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Mangini M, D’Angelo R, Vinciguerra C, Payré C, Lambeau G, Balestrieri B, Charles JF, Mariggiò S. Multimodal regulation of the osteoclastogenesis process by secreted group IIA phospholipase A 2. Front Cell Dev Biol 2022; 10:966950. [PMID: 36105351 PMCID: PMC9467450 DOI: 10.3389/fcell.2022.966950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 07/25/2022] [Indexed: 01/21/2023] Open
Abstract
Increasing evidence points to the involvement of group IIA secreted phospholipase A2 (sPLA2-IIA) in pathologies characterized by abnormal osteoclast bone-resorption activity. Here, the role of this moonlighting protein has been deepened in the osteoclastogenesis process driven by the RANKL cytokine in RAW264.7 macrophages and bone-marrow derived precursor cells from BALB/cJ mice. Inhibitors with distinct selectivity toward sPLA2-IIA activities and recombinant sPLA2-IIA (wild-type or catalytically inactive forms, full-length or partial protein sequences) were instrumental to dissect out sPLA2-IIA function, in conjunction with reduction of sPLA2-IIA expression using small-interfering-RNAs and precursor cells from Pla2g2a knock-out mice. The reported data indicate sPLA2-IIA participation in murine osteoclast maturation, control of syncytium formation and resorbing activity, by mechanisms that may be both catalytically dependent and independent. Of note, these studies provide a more complete understanding of the still enigmatic osteoclast multinucleation process, a crucial step for bone-resorbing activity, uncovering the role of sPLA2-IIA interaction with a still unidentified receptor to regulate osteoclast fusion through p38 SAPK activation. This could pave the way for the design of specific inhibitors of sPLA2-IIA binding to interacting partners implicated in osteoclast syncytium formation.
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Affiliation(s)
- Maria Mangini
- Institute of Protein Biochemistry, National Research Council, Naples, Italy
| | - Rosa D’Angelo
- Institute of Protein Biochemistry, National Research Council, Naples, Italy
| | - Caterina Vinciguerra
- Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Christine Payré
- Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d’Azur, Valbonne Sophia Antipolis, France
| | - Gérard Lambeau
- Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d’Azur, Valbonne Sophia Antipolis, France
| | - Barbara Balestrieri
- Jeff and Penny Vinik Center for Translational Immunology Research, Department of Medicine, Division of Allergy and Clinical Immunology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Julia F. Charles
- Departments of Orthopaedic Surgery and Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Stefania Mariggiò
- Institute of Protein Biochemistry, National Research Council, Naples, Italy,*Correspondence: Stefania Mariggiò,
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2
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Kishi H, Yamaguchi K, Watanabe K, Nakamura K, Fujioka D, Kugiyama K. Deficiency of Phospholipase A 2 Receptor Exacerbates Autoimmune Myocarditis in Mice. Inflammation 2021; 43:1097-1109. [PMID: 32016628 DOI: 10.1007/s10753-020-01195-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Secretory phospholipase A2 (sPLA2) plays a critical role in the pathogenesis of various inflammatory diseases through production of pro-inflammatory eicosanoids. PLA2 receptor 1 (PLA2R) acts as a clearance receptor for sPLA2s. This study examined whether PLA2R plays a role in the pathogenesis of experimental autoimmune myocarditis using PLA2R-deficient (PLA2R KO) mice on a BALB/c background. Autoimmune myocarditis was induced by immunization with murine α-myosin heavy chain. In the immunostaining of PLA2R wild-type (WT) myocardium, PLA2R and sPLA2s were expressed in α-SMA+ cells and neutrophils, respectively. In immunoblot analyses, tissue from PLA2R KO myocardium after immunization had five to tenfold increases in the protein level of sPLA2-IB and sPLA2-IIA compared with PLA2R WT myocardium. However, the mRNA expression levels of these sPLA2s were similar in PLA2R KO and WT myocardium. Compared with PLA2R WT myocardium, PLA2R KO myocardium after immunization showed 40% increase in areas affected by infiltration of inflammatory cells, eight to tenfold increase in levels of PGE2 and TXB2, and a threefold increase in number of Th17 cells in heart infiltrates assessed by flow cytometric analysis. Finally, PGE2 promoted IL-23-induced expansion of Th17 cells in vitro. In conclusion, PLA2R-deficiency increased sPLA2-IB and sPLA2-IIA levels in the myocardium after immunization probably through impaired clearance, leading to increased levels of PGE2 in the myocardium. Elevated PGE2 induced Th17 cell expansion, exacerbating myocarditis in PLA2R KO mice. Thus, PLA2R plays an important role in pathogenesis of experimental autoimmune myocarditis.
