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Murakami M. Extracellular vesicles as a hydrolytic platform of secreted phospholipase A 2. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159536. [PMID: 39032626 DOI: 10.1016/j.bbalip.2024.159536] [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: 05/31/2024] [Revised: 07/04/2024] [Accepted: 07/17/2024] [Indexed: 07/23/2024]
Abstract
Extracellular vesicles (EVs) represent small vesicles secreted from cells, including exosomes (40-150 nm in diameter), which are released via the multivesicular endosomal pathway, and microvesicles and ectosomes (100-1000 nm), which are produced by plasma membrane budding. Broadly, EVs also include vesicles generated from dying cells, such as apoptotic bodies (5-10 μm), as well as exomeres (< 50 nm), which are very small, non-membranous nanoparticles. EVs play important roles in cell-to-cell signaling in various aspects of cancer, immunity, metabolism, and so on by transferring proteins, microRNAs (miRNAs), and metabolites as cargos from donor cells to recipient cells. Although lipids are one of the major components of EVs, they have long been recognized as merely the "wall" that partitions the lumen of the vesicle from the outside. However, it has recently become obvious that lipid composition of EVs influences their properties and functions, that EVs act as a carrier of a variety of lipid mediators, and that lipid mediators are produced in EV membranes by the hydrolytic action of secreted phospholipase A2s (sPLA2s). In this article, we will make an overview of the roles of lipids in EVs, with a particular focus on sPLA2-driven mobilization of lipid mediators from EVs and its biological significance.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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2
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Compartmentalized regulation of lipid signaling in oxidative stress and inflammation: Plasmalogens, oxidized lipids and ferroptosis as new paradigms of bioactive lipid research. Prog Lipid Res 2023; 89:101207. [PMID: 36464139 DOI: 10.1016/j.plipres.2022.101207] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 12/03/2022]
Abstract
Perturbations in lipid homeostasis combined with conditions favoring oxidative stress constitute a hallmark of the inflammatory response. In this review we focus on the most recent results concerning lipid signaling in various oxidative stress-mediated responses and inflammation. These include phagocytosis and ferroptosis. The best characterized event, common to these responses, is the synthesis of oxygenated metabolites of arachidonic acid and other polyunsaturated fatty acids. Major developments in this area have highlighted the importance of compartmentalization of the enzymes and lipid substrates in shaping the appropriate response. In parallel, other relevant lipid metabolic pathways are also activated and, until recently, there has been a general lack of knowledge on the enzyme regulation and molecular mechanisms operating in these pathways. Specifically, data accumulated in recent years on the regulation and biological significance of plasmalogens and oxidized phospholipids have expanded our knowledge on the involvement of lipid metabolism in the progression of disease and the return to homeostasis. These recent major developments have helped to establish the concept of membrane phospholipids as cellular repositories for the compartmentalized production of bioactive lipids involved in cellular regulation. Importantly, an enzyme classically described as being involved in regulating the homeostatic turnover of phospholipids, namely the group VIA Ca2+-independent phospholipase A2 (iPLA2β), has taken center stage in oxidative stress and inflammation research owing to its key involvement in regulating metabolic and ferroptotic signals arising from membrane phospholipids. Understanding the role of iPLA2β in ferroptosis and metabolism not only broadens our knowledge of disease but also opens possible new horizons for this enzyme as a target for therapeutic intervention.
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3
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Lipid Droplets, Phospholipase A 2, Arachidonic Acid, and Atherosclerosis. Biomedicines 2021; 9:biomedicines9121891. [PMID: 34944707 PMCID: PMC8699036 DOI: 10.3390/biomedicines9121891] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/01/2021] [Accepted: 12/10/2021] [Indexed: 02/07/2023] Open
Abstract
Lipid droplets, classically regarded as static storage organelles, are currently considered as dynamic structures involved in key processes of lipid metabolism, cellular homeostasis and signaling. Studies on the inflammatory state of atherosclerotic plaques suggest that circulating monocytes interact with products released by endothelial cells and may acquire a foamy phenotype before crossing the endothelial barrier and differentiating into macrophages. One such compound released in significant amounts into the bloodstream is arachidonic acid, the common precursor of eicosanoids, and a potent inducer of neutral lipid synthesis and lipid droplet formation in circulating monocytes. Members of the family of phospholipase A2, which hydrolyze the fatty acid present at the sn-2 position of phospholipids, have recently emerged as key controllers of lipid droplet homeostasis, regulating their formation and the availability of fatty acids for lipid mediator production. In this paper we discuss recent findings related to lipid droplet dynamics in immune cells and the ways these organelles are involved in regulating arachidonic acid availability and metabolism in the context of atherosclerosis.
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Dabral D, van den Bogaart G. The Roles of Phospholipase A 2 in Phagocytes. Front Cell Dev Biol 2021; 9:673502. [PMID: 34179001 PMCID: PMC8222813 DOI: 10.3389/fcell.2021.673502] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/11/2021] [Indexed: 12/21/2022] Open
Abstract
Phagocytic cells, such as macrophages, neutrophils, and dendritic cells, ingest particles larger than about 0.5 μM and thereby clear microbial pathogens and malignant cells from the body. These phagocytic cargoes are proteolytically degraded within the lumen of phagosomes, and peptides derived from them are presented on Major Histocompatibility Complexes (MHC) for the activation of T cells. Mammalian PLA2 isozymes belong to a large family of enzymes that cleave phospholipids at the second position of the glycerol backbone, releasing a free fatty acid and a lysolipid moiety. In human macrophages, at least 15 different PLA2 forms are expressed, and expression of many of these is dependent on pathogenic stimulation. Intriguing questions are why so many PLA2 forms are expressed in macrophages, and what are the functional consequences of their altered gene expression after encountering pathogenic stimuli. In this review, we discuss the evidence of the differential roles of different forms of PLA2 in phagocytic immune cells. These roles include: lipid signaling for immune cell activation, initial phagocytic particle uptake, microbial action for the killing and degradation of ingested microbes, and the repair of membranes induced by oxygen radicals. We also discuss the roles of PLA2 in the subsequent digestion of ingested phagocytic cargoes for antigen presentation to T cells.
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Affiliation(s)
- Deepti Dabral
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Geert van den Bogaart
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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Murphy RC, Altemeier WA, Lai Y, Hallstrand TS. The Intricate Web of Phospholipase A 2s and Specific Features of Airway Hyperresponsiveness in Asthma. Am J Respir Cell Mol Biol 2020; 63:543-545. [PMID: 32484733 DOI: 10.1165/rcmb.2020-0131le] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
| | | | - Ying Lai
- University of Washington, Seattle, Washington
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6
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Rodríguez JP, Leiguez E, Guijas C, Lomonte B, Gutiérrez JM, Teixeira C, Balboa MA, Balsinde J. A Lipidomic Perspective of the Action of Group IIA Secreted Phospholipase A 2 on Human Monocytes: Lipid Droplet Biogenesis and Activation of Cytosolic Phospholipase A 2α. Biomolecules 2020; 10:biom10060891. [PMID: 32532115 PMCID: PMC7355433 DOI: 10.3390/biom10060891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 12/14/2022] Open
Abstract
Phospholipase A2s constitute a wide group of lipid-modifying enzymes which display a variety of functions in innate immune responses. In this work, we utilized mass spectrometry-based lipidomic approaches to investigate the action of Asp-49 Ca2+-dependent secreted phospholipase A2 (sPLA2) (MT-III) and Lys-49 sPLA2 (MT-II), two group IIA phospholipase A2s isolated from the venom of the snake Bothrops asper, on human peripheral blood monocytes. MT-III is catalytically active, whereas MT-II lacks enzyme activity. A large decrease in the fatty acid content of membrane phospholipids was detected in MT III-treated monocytes. The significant diminution of the cellular content of phospholipid-bound arachidonic acid seemed to be mediated, in part, by the activation of the endogenous group IVA cytosolic phospholipase A2α. MT-III triggered the formation of triacylglycerol and cholesterol enriched in palmitic, stearic, and oleic acids, but not arachidonic acid, along with an increase in lipid droplet synthesis. Additionally, it was shown that the increased availability of arachidonic acid arising from phospholipid hydrolysis promoted abundant eicosanoid synthesis. The inactive form, MT-II, failed to produce any of the effects described above. These studies provide a complete lipidomic characterization of the monocyte response to snake venom group IIA phospholipase A2, and reveal significant connections among lipid droplet biogenesis, cell signaling and biochemical pathways that contribute to initiating the inflammatory response.
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Affiliation(s)
- Juan P. Rodríguez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (J.P.R.); (E.L.); (C.G.); (M.A.B.)
- Laboratorio de Investigaciones Bioquímicas de la Facultad de Medicina (LIBIM), Instituto de Química Básica y Aplicada del Nordeste Argentino (IQUIBA-NEA), Universidad Nacional del Nordeste, Consejo Nacional de Investigaciones Científicas y Técnicas (UNNE-CONICET), Corrientes 3400, Argentina
| | - Elbio Leiguez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (J.P.R.); (E.L.); (C.G.); (M.A.B.)
- Laboratorio de Farmacologia, Instituto Butantan, Sao Paulo 01000, Brazil;
| | - Carlos Guijas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (J.P.R.); (E.L.); (C.G.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501–2060, Costa Rica; (B.L.); (J.M.G.)
| | - José M. Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501–2060, Costa Rica; (B.L.); (J.M.G.)
| | - Catarina Teixeira
- Laboratorio de Farmacologia, Instituto Butantan, Sao Paulo 01000, Brazil;
| | - María A. Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (J.P.R.); (E.L.); (C.G.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (J.P.R.); (E.L.); (C.G.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-983-423-062
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Monge P, Garrido A, Rubio JM, Magrioti V, Kokotos G, Balboa MA, Balsinde J. The Contribution of Cytosolic Group IVA and Calcium-Independent Group VIA Phospholipase A 2s to Adrenic Acid Mobilization in Murine Macrophages. Biomolecules 2020; 10:biom10040542. [PMID: 32260121 PMCID: PMC7226511 DOI: 10.3390/biom10040542] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 12/11/2022] Open
Abstract
Adrenic acid (AA), the 2-carbon elongation product of arachidonic acid, is present at significant levels in membrane phospholipids of mouse peritoneal macrophages. Despite its abundance and structural similarity to arachidonic acid, very little is known about the molecular mechanisms governing adrenic acid mobilization in cells of the innate immune system. This contrasts with the wide availability of data on arachidonic acid mobilization. In this work, we used mass-spectrometry-based lipidomic procedures to define the profiles of macrophage phospholipids that contain adrenic acid and their behavior during receptor activation. We identified the phospholipid sources from which adrenic acid is mobilized, and compared the data with arachidonic acid mobilization. Taking advantage of the use of selective inhibitors, we also showed that cytosolic group IVA phospholipase A2 is involved in the release of both adrenic and arachidonic acids. Importantly, calcium independent group VIA phospholipase A2 spared arachidonate-containing phospholipids and hydrolyzed only those that contain adrenic acid. These results identify separate mechanisms for regulating the utilization of adrenic and arachidonic acids, and suggest that the two fatty acids may serve non-redundant functions in cells.
