GPR40 is a low-affinity epoxyeicosatrienoic acid receptor in vascular cells

Sang Kyu Park, Anja Herrnreiter, Sandra L. Pfister, Kathryn M. Gauthier, Benjamin A. Falck, J R Falck, William B. Campbell

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

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.

Original languageEnglish (US)
Pages (from-to)10675-10691
Number of pages17
JournalJournal of Biological Chemistry
Volume293
Issue number27
DOIs
StatePublished - Jul 6 2018

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'GPR40 is a low-affinity epoxyeicosatrienoic acid receptor in vascular cells'. Together they form a unique fingerprint.

  • Cite this

    Park, S. K., Herrnreiter, A., Pfister, S. L., Gauthier, K. M., Falck, B. A., Falck, J. R., & Campbell, W. B. (2018). GPR40 is a low-affinity epoxyeicosatrienoic acid receptor in vascular cells. Journal of Biological Chemistry, 293(27), 10675-10691. https://doi.org/10.1074/jbc.RA117.001297