 mM H2O2-treatment. Intracellular redox was involved in regulating PAF synthesis, since the addition of antioxidants such as N-acetylcysteine, pyrrolidinecarbodithioic acid (PDTC), and Trolox reduced PAF production in H2O2-treated HUVEC. The activity of acetyl-CoA: 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine acetyltransferase, which is involved in the last step of PAF synthesis, was also activated in H2O2-treated cells. However, exogenous lyso-PAF addition had not effected to acetyltransferase activity. The acetyltransferase activity responded quickly to H2O2-treatment, but the activation was transitory. A tyrosine kinase inhibitor and a calmodulin antagonist blocked acetyltransferase activity in H2O2-stimulated cells, suggesting that tyrosine kinase and calcium/calmodulin-dependent protein kinase are involved in regulating acetyltransferase activity. These observations suggest that H2O2 is one of the modulators of lyso-PAF acetyltransferase activity via a phosphorylation system and platelet-activating factor (PAF) synthesis.
Collapse
Affiliation(s)
- Takaki Tosaki
- School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | | | | | | | | |
Collapse
|
24
|
Marchand C, Favier J, Sirois MG. Role of MSK1 in the signaling pathway leading to VEGF-mediated PAF synthesis in endothelial cells. J Cell Biochem 2006; 98:1095-105. [PMID: 16479592 DOI: 10.1002/jcb.20840] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Vascular endothelial growth factor (VEGF) inflammatory effects require acute platelet-activating factor (PAF) synthesis by endothelial cells (EC). We previously reported that VEGF-mediated PAF synthesis involves the activation of VEGF receptor-2/Neuropilin-1 complex, which is leading to the activation of p38 and p42/44 mitogen-activated protein kinases (MAPKs) and group V secretory phospholipase A(2) (sPLA(2)-V). As the mechanisms regulating sPLA(2)-V remain unknown, we addressed the role of the mitogen- and stress-activated protein kinase-1 (MSK1), which can be rapidly and transiently activated by p38 or p42/44 MAPKs. In native bovine aortic endothelial cells (BAEC), we observed a constitutive protein interaction of MSK1 with p38, p42/44 MAPKs, and sPLA(2)-V. These protein interactions were maintained in BAEC transfected either with the empty vector pCDNA3.1, wild-type MSK1 (MSK1-WT) or N-terminal dead kinase MSK1 mutant (MSK1-D195A). However, in BAEC expressing C-terminal dead kinase MSK1 mutant (MSK1-D565A), the interaction between MSK1 and sPLA(2)-V was reduced by 82% and 90% under basal and VEGF-treated conditions as compared to native BAEC. Treatment with VEGF for 15 min increased basal PAF synthesis in native BAEC, pCDNA3.1, MSK1-WT, and MSK1-D195A by 166%, 139%, 125%, and 82%, respectively. In contrast, PAF synthesis was prevented in cells expressing MSK1-D565A mutant. These results demonstrate the essential role of the C-terminal domain of MSK1 for its constitutive interaction with sPLA(2)-V, which appears essential to support VEGF-mediated PAF synthesis.
Collapse
Affiliation(s)
- Catherine Marchand
- Research Center, Montreal Heart Institute, Université de Montréal, 5000 Belanger Street, Montreal, Quebec, Canada
| | | | | |
Collapse
|
25
|
Bacha AB, Gargouri Y, Bezzine S, Mejdoub H. Purification and biochemical characterization of phospholipase A2 from dromedary pancreas. Biochim Biophys Acta Gen Subj 2006; 1760:1202-9. [PMID: 16733083 DOI: 10.1016/j.bbagen.2006.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 03/09/2006] [Accepted: 03/13/2006] [Indexed: 11/16/2022]
Abstract
Dromedary pancreatic PLA2 (DrPLA2) was purified from delipidated pancreases. Pure protein was obtained after heat and acidic treatment (70 degrees C; pH 3.0), precipitation by ammonium sulphate and ethanol respectively, followed by sequential column chromatographies on Sephadex G-50, MonoS Sepharose, MonoQ Sepharose and C-8 reverse phase high pressure liquid chromatography. Purified DrPLA2, which is not glycosylated protein, was found to be monomeric protein with a molecular mass of 13748.55 Da. A specific activity of 600 U/mg for purified DrPLA2 was measured at optimal conditions (pH 8.0 and 37 degrees C) in the presence of 3 mM NaTDC and 7 mM CaCl(2) using PC as substrate. The sequence of the first fourteen amino-acid residues at the N-terminal extremity of DrPLA2 was determined by automatic Edman degradation. One single sequence was obtained and shows a close similarity with all other known pancreatic secreted phospholipases A2.