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Affiliation(s)
- Patricia Monge
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (P.M.); (A.G.); (J.M.R.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Alvaro Garrido
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (P.M.); (A.G.); (J.M.R.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Julio M. Rubio
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (P.M.); (A.G.); (J.M.R.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Victoria Magrioti
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece; (V.M.); (G.K.)
| | - George Kokotos
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece; (V.M.); (G.K.)
| | - María A. Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (P.M.); (A.G.); (J.M.R.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain; (P.M.); (A.G.); (J.M.R.); (M.A.B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-983-423-062
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Degradation of group V secretory phospholipase A 2 in lung endothelium is mediated by autophagy. Microvasc Res 2019; 129:103954. [PMID: 31730773 DOI: 10.1016/j.mvr.2019.103954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 09/18/2019] [Accepted: 11/10/2019] [Indexed: 02/07/2023]
Abstract
Group V secretory phospholipase A2 (gVPLA2) is a potent inflammatory mediator in mammalian tissues that hydrolyzes phospholipids and initiates eicosanoid biosynthesis. Previous work has demonstrated that multiple inflammatory stimuli induce its expression and secretion in several cell types, including the lung endothelium. However, little is known about the mechanism(s) by which gVPLA2 inflammatory signaling is subsequently downregulated. Therefore, in this study we characterized potential clearance mechanisms for gVPLA2 in lung endothelial cells (EC). We observed that exogenous gVPLA2 is taken up rapidly by nutrient-starved human pulmonary artery EC (HPAEC) in vitro, and its cellular expression subsequently is reduced over several hours. In parallel experiments performed in pulmonary vascular EC isolated from mice genetically deficient in gVPLA2, the degradation of exogenously applied gVPLA2 occurs in a qualitatively similar fashion. This degradation is significantly attenuated in EC treated with ammonium chloride or chloroquine, which are lysosomal inhibitors that block autophagic flux. In contrast, the proteasomal inhibitor MG132 fails to prevent the clearance of gVPLA2. Both immunofluorescence microscopy and proximity ligation assay demonstrate the co-localization of LC3 and gVPLA2 during this process, indicating the association of gVPLA2 with autophagosomes. Nutrient starvation, a known inducer of autophagy, is sufficient to stimulate gVPLA2 degradation. These results suggest that a lysosome-mediated autophagy pathway contributes to gVPLA2 clearance from lung EC. These novel observations advance our understanding of the mechanism by which this key inflammatory enzyme is downregulated in the lung vasculature.
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Guijas C, Bermúdez MA, Meana C, Astudillo AM, Pereira L, Fernández-Caballero L, Balboa MA, Balsinde J. Neutral Lipids Are Not a Source of Arachidonic Acid for Lipid Mediator Signaling in Human Foamy Monocytes. Cells 2019; 8:cells8080941. [PMID: 31434356 PMCID: PMC6721759 DOI: 10.3390/cells8080941] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 12/13/2022] Open
Abstract
Human monocytes exposed to free arachidonic acid (AA), a secretory product of endothelial cells, acquire a foamy phenotype which is due to the accumulation of cytoplasmic lipid droplets with high AA content. Recruitment of foamy monocytes to the inflamed endothelium contributes to the development of atherosclerotic lesions. In this work, we investigated the potential role of AA stored in the neutral lipids of foamy monocytes to be cleaved by lipases and contribute to lipid mediator signaling. To this end, we used mass spectrometry-based lipidomic approaches combined with strategies to generate monocytes with different concentrations of AA. Results from our experiments indicate that the phospholipid AA pool in monocytes is stable and does not change upon exposure of the cells to the external AA. On the contrary, the AA pool in triacylglycerol is expandable and can accommodate relatively large amounts of fatty acid. Stimulation of the cells with opsonized zymosan results in the expected decreases of cellular AA. Under all conditions examined, all of the AA decreases observed in stimulated cells were accounted for by decreases in the phospholipid pool; we failed to detect any contribution of the triacylglycerol pool to the response. Experiments utilizing selective inhibitors of phospholipid or triacylglyerol hydrolysis confirmed that the phospholipid pool is the sole contributor of the AA liberated by stimulated cells. Thus, the AA in the triacylglycerol is not a source of free AA for the lipid mediator signaling during stimulation of human foamy monocytes and may be used for other cellular functions.
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Affiliation(s)
- Carlos Guijas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Miguel A Bermúdez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
| | - Clara Meana
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Alma M Astudillo
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Laura Pereira
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
| | - Lidia Fernández-Caballero
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
| | - María A Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
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Šribar J, Kovačič L, Oberčkal J, Ivanušec A, Petan T, Fox JW, Križaj I. The neurotoxic secreted phospholipase A 2 from the Vipera a. ammodytes venom targets cytochrome c oxidase in neuronal mitochondria. Sci Rep 2019; 9:283. [PMID: 30670719 PMCID: PMC6342964 DOI: 10.1038/s41598-018-36461-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 11/16/2018] [Indexed: 12/30/2022] Open
Abstract
The β-neurotoxic secreted phospholipases A2 (sPLA2s) block neuro-muscular transmission by poisoning nerve terminals. Damage inflicted by such sPLA2s (β-ntx) on neuronal mitochondria is characteristic, very similar to that induced by structurally homologous endogenous group IIA sPLA2 when its activity is elevated, as, for example, in the early phase of Alzheimer's disease. Using ammodytoxin (Atx), the β-ntx from the venom of the nose-horned viper (Vipera a. ammodytes), the sPLA2 receptor R25 has been detected in neuronal mitochondria. This receptor has been purified from porcine cerebral cortex mitochondria by a new Atx-affinity-based chromatographic procedure. Mass spectrometry analysis revealed R25 to be the subunit II of cytochrome c oxidase (CCOX), an essential constituent of the respiratory chain complex. CCOX was confirmed as being the first intracellular membrane receptor for sPLA2 by alternative Atx-affinity-labellings of purified CCOX, supported also by the encounter of Atx and CCOX in PC12 cells. This discovery suggests the explanation of the mechanism by which β-ntx hinders production of ATP in poisoned nerve endings. It also provides a new insight into the potential function and dysfunction of endogenous GIIA sPLA2 in mitochondria.
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Affiliation(s)
- Jernej Šribar
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Lidija Kovačič
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Jernej Oberčkal
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Adrijan Ivanušec
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Jay W Fox
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
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Nolin JD, Murphy RC, Gelb MH, Altemeier WA, Henderson WR, Hallstrand TS. Function of secreted phospholipase A 2 group-X in asthma and allergic disease. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:827-837. [PMID: 30529275 DOI: 10.1016/j.bbalip.2018.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 12/11/2022]
Abstract
Elevated secreted phospholipase A2 (sPLA2) activity in the airways has been implicated in the pathogenesis of asthma and allergic disease for some time. The identity and function of these enzymes in asthma is becoming clear from work in our lab and others. We focused on sPLA2 group X (sPLA2-X) after identifying increased levels of this enzyme in asthma, and that it is responsible for a large portion of sPLA2 activity in the airways and that the levels are strongly associated with features of airway hyperresponsiveness (AHR). In this review, we discuss studies that implicated sPLA2-X in human asthma, and murine models that demonstrate a critical role of this enzyme as a regulator of type-2 inflammation, AHR and production of eicosanoids. We discuss the mechanism by which sPLA2-X acts to regulate eicosanoids in leukocytes, as well as effects that are mediated through the generation of lysophospholipids and through receptor-mediated functions. This article is part of a Special Issue entitled Novel functions of phospholipase A2 Guest Editors: Makoto Murakami and Gerard Lambeau.
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Affiliation(s)
- James D Nolin
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep, University of Washington, Seattle, WA, United States of America
| | - Ryan C Murphy
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep, University of Washington, Seattle, WA, United States of America
| | - Michael H Gelb
- Department of Chemistry, University of Washington, Seattle, WA, United States of America; Department of Biochemistry, University of Washington, Seattle, WA, United States of America
| | - William A Altemeier
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep, University of Washington, Seattle, WA, United States of America
| | - William R Henderson
- Division of Allergy and Infectious DIseases, University of Washington, Seattle, WA, United States of America
| | - Teal S Hallstrand
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep, University of Washington, Seattle, WA, United States of America.
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Phospholipase A 2 catalysis and lipid mediator lipidomics. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:766-771. [PMID: 30905345 DOI: 10.1016/j.bbalip.2018.08.010] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/10/2018] [Accepted: 08/16/2018] [Indexed: 01/09/2023]
Abstract
Phospholipase A2 (PLA2) enzymes are the upstream regulators of the eicosanoid pathway liberating free arachidonic acid from the sn-2 position of membrane phospholipids. Free intracellular arachidonic acid serves as a substrate for the eicosanoid biosynthetic enzymes including cyclooxygenases, lipoxygenases, and cytochrome P450s that lead to inflammation. The Group IVA cytosolic (cPLA2), Group VIA calcium-independent (iPLA2), and Group V secreted (sPLA2) are three well-characterized human enzymes that have been implicated in eicosanoid formation. In this review, we will introduce and summarize the regulation of catalytic activity and cellular localization, structural characteristics, interfacial activation and kinetics, substrate specificity, inhibitor binding and interactions, and the downstream implications for eicosanoid biosynthesis of these three important PLA2 enzymes.
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13
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Selectivity of phospholipid hydrolysis by phospholipase A 2 enzymes in activated cells leading to polyunsaturated fatty acid mobilization. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:772-783. [PMID: 30010011 DOI: 10.1016/j.bbalip.2018.07.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/08/2018] [Accepted: 07/10/2018] [Indexed: 12/14/2022]
Abstract
Phospholipase A2s are enzymes that hydrolyze the fatty acid at the sn-2 position of the glycerol backbone of membrane glycerophospholipids. Given the asymmetric distribution of fatty acids within phospholipids, where saturated fatty acids tend to be present at the sn-1 position, and polyunsaturated fatty acids such as those of the omega-3 and omega-6 series overwhelmingly localize in the sn-2 position, the phospholipase A2 reaction is of utmost importance as a regulatory checkpoint for the mobilization of these fatty acids and the subsequent synthesis of proinflammatory omega-6-derived eicosanoids on one hand, and omega-3-derived specialized pro-resolving mediators on the other. The great variety of phospholipase A2s, their differential substrate selectivity under a variety of pathophysiological conditions, as well as the different compartmentalization of each enzyme and accessibility to substrate, render this class of enzymes also key to membrane phospholipid remodeling reactions, and the generation of specific lipid mediators not related with canonical metabolites of omega-6 or omega-3 fatty acids. This review highlights novel findings regarding the selective hydrolysis of phospholipids by phospholipase A2s and the influence this may have on the ability of these enzymes to generate distinct lipid mediators with essential functions in biological processes. This brings a new understanding of the cellular roles of these enzymes depending upon activation conditions.