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Affiliation(s)
- Hiroki Kishi
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kazuyuki Yamaguchi
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kazuhiro Watanabe
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kazuto Nakamura
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Daisuke Fujioka
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kiyotaka Kugiyama
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan. .,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.
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3
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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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4
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Hui DY. Group 1B phospholipase A 2 in metabolic and inflammatory disease modulation. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:784-788. [PMID: 30003964 DOI: 10.1016/j.bbalip.2018.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 12/11/2022]
Abstract
The group 1B phospholipase A2 (PLA2G1B) is a secreted phospholipase that catalyzes the hydrolytic removal of the sn-2 fatty acyl moiety from phospholipids. This enzyme is synthesized most abundantly in the pancreas and is also expressed in the lung. The first part of this review article focuses on the role of pancreatic-derived PLA2G1B in mediating lipid absorption and discusses how the PLA2G1B-derived metabolic product contributes to cardiometabolic diseases, including obesity, hyperinsulinemia, hyperlipidemia, and atherosclerosis. The anti-helminth properties of PLA2G1B will also be discussed. The second part of this review will focus on PLA2G1B expressed in the lung, and in vitro data suggest that how this enzyme may modulate lung inflammation via both hydrolytic activity-dependent and -dependent mechanisms. Finally, recent studies revealing a relationship between PLA2G1B and cancer will also be discussed. 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)
- David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; Department of Pathology, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, 2120 E. Galbraith Road, Cincinnati, OH 45237, United States.
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5
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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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6
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Rodriguez-Cuenca S, Pellegrinelli V, Campbell M, Oresic M, Vidal-Puig A. Sphingolipids and glycerophospholipids - The "ying and yang" of lipotoxicity in metabolic diseases. Prog Lipid Res 2017; 66:14-29. [PMID: 28104532 DOI: 10.1016/j.plipres.2017.01.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/30/2016] [Accepted: 01/05/2017] [Indexed: 12/14/2022]
Abstract
Sphingolipids in general and ceramides in particular, contribute to pathophysiological mechanisms by modifying signalling and metabolic pathways. Here, we present the available evidence for a bidirectional homeostatic crosstalk between sphingolipids and glycerophospholipids, whose dysregulation contributes to lipotoxicity induced metabolic stress. The initial evidence for this crosstalk originates from simulated models designed to investigate the biophysical properties of sphingolipids in plasma membrane representations. In this review, we reinterpret some of the original findings and conceptualise them as a sort of "ying/yang" interaction model of opposed/complementary forces, which is consistent with the current knowledge of lipid homeostasis and pathophysiology. We also propose that the dysregulation of the balance between sphingolipids and glycerophospholipids results in a lipotoxic insult relevant in the pathophysiology of common metabolic diseases, typically characterised by their increased ceramide/sphingosine pools.
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Affiliation(s)
- S Rodriguez-Cuenca
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK.
| | - V Pellegrinelli
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK
| | - M Campbell
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK
| | - M Oresic
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FI -20520 Turku, Finland
| | - A Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK; Wellcome Trust Sanger Institute, Hinxton, UK.
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7
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Takahashi S, Watanabe K, Watanabe Y, Fujioka D, Nakamura T, Nakamura K, Obata JE, Kugiyama K. C-type lectin-like domain and fibronectin-like type II domain of phospholipase A(2) receptor 1 modulate binding and migratory responses to collagen. FEBS Lett 2015; 589:829-35. [PMID: 25724334 DOI: 10.1016/j.febslet.2015.02.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/20/2015] [Accepted: 02/11/2015] [Indexed: 12/21/2022]
Abstract
Phospholipase A2 receptor 1 (PLA2R) mediates collagen-dependent migration. The mechanisms by which PLA2R interacts with collagen remain unclear. We produced HEK293 cells expressing full-length wild-type PLA2R or a truncated PLA2R that lacks fibronectin-like type II (FNII) domains or several regions of C-type lectin-like domain (CTLD). We show that the CTLD1-2 as well as the FNII domain of PLA2R are responsible for binding to collagen and for collagen-dependent migration. Thus, multiple regions and domains of the extracellular portion of PLA2R participate in the responses to collagen. These data suggest a potentially new mechanism for PLA2R-mediated biological response beyond that of a receptor for secretory PLA2.
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Affiliation(s)
- Soichiro Takahashi
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Kazuhiro Watanabe
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Yosuke Watanabe
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Daisuke Fujioka
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Takamitsu Nakamura
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Kazuto Nakamura
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Jun-ei Obata
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan
| | - Kiyotaka Kugiyama
- Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan; CREST, Japan Science and Technology Agency, Saitama, Japan.