Collapse
Affiliation(s)
- Abir Ben Bacha
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS route de Soukra, 3038 Sfax, Tunisia
| | | | | | | |
Collapse
|
26
|
Maliba R, Lapointe S, Neagoe PE, Brkovic A, Sirois MG. Angiopoietins-1 and -2 are both capable of mediating endothelial PAF synthesis: intracellular signalling pathways. Cell Signal 2006; 18:1947-57. [PMID: 16617006 DOI: 10.1016/j.cellsig.2006.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 02/27/2006] [Accepted: 02/28/2006] [Indexed: 10/24/2022]
Abstract
Vascular endothelial growth factor (VEGF) is the only angiogenic growth factor capable of inducing an inflammatory response and we have recently demonstrated that its inflammatory effect is mediated by the endothelial synthesis of platelet-activating factor (PAF). Recently discovered, Ang1 and Ang2, upon binding to Tie2 receptor, modulate vascular permeability and integrity, contributing to angiogenesis. Ang1 was initially identified as a Tie2 agonist whereas Ang2 can behave as a context-dependent Tie2 agonist or antagonist. We sought to determine if Ang1 and/or Ang2 could modulate PAF synthesis in bovine aortic endothelial cells (BAEC) and if so, through which intracellular signalling pathways. Herein, we report that Ang1 and Ang2 (1 nM) are both capable of mediating a rapid Tie2 phosphorylation and a rapid, progressive and sustained endothelial PAF synthesis maximal within 4 h (1695% and 851% increase, respectively). Angiopoietin-mediated endothelial PAF synthesis requires the activation of the p38 and p42/44 MAPKs, PI3K intracellular signalling pathways, and a secreted phospholipase A(2) (sPLA(2)-V). Furthermore, angiopoietin-mediated PAF synthesis is partly driven by a relocalization of endogenous VEGF to the cell surface membrane. Our results demonstrate that the angiopoietins constitute another class of angiogenic factors capable of mediating PAF synthesis which may contribute to proinflammatory activities.
Collapse
Affiliation(s)
- Ricardo Maliba
- Montreal Heart Institute and Department of Pharmacology, Université de Montréal, 5000 Belanger Street, Montreal, Quebec, Canada
| | | | | | | | | |
Collapse
|
27
|
Barthomeuf C, Lamy S, Blanchette M, Boivin D, Gingras D, Béliveau R. Inhibition of sphingosine-1-phosphate- and vascular endothelial growth factor-induced endothelial cell chemotaxis by red grape skin polyphenols correlates with a decrease in early platelet-activating factor synthesis. Free Radic Biol Med 2006; 40:581-90. [PMID: 16458188 DOI: 10.1016/j.freeradbiomed.2005.09.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 08/25/2005] [Accepted: 09/09/2005] [Indexed: 11/20/2022]
Abstract
Vascular endothelial growth factor (VEGF) and platelet-derived lipid sphingosine-1-phosphate (S1P) are two proinflammatory mediators which contribute to angiogenesis, in part through the synthesis of platelet-activating factor (PAF). The red grape skin polyphenolic extract (SGE) both prevents and inhibits angiogenesis in the Matrigel model, decreases the basal motility of endothelial and cancer cells, and reverses the chemotactic effect of S1P and VEGF on bovine aortic endothelial cells (BAECs) as well as the chemotactic effect of conditioned medium on human HT-1080 fibrosarcoma, human U-87 glioblastoma, and human DAOY medulloblastoma cells. Inhibition of VEGF- and S1P-mediated chemotaxis by SGE is associated with a down-regulation of ERK and p38/MAPK phosphorylation and a decreased in acute PAF synthesis. Notably, as do extracellular inhibitors of PAF receptor, SGE prevents S1P-induced PAF synthesis and the resulting activation of the S1P/endothelial differentiation gene-1 cascade. Given the key role of VEGF and S1P in inflammation, angiogenesis, and tumor invasion, SGE may therefore contribute to prevent (or to delay) the development of diseases associated with angiogenesis dysregulation, including cancer. The dual inhibition of S1P- and VEGF-mediated migration of endothelial cell and of serum-stimulated migration of U-87 cells suggests a usefulness of SGE against highly invasive human glioblastoma.
