Novel vasocontractile role of the P2Y14receptor: characterization of its signalling in porcine isolated pancreatic arteries

Alsaqati, M.; Latif, M.L.; Chan, S.L.F.; Ralevic, V.

Abstract

Background and Purpose: The P2Y14 receptor is the newest member of the P2Y receptor family; it is Gi/o protein-coupled and is activated by UDP and selectively by UDP-glucose and MRS2690 (2-thiouridine-5′-diphosphoglucose) (7–10-fold more potent than UDP-glucose). This study investigated whether P2Y14 receptors were functionally expressed in porcine isolated pancreatic arteries.
Experimental Approach: Pancreatic arteries were prepared for isometric tension recording and UDP-glucose, UDP and MRS2690 were applied cumulatively after preconstriction with U46619, a TxA2 mimetic. Levels of phosphorylated myosin light chain 2 (MLC2) were assessed with Western blotting. cAMP concentrations were assessed using a competitive enzyme immunoassay kit.
Key Results: Concentration-dependent contractions with a rank order of potency of MRS2690 (10-fold) > UDP-glucose ≥ UDP were recorded. These contractions were reduced by PPTN {4-[4-(piperidin-4-yl)phenyl]-7-[4-(trifluoromethyl)phenyl]-2-naphthoic acid}, a selective antagonist of P2Y14 receptors, which did not affect responses to UTP. Contraction to UDP-glucose was not affected by MRS2578, a P2Y6 receptor selective antagonist. Raising cAMP levels and forskolin, in the presence of U46619, enhanced contractions to UDP-glucose. In addition, UDP-glucose and MRS2690 inhibited forskolin-stimulated cAMP levels. Removal of the endothelium and inhibition of endothelium-derived contractile agents (TxA2, PGF2α and endothelin-1) inhibited contractions to UDP glucose. Y-27632, nifedipine and thapsigargin also reduced contractions to the agonists. UDP-glucose and MRS2690 increased MLC2 phosphorylation, which was blocked by PPTN.
Conclusions and Implications: P2Y14 receptors play a novel vasocontractile role in porcine pancreatic arteries, mediating contraction via cAMP-dependent mechanisms, elevation of intracellular Ca2+ levels, activation of RhoA/ROCK signalling and MLC2, along with release of TxA2, PGF2α and endothelin-1.

• Journal Article Type: Article
• Acceptance Date: Oct 9, 2013
• Online Publication Date: Jan 13, 2014
• Publication Date: Feb 4, 2014
• Deposit Date: Jul 11, 2016
• Publicly Available Date: Jul 11, 2016
• Journal: British Journal of Pharmacology
• Print ISSN: 0007-1188
• Electronic ISSN: 0007-1188
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 171
• Issue: 3
• DOI: https://doi.org/10.1111/bph.12473
• Keywords: UDP-glucose; UDP;MRS2690; P2Y14 receptor; vasoconstriction; endothelium
• Public URL: https://nottingham-repository.worktribe.com/output/723538
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1111/bph.12473/abstract;jsessionid=804DA88F606FEAA0EC72BFAE4C608687.f01t02
• Additional Information: This is the peer reviewed version of the following article: Alsaqati, M., Latif, M. L., Chan, S. L. F. and Ralevic, V. (2014), Novel vasocontractile role of the P2Y14 receptor: characterization of its signalling in porcine isolated pancreatic arteries. British Journal of Pharmacology, 171: 701–713. doi: 10.1111/bph.12473, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/bph.12473. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.