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8
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Mishina H, Watanabe K, Tamaru S, Watanabe Y, Fujioka D, Takahashi S, Suzuki K, Nakamura T, Obata JE, Kawabata K, Yokota Y, Inoue O, Murakami M, Hanasaki K, Kugiyama K. Lack of phospholipase A2 receptor increases susceptibility to cardiac rupture after myocardial infarction. Circ Res 2013; 114:493-504. [PMID: 24305469 DOI: 10.1161/circresaha.114.302319] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
RATIONALE Recent evidence indicates that the biological effects of secretory phospholipase A2 (sPLA2) cannot be fully explained by its catalytic activity. A cell surface receptor for sPLA2 (PLA2 receptor 1 [PLA2R]) and its high-affinity ligands (including sPLA2-IB, sPLA2-IIE, and sPLA2-X) are expressed in the infarcted myocardium. OBJECTIVE This study asked whether PLA2R might play a pathogenic role in myocardial infarction (MI) using mice lacking PLA2R (PLA2R(-/-)). METHODS AND RESULTS MI was induced by permanent ligation of the left coronary artery. PLA2R(-/-) mice exhibited higher rates of cardiac rupture after MI compared with PLA2R wild-type (PLA2R(+/+)) mice (46% versus 21%, respectively; P=0.015). PLA2R(-/-) mice had a 31% decrease in collagen content and a 45% decrease in the number of α-smooth muscle actin-positive fibroblasts in the infarcted region compared with PLA2R(+/+) mice. PLA2R was primarily found in myofibroblasts in the infarcted region. PLA2R(-/-) myofibroblasts were impaired in collagen-dependent migration, proliferation, and activation of focal adhesion kinase in response to sPLA2-IB. Binding of sPLA2-IB to PLA2R promoted migration and proliferation of myofibroblasts through functional interaction with integrin β1, independent of the catalytic activity of sPLA2-IB. In rescue experiments, the injection of PLA2R(+/+) myofibroblasts into the infarcted myocardium prevented post-MI cardiac rupture and reversed the decrease in collagen content in the infarcted region in PLA2R(-/-) mice. CONCLUSIONS PLA2R deficiency increased the susceptibility to post-MI cardiac rupture through impaired healing of the infarcted region. This might be partly explained by a reduction in integrin β1-mediated migratory and proliferative responses of PLA2R(-/-) myofibroblasts.
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Affiliation(s)
- Hideto Mishina
- From the Department of Internal Medicine II, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan (H.M., K.W., S.T., Y.W., D.F., S.T., K.S., T.N., J.O., K.K., K.K.); Shionogi Research Laboratories, Shionogi & Co Ltd, Osaka, Japan (Y.Y., K.H.); Department of Clinical and Laboratory Medicine, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan (O.I.); and Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan (M.M.)
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9
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Tamaru S, Mishina H, Watanabe Y, Watanabe K, Fujioka D, Takahashi S, Suzuki K, Nakamura T, Obata JE, Kawabata K, Yokota Y, Murakami M, Hanasaki K, Kugiyama K. Deficiency of phospholipase A2 receptor exacerbates ovalbumin-induced lung inflammation. THE JOURNAL OF IMMUNOLOGY 2013; 191:1021-8. [PMID: 23817419 DOI: 10.4049/jimmunol.1300738] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Secretory phospholipase A2 (sPLA2) plays a critical role in the genesis of lung inflammation through proinflammatory eicosanoids. A previous in vitro experiment showed a possible role of cell surface receptor for sPLA2 (PLA2R) in the clearance of extracellular sPLA2. PLA2R and groups IB and X sPLA2 are expressed in the lung. This study examined a pathogenic role of PLA2R in airway inflammation using PLA2R-deficient (PLA2R(-/-)) mice. Airway inflammation was induced by immunosensitization with OVA. Compared with wild-type (PLA2R(+/+)) mice, PLA2R(-/-) mice had a significantly greater infiltration of inflammatory cells around the airways, higher levels of groups IB and X sPLA2, eicosanoids, and Th2 cytokines, and higher numbers of eosinophils and neutrophils in bronchoalveolar lavage fluid after OVA treatment. In PLA2R(-/-) mice, intratracheally instilled [(125)I]-labeled sPLA2-IB was cleared much more slowly from bronchoalveolar lavage fluid compared with PLA2R(+/+) mice. The degradation of the instilled [(125)I]-labeled sPLA2-IB, as assessed by trichloroacetic acid-soluble radioactivity in bronchoalveolar lavage fluid after instillation, was lower in PLA2R(-/-) mice than in PLA2R(+/+) mice. In conclusion, PLA2R deficiency increased sPLA2-IB and -X levels in the lung through their impaired clearance from the lung, leading to exaggeration of lung inflammation induced by OVA treatment in a murine model.