Collapse
Affiliation(s)
- Chantal Barthomeuf
- INSERM U-484, Laboratoire de Pharmacognosie et Biotechnologies, Université d'Auvergne, Faculté de Pharmacie, Place H. Dunant, 63001 Clermont-Fd, France.
| | | | | | | | | | | |
Collapse
|
28
|
Villarrubia VG, Costa LA, Díez RA. [Secreted phospholipases A2 (sPLA2): friends or foes? Are they actors in antibacterial and anti-HIV resistance?]. Med Clin (Barc) 2005; 123:749-57. [PMID: 15574291 DOI: 10.1016/s0025-7753(04)74656-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this paper the authors update on the deletereous or beneficial roles of human and animal secretory phospholipases A2 (sPLA2). Although human sPLA2-IIA (inflammatory) was initially thought as a foe because its pathogenic implication in sepsis, multiorganic failure or other related syndromes, recent data indicates its role in in the antiinfectious host resistance. Thus, sPLA2-IIA exhibits potent bactericidal activities against gram-negative and gram-positive (in this case, together with other endogenous inflammatory factors) bacteria. Surprisingly, human sPLA-IIA does not show in vitro anti-human immunodeficiency virus (HIV) activity, whilst several sPLA2-IA isolated from bee and serpent venons do it: this is the case for crotoxin, a sPLA2-IA isolated from the venon of Crotalus durissus terrificus (sPLA2-Cdt). The mechanism for the in vitro anti-HIV activity of sPLA2-Cdt (inhibition of Gag p24) appears to be related to the ability of the drug to desestabilize ancorage (heparans) and fusion (cholesterol) receptors on HIV target cells.
Collapse
|
29
|
Neagoe PE, Lemieux C, Sirois MG. Vascular endothelial growth factor (VEGF)-A165-induced prostacyclin synthesis requires the activation of VEGF receptor-1 and -2 heterodimer. J Biol Chem 2005; 280:9904-12. [PMID: 15637071 DOI: 10.1074/jbc.m412017200] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We previously reported that vascular endothelial growth factor (VEGF)-A(165) inflammatory effect is mediated by acute platelet-activating factor synthesis from endothelial cells upon the activation of VEGF receptor-2 (VEGFR-2) and its coreceptor, neuropilin-1 (NRP-1). In addition, VEGF-A(165) promotes the release of other endothelial mediators including nitric oxide and prostacyclin (PGI(2)). However, it is unknown whether VEGF-A(165) is mediating PGI(2) synthesis through VEGF receptor-1 (VEGFR-1) and/or VEGF receptor-2 (VEGFR-2) activation and whether the coreceptor NRP-1 potentiates VEGF-A(165) activity. In this study, PGI(2) synthesis in bovine aortic endothelial cells (BAEC) was assessed by quantifying its stable metabolite (6-keto prostaglandin F(1alpha), 6-keto PGF(1alpha)) by enzyme-linked immunosorbent assay. Treatment of BAEC with VEGF analogs, VEGF-A(165) (VEGFR-1, VEGFR-2 and NRP-1 agonist) and VEGF-A(121) (VEGFR-1 and VEGFR-2 agonist) (up to 10(-9) m), increased PGI(2) synthesis by 70- and 40-fold within 15 min. Treatment with VEGFR-1 (placental growth factor and VEGF-B) or VEGFR-2 (VEGF-C) agonist did not increase PGI(2) synthesis. The combination of VEGFR-1 and VEGFR-2 agonists did not increase PGI(2) release. Pretreatment with a VEGFR-2 inhibitor abrogated PGI(2) release mediated by VEGF-A(165) and VEGF-A(121), and pretreatment of BAEC with antisense oligomers targeting VEGFR-1 or VEGFR-2 mRNA reduced PGI(2) synthesis mediated by VEGF-A(165) and VEGF-A(121) up to 79%. In summary, our data demonstrate that the activation of VEGFR-1 and VEGFR-2 heterodimer (VEGFR-1/R-2) is essential for PGI(2) synthesis mediated by VEGF-A(165) and VEGF-A(121), which cannot be reproduced by the parallel activation of VEGFR-1 and VEGFR-2 homodimers with corresponding agonists. In addition, the binding of VEGF-A(165) to NRP-1 potentiates its capacity to promote PGI(2) synthesis.