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14
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Astudillo AM, Meana C, Guijas C, Pereira L, Lebrero P, Balboa MA, Balsinde J. Occurrence and biological activity of palmitoleic acid isomers in phagocytic cells. J Lipid Res 2017; 59:237-249. [PMID: 29167413 DOI: 10.1194/jlr.m079145] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 11/10/2017] [Indexed: 12/28/2022] Open
Abstract
Recent studies have highlighted the role of palmitoleic acid [16:1n-7 (cis-9-hexadecenoic acid)] as a lipid hormone that coordinates cross-talk between liver and adipose tissue and exerts anti-inflammatory protective effects on hepatic steatosis and insulin signaling in murine models of metabolic disease. More recently, a 16:1n-7 isomer, cis-7-hexadecenoic acid (16:1n-9), that also possesses marked anti-inflammatory effects, has been described in human circulating monocytes and monocyte-derived macrophages. By using gas chromatographic/mass spectrometric analyses of dimethyl disulfide derivatives of fatty acyl methyl esters, we describe in this study the presence of a third 16:1 isomer, sapienic acid [16:1n-10 (6-cis-hexadecenoic acid)], in phagocytic cells. Cellular levels of 16:1n-10 appear to depend not only on the cellular content of linoleic acid, but also on the expression level of fatty acid desaturase 2, thus revealing a complex regulation both at the enzyme level, via fatty acid substrate competition, and directly at the gene level. However, unlike 16:1n-7 and 16:1n-9, 16:1n-10 levels are not regulated by the activation state of the cell. Moreover, while 16:1n-7 and 16:1n-9 manifest strong anti-inflammatory activity when added to the cells at low concentrations (10 μM), notably higher concentrations of 16:1n-10 are required to observe a comparable effect. Collectively, these results suggest the presence in phagocytic cells of an unexpected variety of 16:1 isomers, which can be distinguished on the basis of their biological activity and cellular regulation.
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Affiliation(s)
- Alma M Astudillo
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Clara Meana
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Carlos Guijas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
| | - Laura Pereira
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain
| | - Patricia Lebrero
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - María A Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, 47003 Valladolid, Spain .,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
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15
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Karray A, Bou Ali M, Kharrat N, Gargouri Y, Bezzine S. Antibacterial, antifungal and anticoagulant activities of chicken PLA2 group V expressed in Pichia pastoris. Int J Biol Macromol 2017; 108:127-134. [PMID: 29129630 DOI: 10.1016/j.ijbiomac.2017.11.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 11/07/2017] [Accepted: 11/08/2017] [Indexed: 02/02/2023]
Abstract
Secretory class V phospholipase A2 (PLA2-V) has been shown to be involved in inflammatory processes in cellular studies, but the biochemical and physical properties of this important enzyme have been unclear. As a first step towards understanding the structure, function and regulation of this PLA2, we report the expression and characterization of PLA2-V from chicken (ChPLA2-V). The ChPLA2-V cDNA was synthesized from chicken heart polyA mRNA by RT-PCR, and an expression construct containing the PLA2 was established. After expression in Pichia pastoris cells, the active enzyme was purified. The purified ChPLA2-V protein was biochemically and physiologically characterized. The recombinant ChPLA2-V has an absolute requirement for Ca2+ for enzymatic activity. The optimum pH for this enzyme is pH 8.5 in Tris-HCl buffer with phosphatidylcholine as substrate. ChPLA2-V was found to display potent Gram-positive and Gram-negative bactericidal activity and antifungal activity in vitro. The purified enzyme ChPLA2-V with much stronger anticoagulant activity compared with the intestinal and pancreatic chicken PLA2-V was approximately 10 times more active. Chicken group V PLA2, like mammal one, may be considered as a future therapeutic agents against fungal and bacterial infections and as an anticoagulant agent.
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Affiliation(s)
- Aida Karray
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS Route de Soukra, université de Sfax, Tunisia
| | - Madiha Bou Ali
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS Route de Soukra, université de Sfax, Tunisia
| | - Nedia Kharrat
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS Route de Soukra, université de Sfax, Tunisia
| | - Youssef Gargouri
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS Route de Soukra, université de Sfax, Tunisia
| | - Sofiane Bezzine
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS Route de Soukra, université de Sfax, Tunisia.
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16
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Gil-de-Gómez L, Astudillo AM, Lebrero P, Balboa MA, Balsinde J. Essential Role for Ethanolamine Plasmalogen Hydrolysis in Bacterial Lipopolysaccharide Priming of Macrophages for Enhanced Arachidonic Acid Release. Front Immunol 2017; 8:1251. [PMID: 29033952 PMCID: PMC5626835 DOI: 10.3389/fimmu.2017.01251] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/20/2017] [Indexed: 12/16/2022] Open
Abstract
Due to their high content in esterified arachidonic acid (AA), macrophages provide large amounts of eicosanoids during innate immune reactions. Bacterial lipopolysaccharide (LPS) is a poor trigger of AA mobilization in macrophages but does have the capacity to prime these cells for greatly increased AA release upon subsequent stimulation. In this work, we have studied molecular mechanisms underlying this phenomenon. By using mass spectrometry-based lipidomic analyses, we show in this work that LPS-primed zymosan-stimulated macrophages exhibit an elevated consumption of a particular phospholipid species, i.e., the ethanolamine plasmalogens, which results from reduced remodeling of phospholipids via coenzyme A-independent transacylation reactions. Importantly however, LPS-primed macrophages show no changes in their capacity to directly incorporate AA into phospholipids via CoA-dependent acylation reactions. The essential role for ethanolamine plasmalogen hydrolysis in LPS priming is further demonstrated by the use of plasmalogen-deficient cells. These cells, while responding normally to zymosan by releasing quantities of AA similar to those released by cells expressing normal plasmalogen levels under the same conditions, fail to show an LPS-primed response to the same stimulus, thus unambiguously demonstrating a cause–effect relationship between LPS priming and plasmalogen hydrolysis. Collectively, these results suggest a hitherto unrecognized role for ethanolamine plasmalogen hydrolysis and CoA-independent transacylation reactions in modulating the eicosanoid biosynthetic response.
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Affiliation(s)
- Luis Gil-de-Gómez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, Valladolid, Spain
| | - Alma M Astudillo
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Patricia Lebrero
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - María A Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valladolid, Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
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17
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Nolin JD, Ogden HL, Lai Y, Altemeier WA, Frevert CW, Bollinger JG, Naika GS, Kicic A, Stick SM, Lambeau G, Henderson WR, Gelb MH, Hallstrand TS. Identification of Epithelial Phospholipase A 2 Receptor 1 as a Potential Target in Asthma. Am J Respir Cell Mol Biol 2017; 55:825-836. [PMID: 27448109 DOI: 10.1165/rcmb.2015-0150oc] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Secreted phospholipase A2s (sPLA2s) regulate eicosanoid formation and have been implicated in asthma. Although sPLA2s function as enzymes, some of the sPLA2s bind with high affinity to a C-type lectin receptor, called PLA2R1, which has functions in both cellular signaling and clearance of sPLA2s. We sought to examine the expression of PLA2R1 in the airway epithelium of human subjects with asthma and the function of the murine Pla2r1 gene in a model of asthma. Expression of PLA2R1 in epithelial brushings was assessed in two distinct cohorts of children with asthma by microarray and quantitative PCR, and immunostaining for PLA2R1 was conducted on endobronchial tissue and epithelial brushings from adults with asthma. C57BL/129 mice deficient in Pla2r1 (Pla2r1-/-) were characterized in an ovalbumin (OVA) model of allergic asthma. PLA2R1 was differentially overexpressed in epithelial brushings of children with atopic asthma in both cohorts. Immunostaining for PLA2R1 in endobronchial tissue localized to submucosal glandular epithelium and columnar epithelial cells. After OVA sensitization and challenge, Pla2r1-/- mice had increased airway hyperresponsiveness, as well as an increase in cellular trafficking of eosinophils to the peribronchial space and bronchoalveolar lavage fluid, and an increase in airway permeability. In addition, Pla2r1-/- mice had more dendritic cells in the lung, higher levels of OVA-specific IgG, and increased production of both type-1 and type-2 cytokines by lung leukocytes. PLA2R1 is increased in the airway epithelium in asthma, and serves as a regulator of airway hyperresponsiveness, airway permeability, antigen sensitization, and airway inflammation.
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Affiliation(s)
- James D Nolin
- From the 1 Division of Pulmonary and Critical Care and
| | - H Luke Ogden
- From the 1 Division of Pulmonary and Critical Care and
| | - Ying Lai
- From the 1 Division of Pulmonary and Critical Care and
| | | | - Charles W Frevert
- From the 1 Division of Pulmonary and Critical Care and.,2 Department of Comparative Medicine
| | | | | | - Anthony Kicic
- 4 The Telethon Kids Institute, Centre for Health Research, University of Western Australia, Nedlands, Western Australia, Australia.,5 Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.,6 School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia.,7 Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia; and
| | - Stephen M Stick
- 4 The Telethon Kids Institute, Centre for Health Research, University of Western Australia, Nedlands, Western Australia, Australia.,5 Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.,6 School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia.,7 Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia; and
| | - Gerard Lambeau
- 8 Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | | | - Michael H Gelb
- 3 Department of Chemistry, and.,10 Department of Biochemistry, University of Washington, Seattle, Washington
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18
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Dennis EA. Liberating Chiral Lipid Mediators, Inflammatory Enzymes, and LIPID MAPS from Biological Grease. J Biol Chem 2016; 291:24431-24448. [PMID: 27555328 DOI: 10.1074/jbc.x116.723791] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In 1970, it was well accepted that the central role of lipids was in energy storage and metabolism, and it was assumed that amphipathic lipids simply served a passive structural role as the backbone of biological membranes. As a result, the scientific community was focused on nucleic acids, proteins, and carbohydrates as information-containing molecules. It took considerable effort until scientists accepted that lipids also "encode" specific and unique biological information and play a central role in cell signaling. Along with this realization came the recognition that the enzymes that act on lipid substrates residing in or on membranes and micelles must also have important signaling roles, spurring curiosity into their potentially unique modes of action differing from those acting on water-soluble substrates. This led to the creation of the concept of "surface dilution kinetics" for describing the mechanism of enzymes acting on lipid substrates, as well as the demonstration that lipid enzymes such as phospholipase A2 (PLA2) contain allosteric activator sites for specific phospholipids as well as for membranes. As our understanding of phospholipases advanced, so did the understanding that many of the lipids released by these enzymes are chiral information-containing signaling molecules; for example, PLA2 regulates the generation of precursors for the biosynthesis of eicosanoids and other bioactive lipid mediators of inflammation and resolution underlying disease progression. The creation of the LIPID MAPS initiative in 2003 and the ensuing development of the lipidomics field have revealed that lipid metabolites are central to human metabolism. Today lipids are recognized as key mediators of health and disease as we enter a new era of biomarkers and personalized medicine. This article is my personal "reflection" on these scientific advances.