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Affiliation(s)
- Shun Tamaru
- Department of Internal Medicine II, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
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10
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 804] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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11
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A direct role for secretory phospholipase A2 and lysophosphatidylcholine in the mediation of LPS-induced gastric injury. Shock 2010; 33:634-8. [PMID: 19940811 DOI: 10.1097/shk.0b013e3181cb9266] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Endotoxemia from sepsis can injure the gastrointestinal tract through mechanisms that have not been fully elucidated. We have shown that LPS induces an increase in gastric permeability in parallel with the luminal appearance of secretory phospholipase A2 (sPLA2) and its product, lysophosphatidylcholine (lyso-PC). We proposed that sPLA2 acted on the gastric hydrophobic barrier, composed primarily of phosphatidylcholine (PC), to degrade it and produce lyso-PC, an agent that is damaging to the mucosa. In the present study, we have tested whether lyso-PC and/or sPLA2 have direct damaging effects on the hydrophobic barriers of synthetic and mucosal surfaces. Rats were administered LPS (5 mg/kg, i.p.), and gastric contents were collected 5 h later for analysis of sPLA2 and lyso-PC content. Using these measured concentrations, direct effects of sPLA2 and lyso-PC were determined on (a) surface hydrophobicity as detected with an artificial PC surface and with intact gastric mucosa (contact angle analysis) and (b) cell membrane disruption of gastric epithelial cells (AGS). Both lyso-PC and sPLA2 increased significantly in the collected gastric juice of LPS-treated rats. Using similar concentrations to the levels in gastric juice, the contact angle of PC-coated slides declined after incubation with either pancreatic sPLA2 or lyso-PC. Similarly, gastric contact angles seen in control rats were significantly decreased in sPLA2 and lyso-PC-treated rats. In addition, we observed dose-dependent injurious effects of both lyso-PC and sPLA2 in gastric AGS cells. An LPS-induced increase in sPLA2 activity in the gastric lumen and its product, lyso-PC, are capable of directly disrupting the gastric hydrophobic layer and may contribute to gastric barrier disruption and subsequent inflammation.
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12
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Agassandian M, Miakotina OL, Andrews M, Mathur SN, Mallampalli RK. Pseudomonas aeruginosa and sPLA2 IB stimulate ABCA1-mediated phospholipid efflux via ERK-activation of PPARalpha-RXR. Biochem J 2007; 403:409-20. [PMID: 17223797 PMCID: PMC1876365 DOI: 10.1042/bj20061364] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacterial infection triggers an acute inflammatory response that might alter phospholipid metabolism. We have investigated the acute-phase response of murine lung epithelia to Pseudomonas aeruginosa infection. Ps. aeruginosa triggered secretion of the pro-inflammatory lipase, sPLA2 IB (phospholipase A2 IB), from lung epithelium. Ps. aeruginosa and sPLA2 IB each stimulated basolateral PtdCho (phosphatidylcholine) efflux in lung epithelial cells. Pre-treatment of cells with glyburide, an inhibitor of the lipid-export pump, ABCA1 (ATP-binding cassette transporter A1), attenuated Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux. Effects of Ps. aeruginosa and sPLA2 IB were completely abolished in human Tangier disease fibroblasts, cells that harbour an ABCA1 genetic defect. Ps. aeruginosa and sPLA2 IB induced the heterodimeric receptors, PPARa (peroxisome-proliferator-activated receptor-a) and RXR (retinoid X receptor), factors known to modulate ABCA1 gene expression. Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux was blocked with PD98059, a p44/42 kinase inhibitor. Transfection with MEK1 (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase 1), a kinase upstream of p44/42, increased PPARa and RXR expression co-ordinately with increased ABCA1 protein. These results suggest that pro-inflammatory effects of Ps. aeruginosa involve release of an sPLA2 of epithelial origin that, in part, via distinct signalling molecules, transactivates the ABCA1 gene, leading to export of phospholipid.
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Affiliation(s)
- Marianna Agassandian
- Department of Internal Medicine, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA.
