title: Prostaglandin E(2) upregulates cyclooxygenase-2 expression in lipopolysaccharide-stimulated RAW 264.7 macrophages.
abstract: Prostaglandin E(2) (PGE(2)) has been implicated in the regulation of inflammatory and immunological events. Using RAW 264.7 macrophages, the present study investigates the influence of PGE(2) on the expression of cyclooxygenase-2 (COX-2). Incubation of cells with PGE(2) increased lipopolysaccharide (LPS)-induced COX-2 mRNA levels in a concentration-dependent manner. Upregulation of COX-2 expression by PGE(2) was completely abolished by the specific adenylyl cyclase inhibitor 2',5'-dideoxyadenosine and mimicked by butaprost, a selective agonist of the adenylyl cyclase-coupled PGE(2) receptor subtype 2 (EP(2)), or 11-deoxy PGE(1), an EP(2)/EP(4) receptor agonist. By contrast, the EP(3)/EP(1) receptor agonists 17-phenyl-omega-trinor PGE(2) and sulprostone left LPS-induced COX-2 expression virtually unaltered. Upregulation of LPS-induced COX-2 expression and subsequent PGE(2) synthesis was also observed in the presence of the cell-permeable cAMP analogue dibutyryl cAMP and the adenylyl cyclase activator cholera toxin. Together, our data demonstrate that PGE(2) potentiates COX-2 mRNA expression via an adenylyl cyclase/cAMP-dependent pathway. In conclusion, upregulation of COX-2 expression via an autocrine feed-forward loop may in part contribute to the well-known capacity of PGE(2)/cAMP to modulate inflammatory processes.
authors.affiliation: Department of Experimental and Clinical Pharmacology and Toxicology, Friedrich Alexander University Erlangen-Nürnberg, Germany. hinz@pharmakologie.uni-erlangen.de
authors.forename: B
authors.initials: B
authors.lastname: Hinz
authors.forename: K
authors.initials: K
authors.lastname: Brune
authors.forename: A
authors.initials: A
authors.lastname: Pahl
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects* / Q000235:genetics; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018078:Receptors, Prostaglandin E / Q000819:agonists / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D007527:Isoenzymes; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D018078:Receptors, Prostaglandin E; D003994:Bucladesine; D002772:Cholera Toxin; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D000262:Adenylyl Cyclases; D015232:Dinoprostone