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Affiliation(s)
- Edward A Dennis
- From the Department of Chemistry and Biochemistry and Department of Pharmacology, School of Medicine, University of California at San Diego, La Jolla, California 92093-0601.
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19
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Endogenous secreted phospholipase A2 group X regulates cysteinyl leukotrienes synthesis by human eosinophils. J Allergy Clin Immunol 2015; 137:268-277.e8. [PMID: 26139511 DOI: 10.1016/j.jaci.2015.05.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 04/23/2015] [Accepted: 05/04/2015] [Indexed: 02/05/2023]
Abstract
BACKGROUND Phospholipase A2s mediate the rate-limiting step in the formation of eicosanoids such as cysteinyl leukotrienes (CysLTs). Group IVA cytosolic PLA2α (cPLA2α) is thought to be the dominant PLA2 in eosinophils; however, eosinophils also have secreted PLA2 (sPLA2) activity that has not been fully defined. OBJECTIVES To examine the expression of sPLA2 group X (sPLA2-X) in eosinophils, the participation of sPLA2-X in the formation of CysLTs, and the mechanism by which sPLA2-X initiates the synthesis of CysLTs in eosinophils. METHODS Peripheral blood eosinophils were obtained from volunteers with asthma and/or allergy. A rabbit polyclonal anti-sPLA2-X antibody identified sPLA2-X by Western blot. We used confocal microscopy to colocalize the sPLA2-X to intracellular structures. An inhibitor of sPLA2-X (ROC-0929) that does not inhibit other mammalian sPLA2s, as well as inhibitors of the mitogen-activated kinase cascade (MAPK) and cPLA2α, was used to examine the mechanism of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-mediated formation of CysLT. RESULTS Eosinophils express the mammalian sPLA2-X gene (PLA2G10). The sPLA2-X protein is located in the endoplasmic reticulum, golgi, and granules of eosinophils and moves to the granules and lipid bodies during fMLP-mediated activation. Selective sPLA2-X inhibition attenuated the fMLP-mediated release of arachidonic acid and CysLT formation by eosinophils. Inhibitors of p38, extracellular-signal-regulated kinases 1/2 (p44/42 MAPK), c-Jun N-terminal kinase, and cPLA2α also attenuated the fMLP-mediated formation of CysLT. The sPLA2-X inhibitor reduced the phosphorylation of p38 and extracellular-signal-regulated kinases 1/2 (p44/42 MAPK) as well as cPLA2α during cellular activation, indicating that sPLA2-X is involved in activating the MAPK cascade leading to the formation of CysLT via cPLA2α. We further demonstrate that sPLA2-X is activated before secretion from the cell during activation. Short-term priming with IL-13 and TNF/IL-1β increased the expression of PLA2G10 by eosinophils. CONCLUSIONS These results demonstrate that sPLA2-X plays a significant role in the formation of CysLTs by human eosinophils. The predominant role of the enzyme is the regulation of MAPK activation that leads to the phosphorylation of cPLA2α. The sPLA2-X protein is regulated by proteolytic cleavage, suggesting that an inflammatory environment may promote the formation of CysLTs through this mechanism. These results have important implications for the treatment of eosinophilic disorders such as asthma.
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20
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Oberčkal J, Kovačič L, Šribar J, Leonardi A, Dolinar K, Pucer Janež A, Križaj I. On the role of protein disulfide isomerase in the retrograde cell transport of secreted phospholipases A2. PLoS One 2015; 10:e0120692. [PMID: 25763817 PMCID: PMC4357439 DOI: 10.1371/journal.pone.0120692] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/25/2015] [Indexed: 11/29/2022] Open
Abstract
Following the finding that ammodytoxin (Atx), a neurotoxic secreted phospholipase A2 (sPLA2) in snake venom, binds specifically to protein disulfide isomerase (PDI) in vitro we show that these proteins also interact in living rat PC12 cells that are able to internalize this group IIA (GIIA) sPLA2. Atx and PDI co-localize in both differentiated and non-differentiated PC12 cells, as shown by fluorescence microscopy. Based on a model of the complex between Atx and yeast PDI (yPDI), a three-dimensional model of the complex between Atx and human PDI (hPDI) was constructed. The Atx binding site on hPDI is situated between domains b and b’. Atx interacts hPDI with an extensive area on its interfacial binding surface. The mammalian GIB, GIIA, GV and GX sPLA2s have the same fold as Atx. The first three sPLA2s have been detected intracellularly but not the last one. The models of their complexes with hPDI were constructed by replacement of Atx with the respective mammalian sPLA2 in the Atx—hPDI complex and molecular docking of the structures. According to the generated models, mammalian GIB, GIIA and GV sPLA2s form complexes with hPDI very similar to that with Atx. The contact area between GX sPLA2 and hPDI is however different from that of the other sPLA2s. Heterologous competition of Atx binding to hPDI with GV and GX sPLA2s confirmed the model-based expectation that GV sPLA2 was a more effective inhibitor than GX sPLA2, thus validating our model. The results suggest a role of hPDI in the (patho)physiology of some snake venom and mammalian sPLA2s by assisting the retrograde transport of these molecules from the cell surface. The sPLA2–hPDI model constitutes a valuable tool to facilitate further insights into this process and into the (patho)physiology of sPLA2s in relation to their action intracellularly.
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Affiliation(s)
- Jernej Oberčkal
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Lidija Kovačič
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Jernej Šribar
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Adrijana Leonardi
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Klemen Dolinar
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Anja Pucer Janež
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
- * E-mail:
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21
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Rubio JM, Rodríguez JP, Gil-de-Gómez L, Guijas C, Balboa MA, Balsinde J. Group V secreted phospholipase A2 is upregulated by IL-4 in human macrophages and mediates phagocytosis via hydrolysis of ethanolamine phospholipids. THE JOURNAL OF IMMUNOLOGY 2015; 194:3327-39. [PMID: 25725101 DOI: 10.4049/jimmunol.1401026] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Studies on the heterogeneity and plasticity of macrophage populations led to the identification of two major polarization states: classically activated macrophages or M1, induced by IFN-γ plus LPS, and alternatively activated macrophages, induced by IL-4. We studied the expression of multiple phospholipase A2 enzymes in human macrophages and the effect that polarization of the cells has on their levels. At least 11 phospholipase A2 genes were found at significant levels in human macrophages, as detected by quantitative PCR. None of these exhibited marked changes after treating the cells with IFN-γ plus LPS. However, macrophage treatment with IL-4 led to strong upregulation of the secreted group V phospholipase A2 (sPLA2-V), both at the mRNA and protein levels. In parallel with increasing sPLA2-V expression levels, IL-4-treated macrophages exhibited increased phagocytosis of yeast-derived zymosan and bacteria, and we show that both events are causally related, because cells deficient in sPLA2-V exhibited decreased phagocytosis, and cells overexpressing the enzyme manifested higher rates of phagocytosis. Mass spectrometry analyses of lipid changes in the IL-4-treated macrophages suggest that ethanolamine lysophospholipid (LPE) is an sPLA2-V-derived product that may be involved in regulating phagocytosis. Cellular levels of LPE are selectively maintained by sPLA2-V. By supplementing sPLA2-V-deficient cells with LPE, phagocytosis of zymosan or bacteria was fully restored in IL-4-treated cells. Collectively, our results show that sPLA2-V is required for efficient phagocytosis by IL-4-treated human macrophages and provide evidence that sPLA2-V-derived LPE is involved in the process.
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Affiliation(s)
- Julio M Rubio
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, 28029 Madrid, Spain; and
| | - Juan P Rodríguez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain; Laboratorio de Investigación en Proteínas, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, 3400 Corrientes, Argentina
| | - Luis Gil-de-Gómez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Carlos Guijas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, 28029 Madrid, Spain; and
| | - María A Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, 28029 Madrid, Spain; and
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, 47003 Valladolid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, 28029 Madrid, Spain; and
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22
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Abstract
The inflammatory response plays an important role in host defense and maintenance of homeostasis, while imbalances in these responses can also lead to pathologic disease processes. Emerging data show that RKIP interacts with multiple signaling molecules that may potentiate multiple functions during inflammatory processes. Here, we review the interaction of RKIP with both the MAPK and NF-κB pathways in relation to chronic inflammatory diseases. In these settings, it can both inhibit inflammatory pathways as well contribute to pro-inflammatory signaling, often depending on the interactions with multiple proteins and perhaps lipids. The interactions of RKIP with proteins, phospholipids, fatty acids, and their enzymes thus could play a substantial role in diseases like asthma and diabetes. Targeting interactions of RKIP with these pathways could lead to novel approaches to treatment.
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Affiliation(s)
- Jinming Zhao
- University of Pittsburgh Asthma Institute at UPMC/Pulmonary Allergy and Critical Care Medicine Division, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sally Wenzel
- University of Pittsburgh Asthma Institute at UPMC/Pulmonary Allergy and Critical Care Medicine Division, University of Pittsburgh, Pittsburgh, Pennsylvania
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RHEE HAEJIN, JI LITING, KIM SEUNGHYUK, LEE JONGHO. Human group V secretory phospholipase A2 is associated with lipid rafts and internalized in a flotillin-dependent pathway. Int J Mol Med 2013; 32:1126-36. [DOI: 10.3892/ijmm.2013.1492] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/23/2013] [Indexed: 11/06/2022] Open
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Rodríguez Diez G, Sánchez Campos S, Giusto N, Salvador G. Specific roles for Group V secretory PLA2 in retinal iron-induced oxidative stress. Implications for age-related macular degeneration. Exp Eye Res 2013; 113:172-81. [DOI: 10.1016/j.exer.2013.05.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/14/2013] [Accepted: 05/21/2013] [Indexed: 11/15/2022]
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Hallstrand TS, Lai Y, Altemeier WA, Appel CL, Johnson B, Frevert CW, Hudkins KL, Bollinger JG, Woodruff PG, Hyde DM, Henderson WR, Gelb MH. Regulation and function of epithelial secreted phospholipase A2 group X in asthma. Am J Respir Crit Care Med 2013; 188:42-50. [PMID: 23614662 PMCID: PMC3735246 DOI: 10.1164/rccm.201301-0084oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 04/08/2013] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Indirect airway hyperresponsiveness (AHR) is a fundamental feature of asthma that is manifest as exercise-induced bronchoconstriction (EIB). Secreted phospholipase A2 group X (sPLA2-X) plays a key role in regulating eicosanoid formation and the development of inflammation and AHR in murine models. OBJECTIVES We sought to examine sPLA2-X in the airway epithelium and airway wall of patients with asthma, the relationship to AHR in humans, and the regulation and function of sPLA2-X within the epithelium. METHODS We precisely phenotyped 34 patients with asthma (19 with and 15 without EIB) and 10 normal control subjects to examine in vivo differences in epithelial gene expression, quantitative morphometry of endobronchial biopsies, and levels of secreted protein. The regulation of sPLA2-X gene (PLA2G10) expression was examined in primary airway epithelial cell cultures. The function of epithelial sPLA2-X in eicosanoid formation was examined using PLA2 inhibitors and murine tracheal epithelial cells with Pla2g10 deletion. MEASUREMENTS AND MAIN RESULTS We found that sPLA2-X protein is increased in the airways of patients with asthma and that epithelial-derived sPLA2-X may be increased in association with indirect AHR. The expression of sPLA2-X increases during in vitro epithelial differentiation; is regulated by inflammatory signals including tumor necrosis factor, IL-13, and IL-17; and is both secreted from the epithelium and directly participates in the release of arachidonic acid by epithelial cells. CONCLUSIONS These data reveal a relationship between epithelial-derived sPLA2-X and indirect AHR in asthma and that sPLA2-X serves as an epithelial regulator of inflammatory eicosanoid formation. Therapies targeting epithelial sPLA2-X may be useful in asthma.
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Gil-de-Gómez L, Astudillo AM, Meana C, Rubio JM, Guijas C, Balboa MA, Balsinde J. A phosphatidylinositol species acutely generated by activated macrophages regulates innate immune responses. THE JOURNAL OF IMMUNOLOGY 2013; 190:5169-77. [PMID: 23567931 DOI: 10.4049/jimmunol.1203494] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Activation of macrophages with stimuli of the innate immune response results in the intense remodeling of arachidonate-containing phospholipids, leading to the mobilization of large quantities of this fatty acid for conversion into biologically active eicosanoids. As a consequence of this process, the arachidonate levels in membrane phospholipids markedly decrease. We have applied mass spectrometry-based lipid profiling to study the levels of arachidonate-containing phospholipids under inflammatory activation of macrophages. We identify an unusual inositol phospholipid molecule, PI(20:4/20:4), the levels of which do not decrease but actually increase by 300% after activation of the macrophages. PI(20:4/20:4) is formed and degraded rapidly, suggesting a role for this molecule in regulating cell signaling events. Using a metabolipidomic approach consisting in exposing the cells to deuterium-labeled arachidonate at the time they are exposed to stimuli, we show that PI(20:4/20:4) biosynthesis occurs via the sequential incorporation of arachidonate, first into the sn-2 position of a preformed phosphatidylinositol (PI) molecule, followed by the rapid introduction of a second arachidonate moiety into the sn-1 position. Generation requires the participation of cytosolic phospholipase A2α and CoA-dependent acyltransferases. PI(20:4/20:4) formation is also detected in vivo in murine peritonitis exudates. Elevating the intracellular concentration of PI(20:4/20:4) by introducing the lipid into the cells results in enhancement of the microbicidal capacity of macrophages, as measured by reactive oxygen metabolite production and lysozyme release. These findings suggest that PI(20:4/20:4) is a novel bioactive inositol phospholipid molecule that regulates innate immune responses in macrophages.
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Affiliation(s)
- Luis Gil-de-Gómez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, 47003 Valladolid, Spain
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Phospholipases of mineralization competent cells and matrix vesicles: roles in physiological and pathological mineralizations. Int J Mol Sci 2013; 14:5036-129. [PMID: 23455471 PMCID: PMC3634480 DOI: 10.3390/ijms14035036] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/24/2013] [Accepted: 01/25/2013] [Indexed: 02/08/2023] Open
Abstract
The present review aims to systematically and critically analyze the current knowledge on phospholipases and their role in physiological and pathological mineralization undertaken by mineralization competent cells. Cellular lipid metabolism plays an important role in biological mineralization. The physiological mechanisms of mineralization are likely to take place in tissues other than in bones and teeth under specific pathological conditions. For instance, vascular calcification in arteries of patients with renal failure, diabetes mellitus or atherosclerosis recapitulates the mechanisms of bone formation. Osteoporosis—a bone resorbing disease—and rheumatoid arthritis originating from the inflammation in the synovium are also affected by cellular lipid metabolism. The focus is on the lipid metabolism due to the effects of dietary lipids on bone health. These and other phenomena indicate that phospholipases may participate in bone remodelling as evidenced by their expression in smooth muscle cells, in bone forming osteoblasts, chondrocytes and in bone resorbing osteoclasts. Among various enzymes involved, phospholipases A1 or A2, phospholipase C, phospholipase D, autotaxin and sphingomyelinase are engaged in membrane lipid remodelling during early stages of mineralization and cell maturation in mineralization-competent cells. Numerous experimental evidences suggested that phospholipases exert their action at various stages of mineralization by affecting intracellular signaling and cell differentiation. The lipid metabolites—such as arachidonic acid, lysophospholipids, and sphingosine-1-phosphate are involved in cell signaling and inflammation reactions. Phospholipases are also important members of the cellular machinery engaged in matrix vesicle (MV) biogenesis and exocytosis. They may favour mineral formation inside MVs, may catalyse MV membrane breakdown necessary for the release of mineral deposits into extracellular matrix (ECM), or participate in hydrolysis of ECM. The biological functions of phospholipases are discussed from the perspective of animal and cellular knockout models, as well as disease implications, development of potent inhibitors and therapeutic interventions.
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Guijas C, Astudillo AM, Gil-de-Gómez L, Rubio JM, Balboa MA, Balsinde J. Phospholipid sources for adrenic acid mobilization in RAW 264.7 macrophages. Comparison with arachidonic acid. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1386-93. [PMID: 22824377 DOI: 10.1016/j.bbalip.2012.07.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/08/2012] [Accepted: 07/13/2012] [Indexed: 02/04/2023]
Abstract
Cells metabolize arachidonic acid (AA) to adrenic acid (AdA) via 2-carbon elongation reactions. Like AA, AdA can be converted into multiple oxygenated metabolites, with important roles in various physiological and pathophysiological processes. However, in contrast to AA, there is virtually no information on how the cells regulate the availability of free AdA for conversion into bioactive products. We have used a comparative lipidomic approach with both gas chromatography and liquid chromatography coupled to mass spectrometry to characterize changes in the levels of AA- and AdA-containing phospholipid species in RAW 264.7 macrophage-like cells. Incubation of the cells with AA results in an extensive conversion to AdA but both fatty acids do not compete with each other for esterification into phospholipids. AdA but not AA, shows preference for incorporation into phospholipids containing stearic acid at the sn-1 position. After stimulation of the cells with zymosan, both AA and AdA are released in large quantities, albeit AA is released to a greater extent. Finally, a variety of phosphatidylcholine and phosphatidylinositol molecular species contribute to AA; however, AdA is liberated exclusively from phosphatidylcholine species. Collectively, these results identify significant differences in the cellular utilization of AA and AdA by the macrophages, suggesting non-redundant biological actions for these two fatty acids.
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Affiliation(s)
- Carlos Guijas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain
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29
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Abstract
Phospholipids are present in all living organisms. They are a major component of all biological membranes, along with glycolipids and cholesterol. Enzymes aimed at cleaving the various bonds in phospholipids, namely phospholipases, are consequently widespread in nature, playing very diverse roles from aggression in snake venom to signal transduction, lipid mediators production, and digestion in humans. Although all phospholipases target phospholipids as substrates, they vary in the site of action on the phospholipids molecules, physiological function, mode of action, and their regulation. Significant studies on phospholipases characterization, physiological role, and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances, such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factors and major causes of pathophysiological effects. In this introductory chapter, we provide brief details of different phospholipases.
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Affiliation(s)
- Ahmed Aloulou
- National School of Engineers of Sfax, University of Sfax, Sfax, Tunisia.
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30
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Dynamics of arachidonic acid mobilization by inflammatory cells. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:249-56. [PMID: 22155285 DOI: 10.1016/j.bbalip.2011.11.006] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 11/19/2011] [Accepted: 11/21/2011] [Indexed: 01/06/2023]
Abstract
The development of mass spectrometry-based techniques is opening new insights into the understanding of arachidonic acid (AA) metabolism. AA incorporation, remodeling and release are collectively controlled by acyltransferases, phospholipases and transacylases that exquisitely regulate the distribution of AA between the different glycerophospholipid species and its mobilization during cellular stimulation. Traditionally, studies involving phospholipid AA metabolism were conducted by using radioactive precursors and scintillation counting from thin layer chromatography separations that provided only information about lipid classes. Today, the input of lipidomic approaches offers the possibility of characterizing and quantifying specific molecular species with great accuracy and within a biological context associated to protein and/or gene expression in a temporal frame. This review summarizes recent results applying mass spectrometry-based lipidomic approaches to the identification of AA-containing glycerophospholipids, phospholipid AA remodeling and synthesis of oxygenated metabolites.
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Degousee N, Kelvin DJ, Geisslinger G, Hwang DM, Stefanski E, Wang XH, Danesh A, Angioni C, Schmidt H, Lindsay TF, Gelb MH, Bollinger J, Payré C, Lambeau G, Arm JP, Keating A, Rubin BB. Group V phospholipase A2 in bone marrow-derived myeloid cells and bronchial epithelial cells promotes bacterial clearance after Escherichia coli pneumonia. J Biol Chem 2011; 286:35650-35662. [PMID: 21849511 PMCID: PMC3195628 DOI: 10.1074/jbc.m111.262733] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 08/11/2011] [Indexed: 02/05/2023] Open
Abstract
Group V-secreted phospholipase A(2) (GV sPLA(2)) hydrolyzes bacterial phospholipids and initiates eicosanoid biosynthesis. Here, we elucidate the role of GV sPLA(2) in the pathophysiology of Escherichia coli pneumonia. Inflammatory cells and bronchial epithelial cells both express GV sPLA(2) after pulmonary E. coli infection. GV(-/-) mice accumulate fewer polymorphonuclear leukocytes in alveoli, have higher levels of E. coli in bronchoalveolar lavage fluid and lung, and develop respiratory acidosis, more severe hypothermia, and higher IL-6, IL-10, and TNF-α levels than GV(+/+) mice after pulmonary E. coli infection. Eicosanoid levels in bronchoalveolar lavage are similar in GV(+/+) and GV(-/-) mice after lung E. coli infection. In contrast, GV(+/+) mice have higher levels of prostaglandin D(2) (PGD(2)), PGF(2α), and 15-keto-PGE(2) in lung and express higher levels of ICAM-1 and PECAM-1 on pulmonary endothelial cells than GV(-/-) mice after lung infection with E. coli. Selective deletion of GV sPLA(2) in non-myeloid cells impairs leukocyte accumulation after pulmonary E. coli infection, and lack of GV sPLA(2) in either bone marrow-derived myeloid cells or non-myeloid cells attenuates E. coli clearance from the alveolar space and the lung parenchyma. These observations show that GV sPLA(2) in bone marrow-derived myeloid cells as well as non-myeloid cells, which are likely bronchial epithelial cells, participate in the regulation of the innate immune response to pulmonary infection with E. coli.