Collapse
Affiliation(s)
- Paul-Eduard Neagoe
- Research Center, Montreal Heart Institute, Department of Pharmacology, Université de Montréal, 5000 Belanger St., Montreal, Quebec H1T 1C8, Canada
| | | | | |
Collapse
|
30
|
Hite RD, Seeds MC, Safta AM, Jacinto RB, Gyves JI, Bass DA, Waite BM. Lysophospholipid generation and phosphatidylglycerol depletion in phospholipase A(2)-mediated surfactant dysfunction. Am J Physiol Lung Cell Mol Physiol 2004; 288:L618-24. [PMID: 15516491 DOI: 10.1152/ajplung.00274.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant's complex mixture of phospholipids and proteins reduces the work of breathing by lowering alveolar surface tension during respiration. One mechanism of surfactant damage appears to be the hydrolysis of phospholipid by phospholipases activated in the inflamed lung. Humans have several candidate secretory phospholipase A(2) (sPLA(2)) enzymes in lung cells and infiltrating leukocytes that could damage extracellular surfactant. We considered two mechanisms of surfactant disruption by five human sPLA(2)s, including generation of lysophospholipids and the depletion of specific phospholipids. All five sPLA(2)s studied ultimately caused surfactant dysfunction. Each enzyme exhibited a different pattern of hydrolysis of surfactant phospholipids. Phosphatidylcholine, the major phospholipid in surfactant and the greatest potential source for generation of lysophospholipids, was susceptible to hydrolysis by group IB, group V, and group X sPLA(2)s, but not group IIA or IID. Group IIA hydrolyzed both phosphatidylethanolamine and phosphatidylglycerol, whereas group IID was active against only phosphatidylglycerol. Thus, with groups IB and X, the generation of lysophospholipids corresponded with surfactant dysfunction. However, hydrolysis of and depletion of phosphatidylglycerol had a greater correlation with surfactant dysfunction for groups IIA and IID. Surfactant dysfunction caused by group V sPLA(2) is less clear and may be the combined result of both mechanisms.
Collapse
Affiliation(s)
- R Duncan Hite
- Section of Pulmonary Medicine, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1054, USA.
| | | | | | | | | | | | | |
Collapse
|
31
|
Lemieux C, Maliba R, Favier J, Théorêt JF, Merhi Y, Sirois MG. Angiopoietins can directly activate endothelial cells and neutrophils to promote proinflammatory responses. Blood 2004; 105:1523-30. [PMID: 15498854 DOI: 10.1182/blood-2004-09-3531] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Angiopoietin-1 (Ang1) and -2 (Ang2) are endothelial growth factors that bind to the tyrosine kinase receptor Tie2 and contribute to orchestrate blood vessel formation during angiogenesis. Ang1 mediates vessel maturation and integrity by the recruitment of pericytes. In contrast, Ang2 is classically considered as a Tie2 antagonist, counteracting the stabilizing action of Ang1. Inflammation exists in a mutually dependent association with angiogenesis and we have therefore studied the capacity of angiopoietins to modulate proinflammatory activities, namely P-selectin translocation and neutrophil adhesion onto endothelial cells. We observed that both Ang1 and Ang2 increased these biologic activities. Furthermore, combination of Ang1/Ang2 induced an additive effect on neutrophil adhesion but not on P-selectin translocation. In an attempt to clarify this phenomenon, we found that angiopoietins can directly activate neutrophils through Tie2 signaling as well as modulate platelet-activating factor (PAF) synthesis and beta(2) integrin functional up-regulation. Together, our data demonstrate that angiopoietins could promote acute recruitment of leukocytes, which might contribute to facilitate vascular remodeling and angiogenesis.
