title: Dexamethasone enhances ATP-induced inflammatory responses in endothelial cells.
abstract: The purinergic nucleotide ATP is released from stressed cells and is implicated in vascular inflammation. Glucocorticoids are essential to stress responses and are used therapeutically, yet little information is available that describes the effects of glucocorticoids on ATP-induced inflammation. In a human microvascular endothelial cell line, extracellular ATP-induced interleukin (IL)-6 secretion in a dose- and time-dependent manner. When cells were pretreated with dexamethasone, a prototypic glucocorticoid, ATP-induced IL-6 production was enhanced in a time- and dose-dependent manner. Mifepristone, a glucocorticoid receptor antagonist, blocked these effects. ATP-induced IL-6 release was significantly inhibited by a phospholipase C inhibitor [1-[6-[((17β)-3-methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione (U73122)] (63.2 ± 3%, p < 0.001) and abolished by a p38 mitogen-activated protein kinase inhibitor [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB 203580)] (88 ± 1%, p < 0.001). Cells treated with dexamethasone induced mRNA expression of the purinergic P2Y(2) receptor (P2Y(2)R) 1.8- ± 0.1-fold and, when stimulated with ATP, enhanced Ca(2+) release and augmented IL-6 mRNA expression. Silencing of the P2Y(2)R by its small interfering RNA decreased ATP-induced IL-6 production by 81 ± 1% (p < 0.001). Dexamethasone enhanced the transcription rate of P2Y(2)R mRNA and induced a dose-related increase in the activity of the P2Y(2)R promoter. Furthermore, dexamethasone-enhanced ATP induction of adhesion molecule transcription and augmented the release of IL-8. Dexamethasone leads to an unanticipated enhancement of endothelial inflammatory mediator production by extracellular ATP via a P2Y(2)R-dependent mechanism. These data define a novel positive feedback loop of glucocorticoids and ATP-induced endothelial inflammation.
authors.affiliation: Critical Care Medicine Department, Clinical Center and Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institutes of Health, Bethesda, Maryland 20892-1662, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.forename: Zhan-Guo
authors.initials: ZG
authors.lastname: Gao
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Jacobson
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Suffredini
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000235:genetics; D002460:Cell Line; D018932:Chemokine CCL2 / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D015735:Mifepristone / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics; D009711:Nucleotides / Q000494:pharmacology; D058919:Purinergic P2 Receptor Antagonists / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors / Q000378:metabolism; D058473:Receptors, Purinergic P2Y2 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013498:Suramin / Q000494:pharmacology; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C111835:CCL2 protein, human; D015815:Cell Adhesion Molecules; D018932:Chemokine CCL2; D016207:Cytokines; D004268:DNA-Binding Proteins; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D009687:Nuclear Proteins; D009711:Nucleotides; D058919:Purinergic P2 Receptor Antagonists; D034741:RNA, Small Interfering; D011965:Receptors, Glucocorticoid; D058473:Receptors, Purinergic P2Y2; D015735:Mifepristone; D013498:Suramin; D003907:Dexamethasone; D000255:Adenosine Triphosphate; D048051:p38 Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3
references.citation: Surgery. 1976 Jun;79(6):666-8
references.pmid: 1273752
references.citation: Pharmacol Rev. 2006 Sep;58(3):281-341
