Eicosanoid regulation of vascular endothelial growth factor expression and angiogenesis in microvessel endothelial cells.
12(R)-Hydroxy-5,8,14-eicosatrienoic acid (HETrE) is a potent inflammatory and angiogenic eicosanoid in ocular and dermal tissues. Previous studies suggested that 12(R)-HETrE activates microvessel endothelial cells via a high affinity binding site; however, the cellular mechanisms underlying 12(R)-HETrE angiogenic activity are unexplored. Because the synthesis of 12(R)-HETrE is induced in response to hypoxic injury, we examined its interactions with vascular endothelial growth factor (VEGF) in rabbit limbal microvessel endothelial cells. Addition of 12(R)-HETrE (0.1 nm) to the cells increased VEGF mRNA levels with maximum 5-fold increase at 45 min. The increase in VEGF mRNA was followed by an increase in immunoreactive VEGF protein. 12(R)-HETrE (0.1 nm) rapidly activated the extracellular signal-regulated kinases (ERKs) ERK1 and ERK2. Moreover, preincubation of cells with PD98059, a selective inhibitor of MEK-1, inhibited 12(R)-HETrE-induced VEGF mRNA. Addition of VEGF antibody to cells grown in Matrigel-coated culture plates inhibited 12(R)-HETrE-induced capillary tube-like formation, suggesting that VEGF mediates, at least in part, the angiogenic response to 12(R)-HETrE. The results indicate that in microvessel endothelial cells, 12(R)-HETrE induces VEGF expression via activation of ERK1/2 and that VEGF mediates, at least in part, the angiogenic activity of 12(R)-HETrE. Given the fact that both VEGF and 12(R)-HETrE are produced in the cornea after hypoxic injury, their interaction may be an important determinant in the development of neovascularized tissues.
Mezentsev
Alexander
A
Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA.
Seta
Francesca
F
Dunn
Michael W
MW
Ono
Naoya
N
Falck
John R
JR
Laniado-Schwartzman
Michal
M
D000818:Animals; D002478:Cells, Cultured; D015777:Eicosanoids / Q000502:physiology*; D016228:Endothelial Growth Factors / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D008222:Lymphokines / Q000235:genetics*; D020935:MAP Kinase Signaling System; D011817:Rabbits; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D015777:Eicosanoids; D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors