The biological actions of 11,12-epoxyeicosatrienoic acid in endothelial cells are specific to the R/S-enantiomer and require the G(s) protein

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Item Type:	Article
Title:	The biological actions of 11,12-epoxyeicosatrienoic acid in endothelial cells are specific to the R/S-enantiomer and require the G(s) protein
Creators Name:	Ding, Y., Froemel, T., Popp, R., Falck, J.R., Schunck, W.H. and Fleming, I.
Abstract:	Cytochrome P450-derived epoxides of arachidonic acid [i.e., the epoxyeicosatrienoic acids (EETs)] are important lipid signaling molecules involved in the regulation of vascular tone and angiogenesis. Because many actions of 11,12-cis-epoxyeicosatrienoic acid (EET) are dependent on the activation of protein kinase A (PKA), the existence of a cell-surface G(s)-coupled receptor has been postulated. To assess whether the responses of endothelial cells to 11,12-EET are enantiomer specific and linked to a potential G protein-coupled receptor, we assessed 11,12-EET-induced, PKA-dependent translocation of transient receptor potential (TRP) C6 channels, as well as angiogenesis. In primary cultures of human endothelial cells, (+/-)-11,12-EET led to the rapid (30 seconds) translocation a TRPC6-V5 fusion protein, an effect reproduced by 11(R),12(S)-EET, but not by 11(S),12(R)-EET or (+/-)-14,15-EET. Similarly, endothelial cell migration and tube formation were stimulated by (+/-)-11,12-EET and 11(R),12(S)-EET, whereas 11(S),12(R)-EET and 11,12-dihydroxyeicosatrienoic acid were without effect. The effects of (+/-)-11,12-EET on TRP channel translocation and angiogenesis were sensitive to EET antagonists, and TRP channel trafficking was also prevented by a PKA inhibitor. The small interfering RNA-mediated downregulation of G(s) in endothelial cells had no significant effect on responses stimulated by vascular endothelial growth or a PKA activator but abolished responses to (+/-)-11,12-EET. The downregulation of G(q)/11 failed to prevent 11,12-EET-induced TRPC6 channel translocation or the formation of capillary-like structures. Taken together, our results suggest that a G(s)-coupled receptor in the endothelial cell membrane responds to 11(R),12(S)-EET and mediates the PKA-dependent translocation and activation of TRPC6 channels, as well as angiogenesis.
Keywords:	8,11,14-Eicosatrienoic Acid, Angiogenesis Inducing Agents, Cell Movement, Cyclic AMP-Dependent Protein Kinases, Down-Regulation, Gs GTP-Binding Protein alpha Subunits, Human Umbilical Vein Endothelial Cells, Primary Cell Culture, Small Interfering RNA, Stereoisomerism, TRPC Cation Channels, Vascular Endothelial Growth Factor A
Source:	Journal of Pharmacology and Experimental Therapeutics
ISSN:	0022-3565
Publisher:	American Society for Pharmacology and Experimental Therapeutics
Volume:	350
Number:	1
Page Range:	14-21
Date:	July 2014
Official Publication:	https://doi.org/10.1124/jpet.114.214254
PubMed:	View item in PubMed

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