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GPR40 is a low-affinity epoxyeicosatrienoic acid receptor in vascular cells. J Biol Chem 2018 07 06;293(27):10675-10691 PMID: 29777058 PMCID: PMC6036206

Pubmed ID

29777058

DOI

10.1074/jbc.RA117.001297

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 (EC = 0.58 ± 0.08 μm, 0.91 ± 0.08 μm, 3.9 ± 0.06 μm, and 19 ± 0.37 nm, respectively). EETs with - and -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-dihydroxyeicosatrienoic 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.

Author List

Park SK, Herrnreiter A, Pfister SL, Gauthier KM, Falck BA, Falck JR, Campbell WB

Authors

William B. Campbell PhD Chair, Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin
Sandra L. Pfister PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin




Scopus

2-s2.0-85049468178   3 Citations

MESH terms used to index this publication - Major topics in bold

8,11,14-Eicosatrienoic Acid
Animals
Cattle
Endothelium, Vascular
Gene Expression Regulation
HEK293 Cells
Human Umbilical Vein Endothelial Cells
Humans
Patch-Clamp Techniques
Phosphorylation
Receptors, G-Protein-Coupled
Signal Transduction
jenkins-FCD Prod-353 9ccd8489072cb19f5b9f808bb23ed672c582f41e