Collapse
Affiliation(s)
- Caroline Lemieux
- Research Center, Montreal Heart Institute, Montreal, QC, Canada H1T 1C8
| | | | | | | | | | | |
Collapse
|
32
|
Ito M, Ishikawa Y, Kiguchi H, Komiyama K, Murakami M, Kudo I, Akasaka Y, Ishii T. Distribution of type V secretory phospholipase A2 expression in human hepatocytes damaged by liver disease. J Gastroenterol Hepatol 2004; 19:1140-9. [PMID: 15377291 DOI: 10.1111/j.1440-1746.2004.03435.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND AIM Type V secretory phospholipase A2 (sPLA2-V) is a key enzyme in the arachidonate cascade. However, the distribution of sPLA2-V in human liver has not yet been investigated. In this study, the significance of sPLA2-V expression in human hepatocytes damaged by liver disease was investigated. METHODS Samples of liver tissue from patients with chronic hepatitis B and C, hepatitis virus-related liver cirrhosis, and congestive hepatocyte injury were immunostained with antibodies against sPLA2-V, cyclooxygenase (COX)-2, hepatitis viral antigens, transforming growth factor (TGF)-beta1, interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. RESULTS In chronic hepatitis patients, sPLA2-V-positive hepatocytes were scattered in the liver lobules, while cyclooxygenase-2, IL-1beta, and TNF-alpha were diffusely expressed. Hepatocytes around necroinflammatory lesions were strongly positive for sPLA2-V. Some sPLA2-V-positive hepatocytes were also positive for viral antigens. TGF-beta1 was expressed only in fibrotic lesions. The pattern of distribution of these proteins in liver cirrhosis patients was similar to that in chronic hepatitis patients, but sPLA2-V expression tended to be more intense than in chronic hepatitis. In the congestive liver, sPLA2-V, COX-2, and the two cytokines were diffusely expressed in surviving hepatocytes. CONCLUSIONS sPLA2-V expression in hepatocytes is induced by viral infection, fibrosis, and circulatory disturbance. Immunostaining using sPLA2-V antibody is useful for the detection of injured hepatocytes in patients with liver diseases.
Collapse
Affiliation(s)
- Masamichi Ito
- Department of Pathology, Toho University School of Medicine, Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Rollin S, Lemieux C, Maliba R, Favier J, Villeneuve LR, Allen BG, Soker S, Bazan NG, Merhi Y, Sirois MG. VEGF-mediated endothelial P-selectin translocation: role of VEGF receptors and endogenous PAF synthesis. Blood 2004; 103:3789-97. [PMID: 14764537 DOI: 10.1182/blood-2003-07-2272] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The acute increase in vascular permeability produced by vascular endothelial growth factor (VEGF-A(165)) requires activation of endothelial Flk-1 receptors (VEGFR-2) and stimulation of platelet-activating factor (PAF) synthesis. Like PAF, VEGF-A(165) promotes translocation of P-selectin to the endothelial cell (EC) surface. However, the mechanisms involved remain unknown. By treating human umbilical vein endothelial cells (HUVECs) with VEGF analogs, we show that activation of VEGFR-1 or VEGFR-2 or both induced a rapid and transient translocation of endothelial P-selectin and neutrophil adhesion to activated ECs. The effects mediated by VEGF-A(165) and VEGF-A(121) (VEGFR-1/VEGFR-2 agonists) were blocked by a selective VEGFR-2 inhibitor, SU1498. VEGF-A(165) was twice as potent as VEGF-A(121), which can be explained by the binding capacity of VEGF-A(165) to its coreceptor neuropilin-1 (NRP-1). Indeed, treatment with NRP-1 antagonist (GST-Ex7) reduced the effect of VEGF-A(165) to the levels observed upon stimulation with VEGF-A(121). Finally, the use of selective PAF receptor antagonists reduced VEGF-A(165)-mediated P-selectin translocation. Together, these data show that maximal P-selectin translocation and subsequent neutrophil adhesion was mediated by VEGF-A(165) on the activation of VEGFR-2/NRP-1 complex and required PAF synthesis.