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13
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Rouault M, Le Calvez C, Boilard E, Surrel F, Singer A, Ghomashchi F, Bezzine S, Scarzello S, Bollinger J, Gelb MH, Lambeau G. Recombinant production and properties of binding of the full set of mouse secreted phospholipases A2 to the mouse M-type receptor. Biochemistry 2007; 46:1647-62. [PMID: 17279628 DOI: 10.1021/bi062119b] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To date, 12 secreted phospholipases A2 (sPLA2s) have been identified in the mouse species and divided into three structural collections (I/II/V/X, III, and XII). On the basis of their different molecular properties and tissue distributions, each sPLA2 is likely to exert distinct functions by acting as an enzyme or ligand for specific soluble proteins or receptors, among which the M-type receptor is the best-characterized target. Here, we present the properties of binding of the full set of mouse sPLA2s to the mouse M-type receptor. All enzymes have been produced in Escherichia coli or insect cells, and their properties of binding to the cloned and native M-type receptor have been determined. sPLA2s IB, IIA, IIE, IIF, and X are high-affinity ligands (K0.5 = 0.3-3 nM); sPLA2s IIC and V are low-affinity ligands (K0.5 = 30-75 nM), and sPLA2s IID, III, XIIA, and XIIB bind only very weakly or do not bind to the M-type receptor (K0.5 > 100 nM). Three exogenous parvoviral group XIII PLA2s and two fungal group XIV sPLA2s do not bind to the receptor. Together, these results indicate that the mouse M-type receptor is selective for only a subset of mouse sPLA2s from the group I/II/V/X structural collection. Binding of mouse sPLA2s to a recombinant soluble mouse M-type receptor leads in all cases to inhibition of enzymatic activity, and the extent of deglycosylation of the receptor decreases yet does not abolish sPLA2 binding. The physiological meaning of binding of sPLA2 to the M-type receptor is discussed on the basis of our current knowledge of sPLA2 functions.
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Affiliation(s)
- Morgane Rouault
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR 6097, 660 route des Lucioles, Sophia Antipolis, 06560 Valbonne, France
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14
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Boilard E, Rouault M, Surrel F, Le Calvez C, Bezzine S, Singer A, Gelb MH, Lambeau G. Secreted Phospholipase A2Inhibitors Are Also Potent Blockers of Binding to the M-Type Receptor†. Biochemistry 2006; 45:13203-18. [PMID: 17073442 DOI: 10.1021/bi061376d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian secreted phospholipases A(2) (sPLA(2)s) constitute a family of structurally related enzymes that are likely to play numerous biological roles because of their phospholipid hydrolyzing activity and binding to soluble and membrane-bound proteins, including the M-type receptor. Over the past decade, a number of competitive inhibitors have been developed against the inflammatory-type human group IIA (hGIIA) sPLA(2) with the aim of specifically blocking its catalytic activity and pathophysiological functions. The fact that many of these inhibitors, including the indole analogue Me-Indoxam, inhibit several other sPLA(2)s that bind to the M-type receptor prompted us to investigate the impact of Me-Indoxam and other inhibitors on the sPLA(2)-receptor interaction. By using a Ca(2+) loop mutant derived from a venom sPLA(2) which is insensitive to hGIIA inhibitors but still binds to the M-type receptor, we demonstrate that Me-Indoxam dramatically decreases the affinity of various sPLA(2)s for the receptor, yet an sPLA(2)-Me-Indoxam-receptor complex can form at very high sPLA(2) concentrations. Me-Indoxam inhibits the binding of iodinated mouse sPLA(2)s to the mouse M-type receptor expressed on live cells but also enhances binding of sPLA(2) to phospholipids. Because Me-Indoxam and other competitive inhibitors protrude out of the sPLA(2) catalytic groove, it is likely that the inhibitors interfere with the sPLA(2)-receptor interaction by steric hindrance and to different extents that depend on the type of sPLA(2) and inhibitor. Our finding suggests that the various anti-inflammatory therapeutic effects of sPLA(2) inhibitors may be due not only to inhibition of enzymatic activity but also to modulation of binding of sPLA(2) to the M-type receptor or other as yet unknown protein targets.
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Affiliation(s)
- Eric Boilard
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR 6097, 660 route des Lucioles, Sophia-Antipolis, 06560 Valbonne, France
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15
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Schaloske RH, Dennis EA. The phospholipase A2 superfamily and its group numbering system. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1246-59. [PMID: 16973413 DOI: 10.1016/j.bbalip.2006.07.011] [Citation(s) in RCA: 627] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 07/05/2006] [Accepted: 07/29/2006] [Indexed: 01/07/2023]
Abstract
The superfamily of phospholipase A(2) (PLA(2)) enzymes currently consists of 15 Groups and many subgroups and includes five distinct types of enzymes, namely the secreted PLA(2)s (sPLA(2)), the cytosolic PLA(2)s (cPLA(2)), the Ca(2+) independent PLA(2)s (iPLA(2)), the platelet-activating factor acetylhydrolases (PAF-AH), and the lysosomal PLA(2)s. In 1994, we established the systematic Group numbering system for these enzymes. Since then, the PLA(2) superfamily has grown continuously and over the intervening years has required several updates of this Group numbering system. Since our last update, a number of new PLA(2)s have been discovered and are now included. Additionally, tools for the investigation of PLA(2)s and approaches for distinguishing between the different Groups are described.