references.pmid: 16968944
references.citation: Clin Microbiol Infect. 2009 Apr;15(4):308-18
references.pmid: 19416302
references.citation: Mol Pharmacol. 1996 Aug;50(2):224-9
references.pmid: 8700127
references.citation: J Immunol. 1993 Mar 1;150(5):1999-2006
references.pmid: 8436830
references.citation: Pharmacology. 2008;82(2):164-70
references.pmid: 18679041
references.citation: Science. 2006 Dec 15;314(5806):1792-5
references.pmid: 17170310
references.citation: J Invest Dermatol. 1993 Jan;100(1):111S-115S
references.pmid: 8423379
references.citation: J Interferon Cytokine Res. 1999 Feb;19(2):91-104
references.pmid: 10090394
references.citation: Purinergic Signal. 2008 Mar;4(1):1-20
references.pmid: 18368530
references.citation: J Immunol. 2009 Oct 1;183(7):4521-9
references.pmid: 19734210
references.citation: Am J Physiol. 1997 Apr;272(4 Pt 1):E616-20
references.pmid: 9142882
references.citation: J Trauma. 2003 Aug;55(2):290-7
references.pmid: 12913640
references.citation: Am J Physiol Cell Physiol. 2002 Feb;282(2):C289-301
references.pmid: 11788340
references.citation: J Invest Dermatol. 2006 May;126(5):1017-27
references.pmid: 16410784
references.citation: Endocrinology. 2002 May;143(5):1571-4
references.pmid: 11956136
references.citation: Crit Rev Immunol. 2008;28(3):229-48
references.pmid: 19024347
references.citation: Acta Pharmacol Sin. 2005 Feb;26(2):199-204
references.pmid: 15663899
references.citation: Shock. 2008 Aug;30(2):173-7
references.pmid: 18091570
references.citation: FASEB J. 2002 Jan;16(1):61-71
references.pmid: 11772937
references.citation: PLoS One. 2008 Jul 09;3(7):e2599
references.pmid: 18612415
references.citation: J Immunol. 1996 Dec 15;157(12):5627-37
references.pmid: 8955215
references.citation: Eur J Endocrinol. 2007 Nov;157(5):545-59
references.pmid: 17984234
references.citation: Clin Chem. 2007 Feb;53(2):318-25
references.pmid: 17185366
references.citation: Lancet. 2002 Jul 20;360(9328):219-23
references.pmid: 12133657
references.citation: Trends Biochem Sci. 2005 Jan;30(1):1-4
references.pmid: 15653317
references.citation: Am J Physiol Lung Cell Mol Physiol. 2005 Nov;289(5):L890-5
references.pmid: 16024720
references.citation: Ann Clin Lab Sci. 1979 Mar-Apr;9(2):121-32
references.pmid: 453786
references.citation: Br J Pharmacol. 1997 Aug;121(8):1692-9
references.pmid: 9283705
references.citation: J Trauma. 1999 Oct;47(4):673-83
references.pmid: 10528601
references.citation: Exp Dermatol. 2008 Sep;17(9):752-60
references.pmid: 18341570
references.citation: Mol Pharmacol. 1997 Jan;51(1):97-108
references.pmid: 9016351
references.citation: Sci Signal. 2009 Feb 03;2(56):pe6
references.pmid: 19193605
references.citation: Pharmacol Ther. 2006 Nov;112(2):358-404
references.pmid: 16784779
references.citation: Annu Rev Pathol. 2009;4:71-95
references.pmid: 18754744
references.citation: Trends Pharmacol Sci. 2001 Jan;22(1):5-7
references.pmid: 11261415
references.citation: J Clin Invest. 1996 Feb 1;97(3):713-9
references.pmid: 8609227
references.citation: J Physiol. 2002 Dec 15;545(3):869-78
references.pmid: 12482892
references.citation: Biochem Biophys Res Commun. 1991 Mar 15;175(2):637-44
references.pmid: 1850250
references.citation: J Vasc Res. 2009;46(5):447-58
references.pmid: 19155635
references.citation: Cell Host Microbe. 2008 Sep 11;4(3):198-208
references.pmid: 18779046
references.citation: Blood. 2001 Feb 1;97(3):587-600
references.pmid: 11157473
references.citation: Proc Natl Acad Sci U S A. 1997 Feb 4;94(3):831-6
references.pmid: 9023342
references.citation: Biochim Biophys Acta. 2003 May 20;1638(1):1-19
references.pmid: 12757929