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Affiliation(s)
- Norbert Degousee
- Division of Vascular Surgery, Peter Munk Cardiac Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - David J Kelvin
- Division of Experimental Therapeutics, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China
| | - Gerd Geisslinger
- Institut für Klinische Pharmakologie, D-60590, Frankfurt am Main, Germany
| | - David M Hwang
- Department of Pathology, Toronto General Hospital Research Institute of the University Health Network and the Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Eva Stefanski
- Division of Vascular Surgery, Peter Munk Cardiac Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Xing-Hua Wang
- Department of Medical Oncology and Hematology, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Ali Danesh
- Division of Experimental Therapeutics, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Carlo Angioni
- Institut für Klinische Pharmakologie, D-60590, Frankfurt am Main, Germany
| | - Helmut Schmidt
- Institut für Klinische Pharmakologie, D-60590, Frankfurt am Main, Germany
| | - Thomas F Lindsay
- Division of Vascular Surgery, Peter Munk Cardiac Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Michael H Gelb
- Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington 98195
| | - James Bollinger
- Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington 98195
| | - Christine Payré
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice, Sophia Antipolis et Centre National de la Recherche Scientifique, Sophia Antipolis, 06560 Valbonne, France
| | - Gérard Lambeau
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice, Sophia Antipolis et Centre National de la Recherche Scientifique, Sophia Antipolis, 06560 Valbonne, France
| | - Jonathan P Arm
- Division of Rheumatology, Immunology, and Allergy, and Partners Asthma Center, Brigham and Women's Hospital, Boston Massachusetts 02115
| | - Armand Keating
- Department of Medical Oncology and Hematology, University of Toronto, Toronto, Ontario M5G 2C4, Canada
| | - Barry B Rubin
- Division of Vascular Surgery, Peter Munk Cardiac Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada.
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Astudillo AM, Pérez-Chacón G, Meana C, Balgoma D, Pol A, Del Pozo MA, Balboa MA, Balsinde J. Altered arachidonate distribution in macrophages from caveolin-1 null mice leading to reduced eicosanoid synthesis. J Biol Chem 2011; 286:35299-307. [PMID: 21852231 DOI: 10.1074/jbc.m111.277137] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In this work we have studied the effect of caveolin-1 deficiency on the mechanisms that regulate free arachidonic acid (AA) availability. The results presented here demonstrate that macrophages from caveolin-1-deficient mice exhibit elevated fatty acid incorporation and remodeling and a constitutively increased CoA-independent transacylase activity. Mass spectrometry-based lipidomic analyses reveal stable alterations in the profile of AA distribution among phospholipids, manifested by reduced levels of AA in choline glycerophospholipids but elevated levels in ethanolamine glycerophospholipids and phosphatidylinositol. Furthermore, macrophages from caveolin-1 null mice show decreased AA mobilization and prostaglandin E(2) and LTB(4) production upon cell stimulation. Collectively, these results provide insight into the role of caveolin-1 in AA homeostasis and suggest an important role for this protein in the eicosanoid biosynthetic response.
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Affiliation(s)
- Alma M Astudillo
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, 47003 Valladolid, Spain
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15-Lipoxygenase 1 interacts with phosphatidylethanolamine-binding protein to regulate MAPK signaling in human airway epithelial cells. Proc Natl Acad Sci U S A 2011; 108:14246-51. [PMID: 21831839 DOI: 10.1073/pnas.1018075108] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Epithelial 15-lipoxygenase 1 (15LO1) and activated ERK are increased in asthma despite modest elevations in IL-13. MAPK kinase (MEK)/ERK activation is regulated by interactions of Raf-1 with phosphatidylethanolamine-binding protein 1 (PEBP1). Epithelial 15LO1 generates intracellular 15-hydroxyeicosatetraenoic acid (15HETE) conjugated to phosphatidylethanolamine (PE) (15HETE-PE). We hypothesized that (i) 15LO1 and its product 15HETE-PE serve as signaling molecules interacting with PEBP1 to activate Raf-1/MEK/ERK and that (ii) this 15LO1-15HETE-PE-regulated ERK activation amplifies IL-4Rα downstream pathways. Our results demonstrate that high epithelial 15LO1 levels correlate with ERK phosphorylation ex vivo. In vitro, IL-13 induces 15LO1, which preferentially binds to PEBP1, causing PEBP1 to dissociate from Raf-1 and activate ERK. Exogenous 15HETE-PE similarly induces dissociation of PEBP1 from Raf-1 independently of IL-13/15LO1. siRNA knockdown of 15LO1 decreases the dissociation of Raf-1 from PEBP1, and the resulting lower ERK activation leads to lower downstream IL-4Rα-related gene expression. Identical protein-protein interactions are observed in endobronchial biopsies and fresh epithelial cells from asthmatics ex vivo. Colocalization of Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma. Low 15LO1 levels in normals limit its colocalization with PEBP1. The results confirm a previously unknown signaling role for 15LO1 and its PE-conjugated eicosanoid product in human airway epithelial cells. This pathway enhances critical inflammatory pathways integral to asthma pathogenesis.
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Hallstrand TS, Lai Y, Ni Z, Oslund RC, Henderson WR, Gelb MH, Wenzel SE. Relationship between levels of secreted phospholipase A₂ groups IIA and X in the airways and asthma severity. Clin Exp Allergy 2011; 41:801-10. [PMID: 21255140 PMCID: PMC3093436 DOI: 10.1111/j.1365-2222.2010.03676.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background Secreted phospholipase A(2) (sPLA(2) ) may be important mediators of asthma, but the specific sPLA(2) s involved in asthma are not known. Objective To evaluate sPLA(2) group IIA, V, and X proteins (sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X) in bronchoalveolar lavage (BAL) fluid, BAL cells, and airway epithelial cells of subjects with and without asthma, and examine the relationship between the levels of specific sPLA(2) enzymes and airway inflammation, asthma severity, and lung function. Methods The expression of sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X in BAL cells and epithelial brushings was assessed by qPCR. The levels of these sPLA(2) proteins and sPLA(2) activity with and without group II and group X-specific inhibitors were measured in BAL fluid from 18 controls and 39 asthmatics. Results The airway epithelium expressed sPLA(2) -X at higher levels than either sPLA(2) -IIA or sPLA(2) -V, whereas BAL cells expressed sPLA(2) -IIA and sPLA(2) -X at similar levels. The majority of sPLA(2) activity in BAL fluid was attributed to either sPLA(2) -IIA or sPLA(2) -X. After 10-fold concentration of BAL fluid, the levels of sPLA(2) -X normalized to total protein were increased in asthma and were associated with lung function, the concentration of induced sputum neutrophils, and prostaglandin E(2) . The levels of sPLA(2) -IIA were elevated in asthma when normalized to total protein, but were not related to lung function, markers of airway inflammation or eicosanoid formation. Conclusions and Clinical Relevance These data indicate that sPLA(2) -IIA and sPLA(2) -X are the major sPLA(2) s in human airways, and suggest a link between the levels of sPLA(2) -X in the airways and several features of asthma.
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Affiliation(s)
- T S Hallstrand
- Department of Medicine, Divisions of Pulmonary and Critical Care, University of Washington, Seattle, WA 98195, USA.
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Valdearcos M, Esquinas E, Meana C, Gil-de-Gómez L, Guijas C, Balsinde J, Balboa MA. Subcellular localization and role of lipin-1 in human macrophages. THE JOURNAL OF IMMUNOLOGY 2011; 186:6004-13. [PMID: 21478406 DOI: 10.4049/jimmunol.1003279] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The lipins have been described as metabolic enzymes that regulate lipid biosynthesis and also signaling processes by controlling the cellular concentration of bioactive lipids, phosphatidic acid, and diacylgycerol. In the present work we have studied the subcellular localization and role of lipin-1 in human monocyte-derived macrophages. Human macrophages express lipin-1 isoforms α and β. A transfected lipin-1α-enhanced GFP construct associates with membranes of cellular organelles that can be stained with Nile Red. Colocalization experiments with lipid droplet (LD)-specific proteins such as adipophilin/adipose differentiation-related protein/perilipin 2 or TIP47/perilipin 3 show that both proteins colocalize with lipin-1α in the same cellular structures. Reduction of the expression levels of lipin-1 by small interfering RNA technology does not impair triacylglycerol biosynthesis but reduces the size of LDs formed in response to oleic acid. In agreement with these data, peritoneal macrophages from animals that carry a mutation in the Lpin-1 gene (fld animals) also produce less and smaller LDs in response to oleic acid. Mass spectrometry determinations demonstrate that the fatty acid composition of triacylglycerol in isolated LDs from lipin-1-deficient cells differs from that of control cells. Moreover, activation of cytosolic group IVA phospholipase A(2)α, a proinflammatory enzyme that is also involved in LD biogenesis, is also compromised in lipin-1-deficient cells. Collectively, these data suggest that lipin-1 associates with LDs and regulates the activation of cytosolic group IVA phospholipase A(2)α in human monocyte-derived macrophages.
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Affiliation(s)
- Martín Valdearcos
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, 47003 Valladolid, Spain
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Lai Y, Oslund RC, Bollinger JG, Henderson WR, Santana LF, Altemeier WA, Gelb MH, Hallstrand TS. Eosinophil cysteinyl leukotriene synthesis mediated by exogenous secreted phospholipase A2 group X. J Biol Chem 2010; 285:41491-500. [PMID: 20974857 DOI: 10.1074/jbc.m110.153338] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Secreted phospholipase A(2) group X (sPLA(2)-X) has recently been identified in the airways of patients with asthma and may participate in cysteinyl leukotriene (CysLT; C(4), D(4), and E(4)) synthesis. We examined CysLT synthesis and arachidonic acid (AA) and lysophospholipid release by eosinophils mediated by recombinant human sPLA(2)-X. We found that recombinant sPLA(2)-X caused marked AA release and a rapid onset of CysLT synthesis in human eosinophils that was blocked by a selective sPLA(2)-X inhibitor. Exogenous sPLA(2)-X released lysophospholipid species that arise from phospholipids enriched in AA in eosinophils, including phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine as well as plasmenyl phosphatidylcholine and phosphatidylethanolamine. CysLT synthesis mediated by sPLA(2)-X but not AA release could be suppressed by inhibition of cPLA(2)α. Exogenous sPLA(2)-X initiated Ser(505) phosphorylation of cPLA(2)α, an intracellular Ca(2+) flux, and translocation of cPLA(2)α and 5-lipoxygenase in eosinophils. Synthesis of CysLTs in response to sPLA(2)-X or lysophosphatidylcholine was inhibited by p38 or JNK inhibitors but not by a MEK 1/2 inhibitor. A further increase in CysLT synthesis was induced by the addition of sPLA(2)-X to eosinophils under conditions of N-formyl-methionyl-leucyl-phenylalanine-mediated cPLA(2)α activation. These results indicate that sPLA(2)-X participates in AA and lysophospholipid release, resulting in CysLT synthesis in eosinophils through a mechanism involving p38 and JNK MAPK, cPLA(2)α, and 5-lipoxygenase activation and resulting in the amplification of CysLT synthesis during cPLA(2)α activation. Transactivation of eosinophils by sPLA(2)-X may be an important mechanism leading to CysLT formation in the airways of patients with asthma.