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Affiliation(s)
- Ralph H Schaloske
- Department of Pharmacology, School of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0601, USA
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16
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Engelberg H. Pathogenic factors in vascular dementia and Alzheimer's disease. Multiple actions of heparin that probably are beneficial. Dement Geriatr Cogn Disord 2005; 18:278-98. [PMID: 15286460 DOI: 10.1159/000080034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/04/2004] [Indexed: 12/22/2022] Open
Abstract
The following areas are discussed in this review: atherogenesis; cerebrovascular factors; hypoperfusion; beta-amyloid production; beta-amyloid fibril formation; beta-sheets; metal cations; reactive oxygen species/free radicals; chronic inflammatory factors; endogenous plasma heparin; lipoprotein lipase; polyamines; protein kinase C; casein kinases; phospholipase A2; serine proteases; myeloperoxidase; cyclooxygenase 2; cysteine proteases; caspases; proprotein convertases; aspartic proteases; cyclin proteinases; thrombin; tau hyperphosphorylation; advanced glycosylation end products; activator protein 1; calcium; apolipoprotein E epsilon4; histamine; blood-brain barrier; glutamate; transglutaminase; insulin-like growth factor 1.
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17
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Choi YA, Lim HK, Kim JR, Lee CH, Kim YJ, Kang SS, Baek SH. Group IB secretory phospholipase A2 promotes matrix metalloproteinase-2-mediated cell migration via the phosphatidylinositol 3-kinase and Akt pathway. J Biol Chem 2004; 279:36579-85. [PMID: 15220345 DOI: 10.1074/jbc.m314235200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Secretory phospholipase A(2) (sPLA(2)), abundantly expressed in various cells including fibroblasts, is able to promote proliferation and migration. Degradation of collagenous extracellular matrix by matrix metalloproteinase (MMP) plays a role in the pathogenesis of various destructive disorders, such as rheumatoid arthritis, tumor invasion, and metastasis. Here we show that group IB PLA(2) increased pro-MMP-2 activation in NIH3T3 fibroblasts. MMP-2 activity was stimulated by group IB PLA(2) in a dose- and time-dependent manner. Consistent with MMP-2 activation, sPLA(2) decreased expression of type IV collagen. These effects are due to the reduction of tissue inhibitor of metalloproteinase-2 (TIMP-2) and the activation of the membrane type1-MMP (MT1-MMP). The decrease of TIMP-2 levels in conditioned media and the increase of MT1-MMP levels in plasma membrane were observed. In addition, treatment of cells with decanoyl Arg-Val-Lys-Arg-chloromethyl ketone, an inhibitor of pro-MT1-MMP, suppressed sPLA(2)-mediated MMP-2 activation, whereas treatment with bafilomycin A1, an inhibitor of H(+)-ATPase, sustained MMP-2 activation by sPLA(2). The involvement of phosphatidylinositol 3-kinase (PI3K) and Akt in the regulation of MMP-2 activity was further suggested by the findings that PI3K and Akt were phosphorylated by sPLA(2). Expression of p85alpha and Akt mutants, or pretreatment of cells with LY294002, a PI3K inhibitor, attenuated sPLA(2)-induced MMP-2 activation and migration. Taken together, these results suggest that sPLA(2) increases the pro-MMP-2 activation and migration of fibroblasts via the PI3K and Akt-dependent pathway. Because MMP-2 is an important factor directly involved in the control of cell migration and the turnover of extracellular matrix, our study may provide a mechanism for sPLA(2)-promoted fibroblasts migration.
