RT Journal Article SR Electronic T1 Prostaglandin E2 Derived from Cyclooxygenases 1 and 2 Mediates Intestinal Epithelial Ion Transport Stimulated by the Activation of Protease-Activated Receptor 2 JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 747 OP 752 DO 10.1124/jpet.108.145466 VO 329 IS 2 A1 Jacques Q. van der Merwe A1 Christina L. Ohland A1 Christina L. Hirota A1 Wallace K. MacNaughton YR 2009 UL http://jpet.aspetjournals.org/content/329/2/747.abstract AB Proteinase-activated receptor (PAR)2 is activated by trypsin-like serine proteinases and has been implicated in intestinal inflammation. However, its role in the regulation of intestinal mucosal function remains unclear. Using the intestinal epithelial cell line, SCBN, we have studied the stimulus-secretion coupling mechanisms of PAR2-induced epithelial chloride transport, focusing on cyclooxygenase (COX)-1 and COX-2 activities and prostaglandin (PG) E2 secretion. SCBN monolayers were grown on Snapwell supports, mounted in modified Ussing chambers, and exposed to the activating peptide, SLIGRL-NH2 (50 μM), to activate PAR2. Pretreatment with inhibitors of cytosolic PLA2 (cPLA2) (AACOCF3, arachidonyltrifluoromethyl ketone), COX-1 [SC560, 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole], and COX-2 (celecoxib) resulted in a significant concentration-dependent attenuation of PAR2-induced changes in short-circuit current. Immunoblot analysis showed a PAR2-induced increase in cPLA2 phosphorylation that was blocked by the mitogen-activated protein kinase kinase inhibitor, PD98059 [2-(2-amino-3methoxyphenyl)-4H-1benzopyran-4-one, C16H13NO3], and the pan-protein kinase C inhibitor, GFX (bisindolylmaleimide). PAR2 stimulation also resulted in a large increase in the production of PGE2 as determined by enzyme-linked immunosorbent assay and was also blocked by PD98059 and GFX. Immunofluorescence and immunoblot analysis determined that EP2 and EP4 are expressed at the basolateral membrane of SCBN cells. Through the use of selective inhibitors (EP2, AH6809 [6-isopropoxy-9-oxoxanthene-2-carboxylic acid]; EP4, GW627368X [N-{2[4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl] acetyl}benzene sulphonamide]), it was found that both EP2 and EP4 were involved in mediating the PAR2-induced chloride secretory response. We conclude that basolateral PAR2 activation induces epithelial chloride secretion that is mediated by cPLA2, COX-1, COX-2, and the subsequent release of PGE2. The production of PGE2 results in an autocrine secretory response that is dependent on basolateral EP2 and EP4 receptors. The American Society for Pharmacology and Experimental Therapeutics