title: Dynamic modulation of interendothelial gap junctional communication by 11,12-epoxyeicosatrienoic acid.
abstract: Functional gap junctional communication between vascular cells has been implicated in ascending dilatation and the cytochrome P-450 (CYP) inhibitor-sensitive and NO- and prostacyclin-independent dilatation of many vascular beds. Here, we assessed the mechanisms by which the epoxyeicosatrienoic acids (EETs) generated by a CYP 2C enzyme control interendothelial gap junctional communication. In CYP 2C-expressing porcine coronary endothelial cells, bradykinin, which enhances EET formation, elicited a biphasic effect on the electrical coupling and transfer of Lucifer yellow between endothelial cells, consisting of a transient increase in coupling followed by a sustained uncoupling. The initial phase was sensitive to the CYP 2C9 inhibitor sulfaphenazole and the protein kinase A (PKA) inhibitors Rp-cAMPS and KT5720 and could be mimicked by forskolin and caged cAMP as well as by the PKA activators 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole 3',5'-cyclic monophosphorothioate sodium salt and Sp-cAMPS. Gap junction uncoupling in bradykinin-stimulated porcine coronary endothelial cells was prevented by inhibiting the activation of extracellular signal-regulated kinase (ERK)1/2. In human endothelial cells, which express little CYP 2C, bradykinin elicited only an ERK1/2-mediated inhibition of intercellular communication. The CYP 2C9 product, 11,12-EET, also exerted a dual effect on the electrical and dye coupling of human endothelial cells, which was sensitive to PKA inhibition. These results demonstrate that an agonist-activated CYP-dependent pathway as well as 11,12-EET can positively regulate interendothelial gap junctional communication, most probably via the activation of PKA, an effect that is curtailed by the subsequent activation of ERK1/2.
authors.affiliation: Institut für Kardiovaskuläre Physiologie, Klinikum der J.W.G.-Universität, Frankfurt am Main, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Popp
authors.forename: Ralf P
authors.initials: RP
authors.lastname: Brandes
authors.forename: Gregor
authors.initials: G
authors.lastname: Ott
authors.forename: Rudi
authors.initials: R
authors.lastname: Busse
authors.forename: Ingrid
authors.initials: I
authors.lastname: Fleming
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D001692:Biological Transport / Q000187:drug effects; D001920:Bradykinin / Q000494:pharmacology; D002450:Cell Communication / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D018031:Connexin 43 / Q000378:metabolism; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000187:drug effects / Q000378:metabolism; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007546:Isoquinolines / Q000493:pharmacokinetics; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D039181:Steroid 16-alpha-Hydroxylase; D013250:Steroid Hydroxylases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C089981:(2-nitrophenyl)ethyl-cyclic adenosine monophosphate; D018031:Connexin 43; D065607:Cytochrome P-450 Enzyme Inhibitors; D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007546:Isoquinolines; D012333:RNA, Messenger; D014665:Vasodilator Agents; D005576:Colforsin; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid; D003577:Cytochrome P-450 Enzyme System; C017475:lucifer yellow; D000242:Cyclic AMP; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; D039181:Steroid 16-alpha-Hydroxylase; D017868:Cyclic AMP-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D015126:8,11,14-Eicosatrienoic Acid; D001920:Bradykinin