TY - JOUR A1 - Tunaru, Sorin A1 - Chennupati, Ramesh A1 - Nüsing, Rolf M. A1 - Offermanns, Stefan T1 - Arachidonic acid metabolite 19(S)-HETE induces vasorelaxation and platelet inhibition by activating prostacyclin (IP) receptor T2 - PLoS one N2 - 19(S)-hydroxy-eicosatetraenoic acid (19(S)-HETE) belongs to a family of arachidonic acid metabolites produced by cytochrome P450 enzymes, which play critical roles in the regulation of cardiovascular, renal and pulmonary functions. Although it has been known for a long time that 19(S)-HETE has vascular effects, its mechanism of action has remained unclear. In this study we show that 19(S)-HETE induces cAMP accumulation in the human megakaryoblastic leukemia cell line MEG-01. This effect was concentration-dependent with an EC50 of 520 nM, insensitive to pharmacological inhibition of COX-1/2 and required the expression of the G-protein Gs. Systematic siRNA-mediated knock-down of each G-protein coupled receptor (GPCR) expressed in MEG-01 followed by functional analysis identified the prostacyclin receptor (IP) as the mediator of the effects of 19(S)-HETE, and the heterologously expressed IP receptor was also activated by 19(S)-HETE in a concentration-dependent manner with an EC50 of 567 nM. Pretreatment of isolated murine platelets with 19(S)-HETE blocked thrombin-induced platelets aggregation, an effect not seen in platelets from mice lacking the IP receptor. Furthermore, 19(S)-HETE was able to relax mouse mesenteric artery- and thoracic aorta-derived vessel segments. While pharmacological inhibition of COX-1/2 enzymes had no effect on the vasodilatory activity of 19(S)-HETE these effects were not observed in vessels from mice lacking the IP receptor. These results identify a novel mechanism of action for the CYP450-dependent arachidonic acid metabolite 19(S)-HETE and point to the existence of a broader spectrum of naturally occurring prostanoid receptor agonists. Y1 - 2016 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/41579 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-415790 UR - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5035018 SN - 1932-6203 N1 - Copyright: © 2016 Tunaru et al. This is an open access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. VL - 11 IS - (9):e0163633 SP - 1 EP - 16 PB - PLoS CY - Lawrence, Kan. ER -