title: Stable EET urea agonist and soluble epoxide hydrolase inhibitor regulate rat pulmonary arteries through TRPCs.
abstract: Epoxyeicosatrienoic acids (EETs), cytochrome P450-derived metabolites of arachidonic acid, have been reported to increase intracellular calcium concentration in aortic vascular smooth muscle cells (SMCs). As EETs are labile, we synthesized a new stable urea EET analog with agonist and soluble epoxide hydrolase (sEH) inhibitor properties. We refer to this analog, 12-(3-hexylureido)dodec-8-enoic acid, as 8-HUDE. Measuring tension of vascular rings, intracellular calcium signaling by confocal laser scanning microscopy and gene expression by reverse-transcription-PCR and western blots, we examined the effects of 8-HUDE on pulmonary vascular tone and calcium signaling in rat pulmonary artery (PA) SMCs (PASMCs). 8-HUDE increased the tension of rat PAs to 145% baseline, whereas it had no effect on the tension of mesenteric arteries (MAs). The 8-HUDE-induced increase in vascular tone was abolished by removal of extracellular Ca(2+) or by pretreatment with either La(3+) or SKF96365, which are inhibitors of canonical transient receptor potential channels (TRPCs). Furthermore, 8-HUDE-evoked increases in [Ca(2+)](i) in PASMCs could be blunted by inhibition of TRPC with SKF96365, removal of extracellular calcium or depletion of intracellular calcium stores with caffeine, cyclopiazonic acid or 2-aminoethoxydiphenyl borate, but not by the voltage-activated calcium channel blocker nifedipine. In addition to immediate effects on calcium signaling, 8-HUDE upregulated the expression of TRPC1 and TRPC6 at both mRNA and protein levels in rat PASMCs, whereas it suppressed the expression of sEH. Our observations suggest that 8-HUDE increases PA vascular tone through increased release of calcium from intracellular stores, enhanced [Ca(2+)](i) influx in PASMCs through store-operated Ca(2+) channels and modulated the expression of TRPC and sEH proteins in a proconstrictive manner.
authors.affiliation: Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Ruifang
authors.initials: R
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Jingjing
authors.initials: J
authors.lastname: Rao
authors.forename: Weiyang
authors.initials: W
authors.lastname: Li
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.forename: Vijay L
authors.initials: VL
authors.lastname: Manthati
authors.forename: Meetha
authors.initials: M
authors.lastname: Medhora
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Jacobs
authors.forename: Daling
authors.initials: D
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004851:Epoxide Hydrolases / Q000037:antagonists & inhibitors*; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology*; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009543:Nifedipine / Q000494:pharmacology; D011651:Pulmonary Artery / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D050051:Transient Receptor Potential Channels / Q000037:antagonists & inhibitors*
chemical_list: C558427:12-(3-hexylureido)dodec-8(Z)-enoic acid; D001896:Boron Compounds; D002121:Calcium Channel Blockers; D004791:Enzyme Inhibitors; D005229:Fatty Acids, Monounsaturated; D007093:Imidazoles; D007211:Indoles; D050051:Transient Receptor Potential Channels; D002110:Caffeine; D007811:Lanthanum; C109986:2-aminoethoxydiphenyl borate; D004851:Epoxide Hydrolases; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D009543:Nifedipine; C000543:cyclopiazonic acid