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Affiliation(s)
- Ying Lai
- Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington 98195, USA
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Nakahama T, Nakanishi Y, Viscomi AR, Takaya K, Kitamoto K, Ottonello S, Arioka M. Distinct enzymatic and cellular characteristics of two secretory phospholipases A2 in the filamentous fungus Aspergillus oryzae. Fungal Genet Biol 2010; 47:318-31. [PMID: 20045482 DOI: 10.1016/j.fgb.2009.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 12/08/2009] [Accepted: 12/28/2009] [Indexed: 11/17/2022]
Abstract
Microbial secretory phospholipases A(2) (sPLA(2)s) are among the last discovered and least known members of this functionally diverse family of enzymes. We analyzed here two sPLA(2)s, named sPlaA and sPlaB, of the filamentous ascomycete Aspergillus oryzae. sPlaA and sPlaB consist of 222 and 160 amino acids, respectively, and share the conserved Cys and catalytic His-Asp residues typical of microbial sPLA(2)s. Two sPLA(2)s differ in pH optimum, Ca(2+) requirement and expression profile. The splaA mRNA was strongly upregulated in response to carbon starvation, oxidative stress and during conidiation, while splaB was constitutively expressed at low levels and was weakly upregulated by heat shock. Experiments with sPLA(2) overexpressing strains demonstrated that two enzymes produce subtly different phospholipid composition variations and also differ in their subcellular localization: sPlaA is most abundant in hyphal tips and secreted to the medium, whereas sPlaB predominantly localizes to the ER-like intracellular compartment. Both sPLA(2) overexpressing strains were defective in conidiation, which was more pronounced for sPlaB overexpressors. Although no major morphological abnormality was detected in either DeltasplaA or DeltasplaB mutants, hyphal growth of DeltasplaB, but not that of DeltasplaA, displayed increased sensitivity to H(2)O(2) treatment. These data indicate that two A. oryzae sPLA(2) enzymes display distinct, presumably non-redundant, physiological functions.
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Affiliation(s)
- Tomoyuki Nakahama
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Pérez-Chacón G, Astudillo AM, Balgoma D, Balboa MA, Balsinde J. Control of free arachidonic acid levels by phospholipases A2 and lysophospholipid acyltransferases. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:1103-13. [DOI: 10.1016/j.bbalip.2009.08.007] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 08/17/2009] [Accepted: 08/18/2009] [Indexed: 12/11/2022]
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Casas J, Valdearcos M, Pindado J, Balsinde J, Balboa MA. The cationic cluster of group IVA phospholipase A2 (Lys488/Lys541/Lys543/Lys544) is involved in translocation of the enzyme to phagosomes in human macrophages. J Lipid Res 2009; 51:388-99. [PMID: 19717620 DOI: 10.1194/jlr.m001461] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Group IVA cytosolic phospholipase A(2)alpha (cPLA(2)alpha) plays a role in the microbicidal machinery of immune cells by translocating to phagosomes to initiate the production of antimicrobial eicosanoids. In this work, we have studied the involvement of the cationic cluster of cPLA(2)alpha (Lys(488)/Lys(541)/Lys(543)/Lys(544)) in the translocation of the enzyme to the phagosomal cup in human macrophages responding to opsonized zymosan. Phagocytosis was accompanied by an increased mobilization of free arachidonic acid, which was strongly inhibited by pyrrophenone. In transfected cells, a catalytically active enhanced green fluorescent protein-cPLA(2)alpha translocated to the phagocytic cup, which was corroborated by frustrated phagocytosis experiments using immunoglobulin G-coated plates. However, a cPLA(2)alpha mutant in the polybasic cluster that cannot bind the anionic phospholipid phosphatidylinositol 4, 5-bisphosphate (PIP(2)) did not translocate to the phagocytic cup. Moreover, an enhanced yellow fluorescent protein (EYFP)-cPLA(2)alpha and an enhanced cyan fluorescent protein-pleckstrin homology (PH) domain of the phospholipase Cdelta1 (PLCdelta(1)) construct that specifically recognizes endogenous PIP(2) in the cells both localized at the same sites on the phagosome. High cellular expression of the PH domain inhibited EYFP-cPLA(2)alpha translocation. On the other hand, group V-secreted phospholipase A(2) and group VIA calcium-independent phospholipase A(2) were also studied, but the results indicated that neither of these translocated to the phagosome. Collectively, these data indicate that the polybasic cluster of cPLA(2)alpha (Lys(488)/Lys(541)/Lys(543)/Lys(544)) regulates the subcellular localization of the enzyme in intact cells under physiologically relevant conditions.
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Affiliation(s)
- Javier Casas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain
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Granata F, Nardicchi V, Loffredo S, Frattini A, Ilaria Staiano R, Agostini C, Triggiani M. Secreted phospholipases A(2): A proinflammatory connection between macrophages and mast cells in the human lung. Immunobiology 2009; 214:811-21. [PMID: 19628294 DOI: 10.1016/j.imbio.2009.06.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Secretory phospholipases A(2) (sPLA(2)) are an emerging class of mediators of inflammation. These enzymes accumulate in plasma and other biological fluids of patients with inflammatory, autoimmune and allergic diseases. sPLA(2)s are secreted at low levels in the normal airways and tend to increase during inflammatory lung diseases (e.g. bronchial asthma, chronic obstructive pulmonary disease, interstitial lung fibrosis, and sarcoidosis) as the result of plasma extravasation and/or local production. Such immune resident cells as macrophages and mast cells can be a source of sPLA(2)s in the lung. However, these cells are also targets for sPLA(2)s that sustain the activation programs of macrophages and mast cells with mechanism related to their enzymatic activity as well as to their capacity to interact with surface molecules (e.g., heparan sulfate proteoglycans, M-type receptor, mannose receptor). Recent evidence suggests that mast cells are a better source of extracellular sPLA(2)s than macrophages. On the other hand, macrophages appear to be a preferential target for sPLA(2)s. Anatomical association between macrophages and mast cells in the airways suggest that sPLA(2)s released by mast cells may activate in a paracrine fashion several macrophage functions relevant to the modulation of lung inflammation. Thus, sPLA(2)s may play a major role in inflammatory lung diseases by acting as a proinflammatory connection between macrophages and mast cells.
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Affiliation(s)
- Francescopaolo Granata
- Department of Clinical Immunology and Allergy and Center for Basic and Clinical Immunology Research, University of Naples Federico II, Naples, Italy
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Ruipérez V, Astudillo AM, Balboa MA, Balsinde J. Coordinate regulation of TLR-mediated arachidonic acid mobilization in macrophages by group IVA and group V phospholipase A2s. THE JOURNAL OF IMMUNOLOGY 2009; 182:3877-83. [PMID: 19265167 DOI: 10.4049/jimmunol.0804003] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Macrophages can be activated through TLRs for a variety of innate immune responses. In contrast with the wealth of data existing on TLR-dependent gene expression and resultant cytokine production, very little is known on the mechanisms governing TLR-mediated arachidonic acid (AA) mobilization and subsequent eicosanoid production. We have previously reported the involvement of both cytosolic group IVA phospholipase A(2) (cPLA(2)) and secreted group V phospholipase A(2) (sPLA(2)-V) in regulating the AA mobilization response of macrophages exposed to bacterial LPS, a TLR4 agonist. In the present study, we have used multiple TLR agonists to define the role of various PLA(2)s in macrophage AA release via TLRs. Activation of P388D(1) and RAW2647.1 macrophage-like cells via TLR1/2, TLR2, TLR3, TLR4, TLR6/2, and TLR7, but not TLR5 or TLR9, resulted in AA mobilization that appears to involve the activation of both cPLA(2) and sPLA(2) but not of calcium-independent phospholipase A(2). Furthermore, inhibition of sPLA(2)-V by RNA interference or by two cell-permeable compounds, namely scalaradial and manoalide, resulted in a marked reduction of the phosphorylation of ERK1/2 and cPLA(2) via TLR1/2, TLR2, TLR3, and TLR4, leading to attenuated AA mobilization. Collectively, the results suggest a model whereby sPLA(2)-V contributes to the macrophage AA mobilization response via various TLRs by amplifying cPLA(2) activation through the ERK1/2 phosphorylation cascade.
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Affiliation(s)
- Violeta Ruipérez
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Valladolid, Spain
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Titsworth WL, Liu NK, Xu XM. Role of secretory phospholipase a(2) in CNS inflammation: implications in traumatic spinal cord injury. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2008; 7:254-69. [PMID: 18673210 DOI: 10.2174/187152708784936671] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Secretory phospholipases A(2) (sPLA(2)s) are a subfamily of lipolytic enzymes which hydrolyze the acyl bond at the sn-2 position of glycerophospholipids to produce free fatty acids and lysophospholipids. These products are precursors of bioactive eicosanoids and platelet-activating factor (PAF). The hydrolysis of membrane phospholipids by PLA(2) is a rate-limiting step for generation of eicosanoids and PAF. To date, more than 10 isozymes of sPLA(2) have been found in the mammalian central nervous system (CNS). Under physiological conditions, sPLA(2)s are involved in diverse cellular responses, including host defense, phospholipid digestion and metabolism. However, under pathological situations, increased sPLA(2) activity and excessive production of free fatty acids and their metabolites may lead to inflammation, loss of membrane integrity, oxidative stress, and subsequent tissue injury. Emerging evidence suggests that sPLA(2) plays a role in the secondary injury process after traumatic or ischemic injuries in the brain and spinal cord. Importantly, sPLA(2) may act as a convergence molecule that mediates multiple key mechanisms involved in the secondary injury since it can be induced by multiple toxic factors such as inflammatory cytokines, free radicals, and excitatory amino acids, and its activation and metabolites can exacerbate the secondary injury. Blocking sPLA(2) action may represent a novel and efficient strategy to block multiple injury pathways associated with the CNS secondary injury. This review outlines the current knowledge of sPLA(2) in the CNS with emphasis placed on the possible roles of sPLA(2) in mediating CNS injuries, particularly the traumatic and ischemic injuries in the brain and spinal cord.