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Affiliation(s)
- Young-Ae Choi
- Department of Biochemistry and Molecular Biology, Yeungnam University, 317-1 Daemyung 5-Dong, Nam-Gu, Daegu 705-717, South Korea
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18
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Delton-Vandenbroucke I, Lemaire P, Lagarde M, Laugier C. Hydrolysis of nuclear phospholipids in relation with proliferative state in uterine stromal cells. Biochimie 2004; 86:269-74. [PMID: 15194229 DOI: 10.1016/j.biochi.2004.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Accepted: 04/01/2004] [Indexed: 01/12/2023]
Abstract
The current study examined the metabolism of phospholipid (PL) in the whole cell homogenate and in the nuclear fraction in proliferative and non-proliferative uterine stromal cells (U(III) cells). Growth arrested cells were obtained either from contact-inhibited confluent cells or from proliferative cells treated with aristolochic acid (AR) for 2 days. Fatty acid composition and fatty acid amount of both total and nuclear PL were not significantly different between proliferative, confluent and AR-treated cells. In contrast, marked differences were observed in the incorporation of [(3)H]AA, with greater incorporation in proliferative cells than in confluent or AR-treated cells, particularly in nuclear PL. Considering endogenous level of arachidonic acid (AA) in total and nuclear PL, we found that AA turnover in nuclear PL was especially high compared to that in total PL and that this difference was accentuated in proliferative cells compared to non-proliferative cells. Interestingly, [(3)H]AA incorporation and AA turnover in proliferative, confluent and AR-treated cells vary accordingly to the expression, activity and/or content of pancreatic phospholipase A(2) (PLA(2)-I) in the nuclear compartment of these cells that we reported in previous studies. The changes in metabolism of nuclear PL during cell proliferation are consistent with an enhanced PL hydrolysis that could involve PLA(2)-I.
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19
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Marchand-Adam S, Marchal J, Cohen M, Soler P, Gerard B, Castier Y, Lesèche G, Valeyre D, Mal H, Aubier M, Dehoux M, Crestani B. Defect of hepatocyte growth factor secretion by fibroblasts in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 2003; 168:1156-61. [PMID: 12947024 DOI: 10.1164/rccm.200212-1514oc] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hepatocyte growth factor (HGF) is a growth factor that protects alveolar epithelial cells from pulmonary fibrosis in various animal models. We compared in vitro HGF production by human lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF, n = 8) and from control subjects (n = 6). Basal HGF secretion by IPF fibroblasts was decreased by 50% when compared with control fibroblasts (p < 0.05). HGF was secreted mainly in the cleaved mature form, both in IPF and control fibroblasts. HGF messenger RNA levels were reduced in IPF fibroblasts. Prostaglandin (PG) E2 secretion by IPF fibroblasts was low when compared with control subjects (p < 0.05). After the addition of PGE2 (10-6 M) or dibutyryl cyclic AMP (10-3 M), HGF secretion by IPF fibroblasts reached the level of control subjects. Inhibition of PGE2 synthesis with indomethacin reduced HGF secretion by control fibroblasts but had no effect on IPF fibroblasts. HGF secretion by control fibroblasts was also slightly inhibited by transforming growth factor (TGF)-beta1 and stimulated by anti-TGF-beta antibody, whereas both agents had no effect on IPF fibroblasts. Our results demonstrate a defect in HGF production by IPF fibroblasts that seems secondary to a defect in PGE2 secretion.
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Affiliation(s)
- Sylvain Marchand-Adam
- INSERM unit 408, Faculté Xavier Bichat, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, 16 rue Henri Huchard, 75877 Paris Cedex 18, France
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20
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Cher CDN, Armugam A, Lachumanan R, Coghlan MW, Jeyaseelan K. Pulmonary inflammation and edema induced by phospholipase A2: global gene analysis and effects on aquaporins and Na+/K+-ATPase. J Biol Chem 2003; 278:31352-60. [PMID: 12746451 DOI: 10.1074/jbc.m302446200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Victims of snakebite quickly succumb to severe respiratory failure, which can be fatal if left untreated. One of the most toxic components of snake venom is phospholipase A2 (PLA2; EC 3.1.1.4). PLA2 isolated from the elapid, Naja sputatrix, induced pulmonary inflammation and edema when administered intravenously and intratracheally to rats. Analysis of pulmonary gene expression profiles using oligonucleotide microarrays revealed 60 genes whose expression was altered by at least 3-fold in response to intratracheal instillation of PLA2 for 3 h as compared with controls. In addition to genes encoding cytokines and chemokines responsible for inflammatory processes, the Na+/K+-ATPase gene has been found to be involved in edema formation. Real-time PCR, Western blot, and immunohistochemical analyses confirmed that the expression of AQP1 and AQP5 mRNAs and proteins was decreased. Besides providing an experimental model for studies on the pathophysiology of the lung, this investigation yields a clue to the mechanisms by which endogenous PLA2s could mediate inflammation in conditions such as allergy and rheumatoid arthritis.
