title: Lung inflammation caused by adenosine-5'-triphosphate is mediated via Ca2+/PKCs-dependent COX-2/PGE2 induction.
abstract: Up-regulation of cyclooxygenase (COX)-2 and prostaglandin E2 (PGE2) are implicated in lung inflammation. Adenosine 5'-triphosphate (ATP) has been shown to act via activation of P2 purinoceptors, leading to COX-2 expression in various inflammatory diseases. The mechanisms of ATP-induced COX-2 expression and PGE2 release remain unclear. We showed that pretreatment with the inhibitors of P2 receptors (PPADS and Suramin), Gq protein (GPA2A), phosphatidylcholine-phospholipase C (PC-PLC; D609), phosphoinositide-phospholipase C (PI-PLC; ET-18-OCH3), Ca(2+)/calmodulin-dependent protein kinase II (CaMKII; KN62), protein kinase C (PKC; Gö6976, Ro-318220, GF109203X, and rottlerin), MEK1/2 (PD98059), p38 MAPK (SB202190), and nuclear factor-kappaB (NF-κB; Bay11-7082) and the intracellular calcium chelator (BAPTA/AM) or transfection with siRNAs of these molecules and cPLA2 reduced ATPγS-induced COX-2 expression or PGE2 production in A549 cells. In addition, ATPγS-induced elevation of intracellular Ca(2+) concentration was attenuated by PPADS, Suramin, D609, or ET-18-OCH3. ATPγS-induced p38 MAPK, p42/p44 MAPK, and NF-κB p65 activation were inhibited by Gö6976, Ro-318220, GF109203X, or rottlerin. ATPγS also induced cPLA2 phosphorylation and activity, which were reduced via inhibition of P2 receptors, PKCs, p38 MAPK, and p42/p44 MAPK. ATPγS-induced cPLA2 expression was inhibited by SB202190, PD98059, or Bay11-7082. In the in vitro study, we established that ATPγS induced PGE2 generation via a cPLA2/COX-2-dependent pathway. In the in vivo study, we found that ATPγS induced COX-2 mRNA expression in the lungs and leukocyte (mainly eosinophils and neutrophils) count in bronchoalveolar lavage (BAL) fluid in mice via a P2 receptors-dependent signaling pathway. We concluded that ATPγS may induce lung inflammation via a cPLA2/COX-2/PGE2-dependent pathway.
authors.affiliation: Department of Anesthetics, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors.forename: I-Ta
authors.initials: IT
authors.lastname: Lee
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Lin
authors.forename: Wei-Ning
authors.initials: WN
authors.lastname: Lin
authors.forename: Wan-Ling
authors.initials: WL
authors.lastname: Wu
authors.forename: Li-Der
authors.initials: LD
authors.lastname: Hsiao
authors.forename: Chuen-Mao
authors.initials: CM
authors.lastname: Yang
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000235:genetics; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015232:Dinoprostone / Q000096:biosynthesis*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D054510:Phospholipases A2, Cytosolic / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D016328:NF-kappa B; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011493:Protein Kinase C; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D019950:Mitogen-Activated Protein Kinase 1; D048051:p38 Mitogen-Activated Protein Kinases; D054510:Phospholipases A2, Cytosolic; D010738:Type C Phospholipases; D015232:Dinoprostone; D002118:Calcium
keywords: Cyclooxygenase-2; Cytosolic phospholipase A(2); Inflammation; Lung injury; Transcription factor