Collapse
Affiliation(s)
- Simon Rollin
- Department of Pharmacology, University of Montreal, Montreal, QC, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Bernatchez PN, Tremblay F, Rollin S, Neagoe PE, Sirois MG. Sphingosine 1-phosphate effect on endothelial cell PAF synthesis: Role in cellular migration. J Cell Biochem 2003; 90:719-31. [PMID: 14587028 DOI: 10.1002/jcb.10686] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Sphingosine 1-phosphate (S1P) and vascular endothelial growth factor (VEGF) are two inflammatory mediators capable of promoting endothelial cell (EC) migration and angiogenesis. As VEGF inflammatory effect is mediated by the synthesis of endothelial platelet-activating factor (PAF) which is also contributing to VEGF chemotactic activity, we wanted to assess if S1P can trigger PAF synthesis in EC and if S1P-induced migration is PAF-dependent. Treatment of bovine aortic EC (BAEC) with S1P (10(-10)-10(-6) M) increased dose- and time-dependently the synthesis of PAF by up to 3.3-fold above the basal level, with a maximal amount of PAF detected at 20 min post-stimulation. This biological response was attenuated by inhibiting p38 mitogen-activated protein kinase (MAPK), cytosolic or secreted phospholipase A(2) (cPLA(2), sPLA(2)) activity, suggesting that p38 MAPK activation by S1P promotes the conversion of membrane phospholipids into PAF through the combined activation of cPLA(2) and sPLA(2). Interestingly, pretreatment of BAEC with extracellular PAF receptor antagonists (BN52021, 10(-5) M and CV3988, 10(-6) M) reduced by up to 42% the cellular migration induced by S1P (10(-6) M). These data demonstrate the capacity of S1P to induce PAF synthesis, which contributes in part to S1P chemotactic activity.
Collapse
Affiliation(s)
- Pascal N Bernatchez
- Montreal Heart Institute and Department of Pharmacology, University of Montreal, Montreal, Quebec, Canada
| | | | | | | | | |
Collapse
|
35
|
Gélinas DS, Bernatchez PN, Rollin S, Bazan NG, Sirois MG. Immediate and delayed VEGF-mediated NO synthesis in endothelial cells: role of PI3K, PKC and PLC pathways. Br J Pharmacol 2002; 137:1021-30. [PMID: 12429574 PMCID: PMC1573579 DOI: 10.1038/sj.bjp.0704956] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The mechanism(s) by which vascular endothelial growth factor (VEGF) induces endothelial nitric oxide synthase (eNOS) activation remain(s) unclear up to a certain extent. Therefore, we sought to evaluate the contribution of numerous pathways in VEGF-induced nitric oxide (NO) synthesis by measuring cGMP production. In addition, as VEGF induces the synthesis of NO and platelet-activating factor (PAF), we wanted to assess if the induction of PAF and NO is contributing to the synthesis of each other. 2. Herein, we show that a treatment of endothelial cells with a phospholipase C (PLC) inhibitor (U73122), a calmodulin antagonist (W-7) or with intracellular calcium chelators (EGTA/AM, BAPTA/AM) prevented VEGF-mediated eNOS Ser(1177)-phosphorylation and NO synthesis measured by cGMP production. 3. Pretreatment with phosphatidylinositol 3-kinase (PI3K) (Wortmannin, LY294002) or protein kinase C (PKC) (GF109203X, Ro318220) inhibitors attenuated eNOS Ser(1177)-phosphorylation mediated by VEGF, but did not alter immediate (0-10 min) cGMP synthesis induced by VEGF, but abrogated by up to 84% the delayed (10-30 min) cGMP synthesis. 4. Pretreatment with PAF synthesis inhibitors or with PAF receptor antagonists did not abrogate neither eNOS Ser(1177)-phosphorylation nor cGMP synthesis mediated by VEGF. 5. In conclusion, VEGF induces an immediate cGMP synthesis through the PLC-Ca2+/CaM pathway, and that the induction of delayed cGMP synthesis implies Akt and PKC activity.
