TY - JOUR
T1 - GPR40 is a low-affinity epoxyeicosatrienoic acid receptor in vascular cells
AU - Park, Sang Kyu
AU - Herrnreiter, Anja
AU - Pfister, Sandra L.
AU - Gauthier, Kathryn M.
AU - Falck, Benjamin A.
AU - Falck, J R
AU - Campbell, William B.
N1 - Publisher Copyright:
© 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2018/7/6
Y1 - 2018/7/6
N2 - Endothelium-derived epoxyeicosatrienoic acids (EETs) have numerous vascular activities mediated by G protein–coupled receptors. Long-chain free fatty acids and EETs activate GPR40, prompting us to investigate the role of GPR40 in some vascular EET activities. 14,15-EET, 11,12-EET, arachidonic acid, and the GPR40 agonist GW9508 increase intracellular calcium concentrations in human GPR40 – overexpressing HEK293 cells (EC50 0.58 0.08 M, 0.91 0.08 M, 3.9 0.06 M, and 19 0.37 nM, respectively). EETs with cis- and trans-epoxides had similar activities, whereas substitution of a thiirane sulfur for the epoxide oxygen decreased the activities. 8,9-EET, 5,6-EET, and the epoxide hydrolysis products 11,12- and 14,15-dihydroxyeico-satrienoic acids were less active than 11,12-EET. The GPR40 antagonist GW1100 and siRNA-mediated GPR40 silencing blocked the EET- and GW9508-induced calcium increases. EETs are weak GPR120 agonists. GPR40 expression was detected in human and bovine endothelial cells (ECs), smooth muscle cells, and arteries. 11,12-EET concentration-dependently relaxed preconstricted coronary arteries; however, these relaxations were not altered by GW1100. In human ECs, 11,12-EET increased MAP kinase (MAPK)-mediated ERK phosphorylation, phosphorylation and levels of connexin-43 (Cx43), and expression of cyclooxygenase-2 (COX-2), all of which were inhibited by GW1100 and the MAPK inhibitor U0126. Moreover, siRNA-mediated GPR40 silencing decreased 11,12-EET–induced ERK phosphorylation. These results indicated that GPR40 is a low-affinity EET receptor in vascular cells and arteries. We conclude that epoxidation of arachidonic acid to EETs enhances GPR40 agonist activity and that 11,12-EET stimulation of GPR40 increases Cx43 and COX-2 expression in ECs via ERK phosphorylation.
AB - Endothelium-derived epoxyeicosatrienoic acids (EETs) have numerous vascular activities mediated by G protein–coupled receptors. Long-chain free fatty acids and EETs activate GPR40, prompting us to investigate the role of GPR40 in some vascular EET activities. 14,15-EET, 11,12-EET, arachidonic acid, and the GPR40 agonist GW9508 increase intracellular calcium concentrations in human GPR40 – overexpressing HEK293 cells (EC50 0.58 0.08 M, 0.91 0.08 M, 3.9 0.06 M, and 19 0.37 nM, respectively). EETs with cis- and trans-epoxides had similar activities, whereas substitution of a thiirane sulfur for the epoxide oxygen decreased the activities. 8,9-EET, 5,6-EET, and the epoxide hydrolysis products 11,12- and 14,15-dihydroxyeico-satrienoic acids were less active than 11,12-EET. The GPR40 antagonist GW1100 and siRNA-mediated GPR40 silencing blocked the EET- and GW9508-induced calcium increases. EETs are weak GPR120 agonists. GPR40 expression was detected in human and bovine endothelial cells (ECs), smooth muscle cells, and arteries. 11,12-EET concentration-dependently relaxed preconstricted coronary arteries; however, these relaxations were not altered by GW1100. In human ECs, 11,12-EET increased MAP kinase (MAPK)-mediated ERK phosphorylation, phosphorylation and levels of connexin-43 (Cx43), and expression of cyclooxygenase-2 (COX-2), all of which were inhibited by GW1100 and the MAPK inhibitor U0126. Moreover, siRNA-mediated GPR40 silencing decreased 11,12-EET–induced ERK phosphorylation. These results indicated that GPR40 is a low-affinity EET receptor in vascular cells and arteries. We conclude that epoxidation of arachidonic acid to EETs enhances GPR40 agonist activity and that 11,12-EET stimulation of GPR40 increases Cx43 and COX-2 expression in ECs via ERK phosphorylation.
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U2 - 10.1074/jbc.RA117.001297
DO - 10.1074/jbc.RA117.001297
M3 - Article
C2 - 29777058
AN - SCOPUS:85049468178
SN - 0021-9258
VL - 293
SP - 10675
EP - 10691
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 27
ER -