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Affiliation(s)
- W Lee Titsworth
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA
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The presence of a secretory phospholipase A2 in the nuclei of neuronal and glial cells of rat brain cortex. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:1345-52. [DOI: 10.1016/j.bbalip.2007.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 08/09/2007] [Accepted: 08/10/2007] [Indexed: 01/22/2023]
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Hallstrand TS, Chi EY, Singer AG, Gelb MH, Henderson WR. Secreted phospholipase A2 group X overexpression in asthma and bronchial hyperresponsiveness. Am J Respir Crit Care Med 2007; 176:1072-8. [PMID: 17901411 PMCID: PMC2176098 DOI: 10.1164/rccm.200707-1088oc] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
RATIONALE Secreted phospholipase A(2) enzymes (sPLA(2)s) play key regulatory roles in the biosynthesis of eicosanoids, such as the cysteinyl leukotrienes, but the role of these enzymes in the pathogenesis of asthma is not known. OBJECTIVES To establish if sPLA(2)s are overexpressed in the airways of patients with asthma, and to determine if these enzymes may play a role in the generation of eicosanoids in exercise-induced bronchoconstriction. METHODS Induced sputum samples were obtained from subjects with asthma with exercise-induced bronchoconstriction and nonasthmatic control subjects at baseline, and on a separate day 30 minutes after exercise challenge. The expression of the PLA(2)s in induced sputum cells and supernatant was determined by quantitative polymerase chain reaction, immunocytochemistry, and Western blot. MEASUREMENTS AND MAIN RESULTS The sPLA(2)s expressed at the highest levels in airway cells of subjects with asthma were groups X and XIIA. Group X sPLA(2) (sPLA(2)-X) was differentially overexpressed in asthma and localized to airway epithelial cells and bronchial macrophages. The gene expression, immunostaining in airway epithelial cells and bronchial macrophages, and the level of the extracellular sPLA(2)-X protein in the airways increased in response to exercise challenge in the asthma group, whereas the levels were lower and unchanged after challenge in nonasthmatic control subjects. CONCLUSIONS Increased expression of sPLA(2)-X may play a key role in the dysregulated eicosanoid synthesis in asthma.
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Affiliation(s)
- Teal S Hallstrand
- Division of Pulmonary and Critical Care, Department of Medicine, University of Washington, Box 356522, Seattle, WA 98195, USA.
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Ruipérez V, Casas J, Balboa MA, Balsinde J. Group V phospholipase A2-derived lysophosphatidylcholine mediates cyclooxygenase-2 induction in lipopolysaccharide-stimulated macrophages. THE JOURNAL OF IMMUNOLOGY 2007; 179:631-8. [PMID: 17579085 DOI: 10.4049/jimmunol.179.1.631] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activation of macrophages and macrophage cell lines by bacterial LPS elicits a delayed phase of PG biosynthesis that appears to be entirely mediated by cyclooxygenase-2 (COX-2). In previous work, we found that a catalytically active group V secreted phospholipase A(2) (sPLA(2)-V) was required for COX-2 induction, but the nature of the sPLA(2)-V metabolite involved was not defined. In this study, we identify lysophosphatidylcholine (lysoPC) as the sPLA(2)-V downstream mediator involved in COX-2 induction by LPS-stimulated macrophages. Inhibition of sPLA(2)-V by RNA interference or by the cell-permeable compound scalaradial blocked LPS-induced COX-2 expression, and this inhibition was overcome by incubating the cells with a nonhydrolyzable lysoPC analog, but not by arachidonic acid or oleic acid. Moreover, inhibition of sPLA(2)-V by scalaradial also prevented the activation of the transcription factor c-Rel, and such an inhibition was also selectively overcome by the lysoPC analog. Collectively, these results support a model whereby sPLA(2)-V hydrolysis of phospholipids upon LPS stimulation results in lysoPC generation, which in turn regulates COX-2 expression by a mechanism involving the transcriptional activity of c-Rel.
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Affiliation(s)
- Violeta Ruipérez
- Institute of Molecular Biology and Genetics, Spanish National Research Council and University of Valladolid School of Medicine, Valladolid, Spain
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Balestrieri B, Arm JP. Group V sPLA2: classical and novel functions. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1280-8. [PMID: 16945583 DOI: 10.1016/j.bbalip.2006.07.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 07/20/2006] [Accepted: 07/25/2006] [Indexed: 10/24/2022]
Abstract
Group V sPLA(2) is unique among the family of secretory sPLA(2) enzymes in being able to bind to cell membranes through both interfacial-binding and through binding to proteoglycan. The function of group V sPLA(2) as an enzyme and its cross-talk with cPLA(2)alpha in initiating eicosanoid generation is well documented. Evidence, though, is emerging on the ability of this molecule to act as a regulator of several intracellular and extracellular pathways independently of its ability to provide arachidonic acid for eicosanoid generation, acting within the cell or as a secreted enzyme. In this article we will provide an overview of the properties of the enzyme and how they relate to our current understanding of its function.
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Affiliation(s)
- Barbara Balestrieri
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA 02115, USA
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Balboa MA, Balsinde J. Oxidative stress and arachidonic acid mobilization. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:385-91. [PMID: 16651022 DOI: 10.1016/j.bbalip.2006.03.014] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 03/15/2006] [Accepted: 03/16/2006] [Indexed: 11/28/2022]
Abstract
Reactive oxygen species are known to contribute to tissue damage during injury and inflammation. However, these species can also be sensed by the cells and trigger intracellular signaling cascades. This review examines recent evidence on the involvement of reactive oxygen species in lipid signaling. Attention is focused on activation of phospholipase A2s, enzymes whose action on membrane phospholipids can also render molecules with opposite effects on cells. The participation of Ca2+-dependent and Ca2+-independent phospholipase A2s in arachidonic acid mobilization from phospholipids is discussed, with particular attention to the interplay between cytosolic and secreted Ca2+-dependent forms. The involvement of alternative routes for arachidonic acid mobilization under oxidative stress is also considered.
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Affiliation(s)
- María A Balboa
- Institute of Molecular Biology and Genetics Spanish Research Council and University of Valladolid School of Medicine Calle Sanz y Forés s/n,47003 Valladolid, Spain
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Balestrieri B, Hsu VW, Gilbert H, Leslie CC, Han WK, Bonventre JV, Arm JP. Group V secretory phospholipase A2 translocates to the phagosome after zymosan stimulation of mouse peritoneal macrophages and regulates phagocytosis. J Biol Chem 2006; 281:6691-8. [PMID: 16407308 PMCID: PMC1820836 DOI: 10.1074/jbc.m508314200] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously reported that group V secretory phospholipase A2 (sPLA2) amplifies the action of cytosolic phospholipase A2(cPLA2) alpha in regulating eicosanoid biosynthesis by mouse peritoneal macrophages stimulated with zymosan (Satake, Y., Diaz, B. L., Balestrieri, B., Lam, B. K., Kanaoka, Y., Grusby, M. J., and Arm, J. P. (2004) J. Biol. Chem. 279, 16488-16494). To further understand the role of group V sPLA2, we studied its localization in resting mouse peritoneal macrophages before and after stimulation with zymosan and the effect of deletion of the gene encoding group V sPLA2 on phagocytosis of zymosan. We report that group V sPLA2 is present in the Golgi apparatus and recycling endosome in the juxtanuclear region of resting peritoneal macrophages. Upon ingestion of zymosan by mouse peritoneal macrophages, group V sPLA2 is recruited to the phagosome. There it co-localizes with cPLA2alpha, 5-lipoxygenase, 5-lipoxygenase-activating protein, and leukotriene C4 synthase. Using immunostaining for the cysteinyl leukotrienes in carbodiimide-fixed cells, we show, for the first time, that the phagosome is a site of cysteinyl leukotriene formation. Furthermore, peritoneal macrophages from group V sPLA2-null mice demonstrated a >50% attenuation in phagocytosis of zymosan particles, which was restored by adenoviral expression of group V sPLA2 but IIA not group sPLA2. These data demonstrate that group V sPLA2 contributes to the innate immune response both through regulation of eicosanoid generation in response to a phagocytic stimulus and also as a component of the phagocytic machinery.
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Affiliation(s)
- Barbara Balestrieri
- From the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts 02115
| | - Victor W. Hsu
- From the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts 02115
| | - Huiya Gilbert
- From the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts 02115
| | - Christina C. Leslie
- Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
| | - Won K. Han
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts 02115
| | | | - Jonathan P. Arm
- From the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts 02115
- Partners Asthma Center, Brigham and Women’s Hospital, Boston, Massachusetts 02115
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Bonig H, Rohmer L, Papayannopoulou T. Long-term functional impairment of hemopoietic progenitor cells engineered to express the S1 catalytic subunit of pertussis toxin. Exp Hematol 2005; 33:689-98. [PMID: 15911093 DOI: 10.1016/j.exphem.2005.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 02/02/2005] [Accepted: 03/08/2005] [Indexed: 11/18/2022]
Abstract
OBJECTIVE A large body of data suggests that pertussis toxin (PTX)-sensitive G protein signals in mature and immature hemopoietic cells control their migration patterns in vitro and in vivo. These effects were derived after treatment of cells or animals with PTX. To circumvent several inherent problems of PTX holotoxin treatment, we expressed the S1 catalytic activity of PTX, thus blocking Gi protein signaling, in 32D murine myeloid progenitor cells and in primary human CD34+ cells, and studied its functional consequences. METHODS S1 was expressed using viral vectors. Effects of Gi protein blockade on proliferation, migration, adhesion, and gene expression were tested in vitro. RESULTS S1 expression was nontoxic for the cells; expression and function were stable long-term and not overridden by compensatory mechanisms. S1-transduced 32D cells and primary CD34+ cells migrated poorly and did not contract their cytoskeleton upon treatment with the chemoattractant stromal cell-derived factor -1 (SDF-1), similar to the phenotype induced by PTX treatment. Gene expression studies comparing S1-transduced and control 32D cells uncovered four genes, expression of which was regulated by Gi protein blockade. Of interest, although SDF-1 signaling was inhibited, comparison between SDF-1-treated and untreated cells suggests that SDF-1 stimulation does not depend on de novo gene expression in these cells. Furthermore, when injected into nonobese diabetic/severe combined immunodeficient mice, seeding of S1-expressing 32D cells to bone marrow was largely blocked. CONCLUSION Expression of S1 is an effective approach for studying long-term functional consequences of Gi protein blockade in hemopoietic cells in vitro and in vivo.
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Affiliation(s)
- Halvard Bonig
- Department of Medicine/Hematology, University of Washington, Seattle, WA 98195-7720, USA.
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