Collapse
Affiliation(s)
- David S Gélinas
- Research Center, Montreal Heart Institute, and Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
| | - Pascal N Bernatchez
- Research Center, Montreal Heart Institute, and Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
| | - Simon Rollin
- Research Center, Montreal Heart Institute, and Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
| | - Nicolas G Bazan
- Neuroscience Center, LSU Health Sciences Center, New Orleans, Louisiana, LA 70112, USA
| | - Martin G Sirois
- Research Center, Montreal Heart Institute, and Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
- Author for correspondence:
| |
Collapse
|
36
|
Compernolle V, Brusselmans K, Acker T, Hoet P, Tjwa M, Beck H, Plaisance S, Dor Y, Keshet E, Lupu F, Nemery B, Dewerchin M, Van Veldhoven P, Plate K, Moons L, Collen D, Carmeliet P. Loss of HIF-2alpha and inhibition of VEGF impair fetal lung maturation, whereas treatment with VEGF prevents fatal respiratory distress in premature mice. Nat Med 2002; 8:702-10. [PMID: 12053176 DOI: 10.1038/nm721] [Citation(s) in RCA: 403] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Respiratory distress syndrome (RDS) due to insufficient production of surfactant is a common and severe complication of preterm delivery. Here, we report that loss of the hypoxia-inducible transcription factor-2alpha (HIF-2alpha) caused fatal RDS in neonatal mice due to insufficient surfactant production by alveolar type 2 cells. VEGF, a target of HIF-2alpha, regulates fetal lung maturation: because VEGF levels in alveolar cells were reduced in HIF-2alpha-deficient fetuses; mice with a deficiency of the VEGF(164) and VEGF(188) isoforms or of the HIF-binding site in the VEGF promotor died of RDS; intrauterine delivery of anti-VEGF-receptor-2 antibodies caused RDS and VEGF stimulated production of surfactant proteins by cultured type 2 pneumocytes. Intrauterine delivery or postnatal intratracheal instillation of VEGF stimulated conversion of glycogen to surfactant and protected preterm mice against RDS. The pneumotrophic effect of VEGF may have therapeutic potential for lung maturation in preterm infants.
Collapse
Affiliation(s)
- Veerle Compernolle
- The Center for Transgene Technology and Gene Therapy, Flanders Interuniversity, Institute for Biotechnology, Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Bernatchez PN, Allen BG, Gélinas DS, Guillemette G, Sirois MG. Regulation of VEGF-induced endothelial cell PAF synthesis: role of p42/44 MAPK, p38 MAPK and PI3K pathways. Br J Pharmacol 2001; 134:1253-62. [PMID: 11704645 PMCID: PMC1573057 DOI: 10.1038/sj.bjp.0704367] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Vascular endothelial growth factor (VEGF) is a potent angiogenic and inflammatory mediator. We have recently shown that this latter effect requires the activation of Flk-1 receptor and subsequent endothelial cell (EC) PAF synthesis. However, the intracellular events that regulate EC PAF synthesis upon Flk-1 stimulation by VEGF remain to be elucidated. 2. Using specific inhibitors and Western blot analysis, we herein report that in bovine aortic endothelial cells (BAEC), VEGF induces the synthesis of PAF through the cascade activation of Flk-1 receptor, phospholipase Cgamma (PLCgamma), protein kinase C (PKC) and p42/44 mitogen-activated protein kinases (MAPK). 3. Moreover, we demonstrate that VEGF-mediated PAF synthesis requires the activation of p38 MAPK, likely by directing the conversion of lyso-PAF to PAF. 4. Interestingly, we observed that VEGF also promoted the activation of the phosphatidyl inositol-3-phosphate kinase (PI3K) pathway, and that its blockade potentiated PAF synthesis following a VEGF treatment. Consequently, it appears that the PI3K pathway acts as a negative regulator of EC PAF synthesis. 5. Taken together, these results allow a better understanding of the intracellular events activated upon EC stimulation by VEGF, and shed a new light on the mechanisms by which VEGF induces PAF synthesis.
Collapse
Affiliation(s)
- Pascal N Bernatchez
- Research Center, Montreal Heart Institute, Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
| | - Bruce G Allen
- Department of Biochemistry, University of Montreal, Montreal (Qc), Canada
| | - David S Gélinas
- Research Center, Montreal Heart Institute, Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
| | - Gaétan Guillemette
- Department of Pharmacology, University of Sherbrooke, Sherbrooke (Qc), Canada
| | - Martin G Sirois
- Research Center, Montreal Heart Institute, Department of Pharmacology, University of Montreal, Montreal (Qc), Canada
- Author for correspondence:
| |
Collapse
|