title: Interleukin-1beta, transforming growth factor-beta1, and bradykinin attenuate cyclic AMP production by human pulmonary artery smooth muscle cells in response to prostacyclin analogues and prostaglandin E2 by cyclooxygenase-2 induction and downregulation of adenylyl cyclase isoforms 1, 2, and 4.
abstract: Increased levels of inflammatory cytokines contribute to the pathophysiology of pulmonary hypertension. Prostacyclin (PGI2) analogues, which relax pulmonary vessels mainly through cAMP elevation, have a major therapeutic role. In this study, we show that prolonged incubation with bradykinin (BK), interleukin-1beta (IL-1beta), and transforming growth factor-beta1 (TGF-beta1) markedly impairs cAMP accumulation in human pulmonary artery smooth muscle cells in response to short-term incubation with prostaglandin E2 (PGE2) and the PGI2 analogues iloprost and carbaprostacyclin. A similar reduction in cAMP accumulation in response to a direct adenylyl cyclase activator, forskolin, suggested that the effect was attributable to downregulation of adenylyl cyclase. Reverse transcriptase-polymerase chain reaction studies showed downregulation of adenylyl cyclase isoforms 1, 2, and 4. The effect of IL-1beta, BK, and TGF-beta1 on cAMP levels was abrogated by the selective COX-2 inhibitor NS398. Furthermore, it was mimicked by prolonged incubation with the COX-2 product PGE2 and PGI2 analogues or the COX substrate arachidonic acid, suggesting that it was mediated by endogenous prostanoids produced by COX-2. Consistent with this, IL-1beta, BK, and TGF-beta1 all induced COX-2 and PGE2 release. These results show that BK, IL-1beta, and TGF-beta1 downregulate adenylyl cyclase in human pulmonary artery smooth muscle cells via COX-2 induction and prostanoid release. This suggests a novel mechanism whereby mediators and cytokines produced in pulmonary hypertension may impair the therapeutic effects of prostacyclin analogues such as iloprost and carbaprostacyclin.
authors.affiliation: Division of Respiratory Medicine, University of Nottingham, City Hospital, Nottingham, UK.
authors.forename: H
authors.initials: H
authors.lastname: El-Haroun
authors.forename: D
authors.initials: D
authors.lastname: Bradbury
authors.forename: A
authors.initials: A
authors.lastname: Clayton
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Knox
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics* / Q000378:metabolism; D000328:Adult; D016718:Arachidonic Acid / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D011464:Epoprostenol / Q000031:analogs & derivatives / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis*; D007545:Isoproterenol / Q000494:pharmacology; D008565:Membrane Proteins; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D011453:Prostaglandins / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
chemical_list: D006133:Growth Substances; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D009578:Nitrobenzenes; D011453:Prostaglandins; D012333:RNA, Messenger; D013449:Sulfonamides; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D005576:Colforsin; D016718:Arachidonic Acid; D011464:Epoprostenol; D000242:Cyclic AMP; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1; C100622:adenylyl cyclase 2; C406262:adenylyl cyclase 4; D015232:Dinoprostone; D007545:Isoproterenol; D001920:Bradykinin