This Article Full Text Full Text (PDF) Data Supplement All Versions of this Article: 28/6/1123    most recent ATVBAHA.107.161190v1 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 Webler, A. C. Articles by Fleming, I. Search for Related Content PubMed PubMed Citation Articles by Webler, A. C. Articles by Fleming, I.

(Arteriosclerosis, Thrombosis, and Vascular Biology. 2008;28:1123.)
© 2008 American Heart Association, Inc.

Integrative Physiology/Experimental Medicine

Cytochrome P450 2C9-Induced Angiogenesis Is Dependent on EphB4

Anke C. Webler; Rüdiger Popp; Thomas Korff; U. Ruth Michaelis; Carmen Urbich; Rudi Busse; Ingrid Fleming

From the Vascular Signalling Group (A.C.W., R.P., U.R.M., R.B., I.F.), Institut für Kardiovaskuläre Physiologie; and Molecular Cardiology (C.U.), Johann Wolfgang Goethe-Universität, Frankfurt; and the Institute of Physiology and Pathophysiology (T.K.), University Hospital Heidelberg, Germany.

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

Objective— Cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) are known to stimulate angiogenesis, but the mechanisms involved are incompletely understood. Because EphB4 is involved in vascular development, the aim of this study was to investigate whether, and to what extent, EphB4 is part of the signaling cascade that results in CYP2C9-mediated angiogenesis.

Methods and Results— CYP2C9 overexpression as well as stimulation with 11,12-EET (up to 48 hours) time-dependently increased EphB4 expression in endothelial cells. This effect and the activation of the EphB4 promoter were mediated by the phosphatidylinositol-3-kinase (P13-K)/Akt pathway and sensitive to the P13-K inhibitor LY 294002 as well as to simultaneous transfection with dominant-negative Akt. 11,12-EET treatment also increased EphB4 expression in isolated mouse mesenteric arteries as well as in the vessels that developed in 11,12-EET-impregnated Matrigel plugs. Moreover, the CYP2C9-stimulated formation of capillary-like structures in a modified spheroid assay was markedly attenuated by EphB4 downregulation (antisense oligonucleotides). Using a parallel approach in vivo, the inclusion of siRNA directed against EphB4 in EET-impregnated Matrigel plugs prevented endothelial cell invasion and vascularization.

Conclusions— Our data indicate that EphB4 is a critical component of the CYP2C9- and 11,12-EET-activated signaling cascade that promotes angiogenesis in vitro as well as in vivo.

Key Words: Akt • angiogenesis • epoxyeicosatrienoic acid • siRNA

This article has been cited by other articles:

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

				Y. Tang, E. A. Scheef, S. Wang, C. M. Sorenson, C. B. Marcus, C. R. Jefcoate, and N. Sheibani CYP1B1 expression promotes the proangiogenic phenotype of endothelium through decreased intracellular oxidative stress and thrombospondin-2 expression Blood, January 15, 2009; 113(3): 744 - 754. [Abstract] [Full Text] [PDF]