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Affiliation(s)
- Charmian D N Cher
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, S117597, Singapore
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21
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Beck S, Lambeau G, Scholz-Pedretti K, Gelb MH, Janssen MJW, Edwards SH, Wilton DC, Pfeilschifter J, Kaszkin M. Potentiation of tumor necrosis factor alpha-induced secreted phospholipase A2 (sPLA2)-IIA expression in mesangial cells by an autocrine loop involving sPLA2 and peroxisome proliferator-activated receptor alpha activation. J Biol Chem 2003; 278:29799-812. [PMID: 12782627 DOI: 10.1074/jbc.m211763200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
In rat mesangial cells, exogenously added secreted phospholipases A2 (sPLA2s) potentiate the expression of pro-inflammatory sPLA2-IIA first induced by cytokines like tumor necrosis factor-alpha (TNFalpha) and interleukin-1 beta. The transcriptional pathway mediating this effect is, however, unknown. Because products of PLA2 activity are endogenous activators of peroxisome proliferator-activated receptor alpha (PPAR alpha, we postulated that sPLA2s mediate their effects on sPLA2-IIA expression via sPLA2 activity and subsequent PPAR alpha activation. This study shows that various sPLA2s, including venom enzymes, human sPLA2-IIA, and wild-type and catalytically inactive H48Q mutant of porcine pancreatic sPLA2-IB, enhance the TNF alpha-induced sPLA2-IIA expression at the mRNA and protein levels. In cells transfected with luciferase sPLA2-IIA promoter constructs, sPLA2s are active only when the promoter contains a functional PPRE-1 site. The effect of exogenous sPLA2s is also blocked by the PPAR alpha inhibitor MK886. Interestingly, the expression of sPLA2-IIA induced by TNF alpha alone is also attenuated by MK886, by the sPLA2-IIA inhibitor LY311727, by heparinase, which prevents the binding of sPLA2-IIA to heparan sulfate proteoglycans, and by the specific cPLA2-alpha inhibitor pyrrolidine-1. Together, these data indicate that sPLA2-IIA released from mesangial cells by TNF alpha stimulates its own expression via an autocrine loop involving cPLA2 and PPAR alpha. This signaling pathway is also used by exogenously added sPLA2s including pancreatic sPLA2-IB and is distinct from that used by TNF alpha.
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Affiliation(s)
- Sabine Beck
- Center of Pharmacology, University Hospital Frankfurt, 60590 Frankfurt, Germany
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22
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Lee YH, Magnuson MA, Muppala V, Chen SS. Liver-specific reactivation of the inactivated Hnf-1alpha gene: elimination of liver dysfunction to establish a mouse MODY3 model. Mol Cell Biol 2003; 23:923-32. [PMID: 12529398 PMCID: PMC140695 DOI: 10.1128/mcb.23.3.923-932.2003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Mice deficient in hepatocyte nuclear factor 1 alpha (HNF-1alpha) develop dwarfism, liver dysfunction, and type 2 diabetes mellitus. Liver dysfunction in HNF-1alpha-null mice includes severe hepatic glycogen accumulation and dyslipidemia. The liver dysfunction may appear as soon as 2 weeks after birth. Since the HNF-1alpha-null mice become diabetic 2 weeks after birth, the early onset of the liver dysfunction is unlikely to be due to the diabetic status of the mice. More likely, it is due directly to the deficiency of HNF-1alpha in liver. Although the HNF-1alpha-null mice have an average life span of 1 year, the severe liver phenotype has thwarted attempts to study the pathogenesis of maturity-onset diabetes of the young type 3 (MODY3) and to examine therapeutic strategies for diabetes prevention and treatment in these mice. To circumvent this problem, we have generated a new Hnf-1alpha mutant mouse line, Hnf-1alpha(kin/kin), using gene targeting to inactivate the Hnf-1alpha gene and at the same time, to incorporate the Cre-loxP DNA recombination system into the locus for later revival of the Hnf-1alpha gene in tissues by tissue-specifically expressed Cre recombinase. The Hnf-1alpha(kin/kin) mice in which the expression of HNF-1alpha was inactivated in germ line cells were indistinguishable from the HNF-1alpha-null mice with regard to both the diabetes and liver phenotypes. Intriguingly, when the inactivated Hnf-1alpha gene was revived in liver (hepatic Hnf-1alpha revived) by the Cre recombinase driven by an albumin promoter, the Hnf-1alpha(kin/kin) mice, although severely diabetic, grew normally and did not develop any of the liver dysfunctions. In addition, we showed that the expression of numerous genes in pancreas, including a marker gene for pancreas injury, was affected by liver dysfunction but not by the deficiency of HNF-1alpha in pancreas. Thus, our hepatic-Hnf-1alpha-revived mice may serve as a useful mouse model to study the human MODY3 disorder.
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Affiliation(s)
- Ying-Hue Lee
- Laboratory of Molecular Pathology, Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan.
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