This Article Full Text Full Text (PDF) Data Supplement All Versions of this Article: 27/12/2612    most recent ATVBAHA.107.152074v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fleming, I. Articles by Busse, R. Search for Related Content PubMed PubMed Citation Articles by Fleming, I. Articles by Busse, R. Related Collections Related Article

(Arteriosclerosis, Thrombosis, and Vascular Biology. 2007;27:2612.)
© 2007 American Heart Association, Inc.

Vascular Biology

Epoxyeicosatrienoic Acids Regulate Trp Channel–Dependent Ca²⁺ Signaling and Hyperpolarization in Endothelial Cells

Ingrid Fleming; Alexandra Rueben; Rüdiger Popp; Beate Fisslthaler; Susanne Schrodt; Anna Sander; Judith Haendeler; John R. Falck; Christophe Morisseau; Bruce D. Hammock; Rudi Busse

From the Vascular Signaling Group, Institut für Kardiovaskuläre Physiologie (I.F., A.R., R.P., B.F., S.S., A.S., R.B.), and Molecular Cardiology (J.H.), Department of Internal Medicine III, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany; the Department of Biochemistry (J.R.F.), University of Texas Southwestern Medical Center, Dallas; and the Department of Entomology (C.M., B.D.H.), University of California, Davis.

Correspondence to Ingrid Fleming, PhD, Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany. E-mail fleming{at}em.uni-frankfurt.de

Objective— An initial step in endothelium-derived hyperpolarizing factor-mediated responses is endothelial cell hyperpolarization. Here we address the mechanisms by which cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) contribute to this effect in native and cultured endothelial cells.

Methods and Results— In native CYP2C-expressing endothelial cells, bradykinin elicited a Ca²⁺ influx that was potentiated by the soluble epoxide hydrolase inhibitor, 1-adamantyl-3-cyclohexylurea (ACU), and attenuated by CYP inhibition. Similar effects were observed in cultured endothelial cells overexpressing CYP2C9, but not in CYP2C9-deficient cells, and were prevented by the EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid as well as by the cAMP antagonist, Rp-cAMPS. The effects on Ca²⁺ were mirrored by prolongation of the bradykinin-induced hyperpolarization. Ruthenium red and the combination of charybdotoxin and apamin prevented the latter effect, suggesting that Trp channel activation increases Ca²⁺ influx and prolongs the activation of Ca²⁺-dependent K⁺ (K_Ca) channels. Indeed, overexpression of CYP2C9 enhanced the agonist-induced translocation of a TrpC6-V5 fusion protein to caveolin-1–rich areas of the endothelial cell membrane, which was prevented by Rp-cAMPS and mimicked by 11,12-EET.

Conclusions— Elevated EET levels regulate Ca²⁺ influx into endothelial cells and the subsequent activation of K_Ca channels, via a cAMP/PKA-dependent mechanism that involves the intracellular translocation of Trp channels.

Bradykinin-induced Ca²⁺ influx and Ca²⁺-dependent K⁺ channel activation in endothelial cells is potentiated by cytochrome P450 (CYP) expression and soluble epoxide hydrolase (sEH) inhibition. An epoxyeicosatrienoic acid-induced translocation of a TrpC6-V5 fusion protein to the endothelial cell membrane via a cAMP-dependent mechanism can account for these findings.

Key Words: caveolae • cytochrome P450 • endothelium-derived hyperpolarizing factor • protein kinase A

Related Article:

Epoxyeicosatrienoic Acids, TRP Channels, and Intracellular Ca²⁺ in the Vasculature: An Endothelium-Derived Endothelium-Hyperpolarizing Factor?

Brandon T. Larsen, David X. Zhang, and David D. Gutterman
Arterioscler Thromb Vasc Biol 2007 27: 2496-2498. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

				S. Earley, T. Pauyo, R. Drapp, M. J. Tavares, W. Liedtke, and J. E. Brayden TRPV4-dependent dilation of peripheral resistance arteries influences arterial pressure Am J Physiol Heart Circ Physiol, September 1, 2009; 297(3): H1096 - H1102. [Abstract] [Full Text] [PDF]

				R. Inoue, L. J. Jensen, Z. Jian, J. Shi, L. Hai, A. I. Lurie, F. H. Henriksen, M. Salomonsson, H. Morita, Y. Kawarabayashi, et al. Synergistic Activation of Vascular TRPC6 Channel by Receptor and Mechanical Stimulation via Phospholipase C/Diacylglycerol and Phospholipase A2/{omega}-Hydroxylase/20-HETE Pathways Circ. Res., June 19, 2009; 104(12): 1399 - 1409. [Abstract] [Full Text] [PDF]

				A. A. Spector Arachidonic acid cytochrome P450 epoxygenase pathway J. Lipid Res., April 1, 2009; 50(Supplement): S52 - S56. [Abstract] [Full Text] [PDF]

				M. K. Cathcart Signal-activated phospholipase regulation of leukocyte chemotaxis J. Lipid Res., April 1, 2009; 50(Supplement): S231 - S236. [Abstract] [Full Text] [PDF]

				P. Sun, W. Liu, D.-H. Lin, P. Yue, R. Kemp, L. M. Satlin, and W.-H. Wang Epoxyeicosatrienoic Acid Activates BK Channels in the Cortical Collecting Duct J. Am. Soc. Nephrol., March 1, 2009; 20(3): 513 - 523. [Abstract] [Full Text] [PDF]

				R.-W. Guo, H. Wang, P. Gao, M.-Q. Li, C.-Y. Zeng, Y. Yu, J.-F. Chen, M.-B. Song, Y.-K. Shi, and L. Huang An essential role for stromal interaction molecule 1 in neointima formation following arterial injury Cardiovasc Res, March 1, 2009; 81(4): 660 - 668. [Abstract] [Full Text] [PDF]

				D. X. Zhang, S. A. Mendoza, A. H. Bubolz, A. Mizuno, Z.-D. Ge, R. Li, D. C. Warltier, M. Suzuki, and D. D. Gutterman Transient Receptor Potential Vanilloid Type 4-Deficient Mice Exhibit Impaired Endothelium-Dependent Relaxation Induced by Acetylcholine In Vitro and In Vivo Hypertension, March 1, 2009; 53(3): 532 - 538. [Abstract] [Full Text] [PDF]

				J. Abramowitz and L. Birnbaumer Physiology and pathophysiology of canonical transient receptor potential channels FASEB J, February 1, 2009; 23(2): 297 - 328. [Abstract] [Full Text] [PDF]

				B. Keseru, E. Barbosa-Sicard, R. Popp, B. Fisslthaler, A. Dietrich, T. Gudermann, B. D. Hammock, J. R. Falck, N. Weissmann, R. Busse, et al. Epoxyeicosatrienoic acids and the soluble epoxide hydrolase are determinants of pulmonary artery pressure and the acute hypoxic pulmonary vasoconstrictor response FASEB J, December 1, 2008; 22(12): 4306 - 4315. [Abstract] [Full Text] [PDF]

				A. E. Loot, R. Popp, B. Fisslthaler, J. Vriens, B. Nilius, and I. Fleming Role of cytochrome P450-dependent transient receptor potential V4 activation in flow-induced vasodilatation Cardiovasc Res, December 1, 2008; 80(3): 445 - 452. [Abstract] [Full Text] [PDF]

				A. C. Webler, U. R. Michaelis, R. Popp, E. Barbosa-Sicard, A. Murugan, J. R. Falck, B. Fisslthaler, and I. Fleming Epoxyeicosatrienoic acids are part of the VEGF-activated signaling cascade leading to angiogenesis Am J Physiol Cell Physiol, November 1, 2008; 295(5): C1292 - C1301. [Abstract] [Full Text] [PDF]

				J.-K. Chen, J. Chen, J. D. Imig, S. Wei, D. L. Hachey, J. S. Guthi, J. R. Falck, J. H. Capdevila, and R. C. Harris Identification of Novel Endogenous Cytochrome P450 Arachidonate Metabolites with High Affinity for Cannabinoid Receptors J. Biol. Chem., September 5, 2008; 283(36): 24514 - 24524. [Abstract] [Full Text] [PDF]

				J. Saliez, C. Bouzin, G. Rath, P. Ghisdal, F. Desjardins, R. Rezzani, L.F. Rodella, J. Vriens, B. Nilius, O. Feron, et al. Role of Caveolar Compartmentation in Endothelium-Derived Hyperpolarizing Factor-Mediated Relaxation: Ca2+ Signals and Gap Junction Function Are Regulated by Caveolin in Endothelial Cells Circulation, February 26, 2008; 117(8): 1065 - 1074. [Abstract] [Full Text] [PDF]

				B. T. Larsen, D. X. Zhang, and D. D. Gutterman Epoxyeicosatrienoic Acids, TRP Channels, and Intracellular Ca2+ in the Vasculature: An Endothelium-Derived Endothelium-Hyperpolarizing Factor? Arterioscler Thromb Vasc Biol, December 1, 2007; 27(12): 2496 - 2498. [Full Text] [PDF]