title: Fibroblast growth factor-2 is a downstream mediator of phosphatidylinositol 3-kinase-Akt signaling in 14,15-epoxyeicosatrienoic acid-induced angiogenesis.
abstract: To determine the efficacy of cytochrome P450 2C9 metabolites of arachidonic acid, viz. 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs), in inducing angiogenesis, we have studied their effects on human dermal microvascular endothelial cell (HDMVEC) tube formation and migration. All four EETs stimulated HDMVEC tube formation and migration in a dose-dependent manner. Because 14,15-EET was found to be slightly more efficacious than 5,6-, 8,9-, and 11,12-EETs in stimulating HDMVEC tube formation and migration, we next focused on elucidation of the signaling mechanisms underlying its angiogenic activity. 14,15-EET stimulated Akt and S6K1 phosphorylation in Src- and phosphatidylinositol 3-kinase (PI3K)-dependent manner in HDMVECs. Inhibition of Src and PI3K-Akt-mTOR signaling by both pharmacological and dominant-negative mutant approaches suppressed 14,15-EET-induced HDMVEC tube formation and migration in vitro and Matrigel plug angiogenesis in vivo. In addition, 14,15-EET induced the expression of fibroblast growth factor-2 (FGF-2) in Src- and PI3K-Akt-dependent and mTOR-independent manner in HDMVECs. Neutralizing anti-FGF-2 antibodies completely suppressed 14,15-EET-induced HDMVEC tube formation and migration in vitro and Matrigel plug angiogenesis in vivo. Together, these results show for the first time that Src and PI3K-Akt signaling via targeting in parallel with FGF-2 expression and mTOR-S6K1 activation plays an indispensable role in 14,15-EET-induced angiogenesis.
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, 38163, USA.
authors.forename: Baolin
authors.initials: B
authors.lastname: Zhang
authors.forename: Huiqing
authors.initials: H
authors.lastname: Cao
authors.forename: Gadiparthi N
authors.initials: GN
authors.lastname: Rao
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002465:Cell Movement; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000166:cytology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000502:physiology*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D008833:Microcirculation; D009389:Neovascularization, Pathologic; D010100:Oxygen / Q000737:chemistry; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011509:Proteoglycans / Q000737:chemistry / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases
chemical_list: D015126:8,11,14-Eicosatrienoic Acid; D003094:Collagen; D004338:Drug Combinations; D016222:Fibroblast Growth Factor 2; D049452:Green Fluorescent Proteins; D007797:Laminin; D010100:Oxygen; D019869:Phosphatidylinositol 3-Kinases; D011494:Protein Kinases; D011509:Proteoglycans; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; C059485:matrigel; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid; C546842:MTOR protein, human; C546843:mTOR protein, mouse; C448959:ribosomal protein S6 kinase, 70kD, polypeptide 2