title: Vascular endothelial growth factor (VEGF)-A165-induced prostacyclin synthesis requires the activation of VEGF receptor-1 and -2 heterodimer.
abstract: We previously reported that vascular endothelial growth factor (VEGF)-A(165) inflammatory effect is mediated by acute platelet-activating factor synthesis from endothelial cells upon the activation of VEGF receptor-2 (VEGFR-2) and its coreceptor, neuropilin-1 (NRP-1). In addition, VEGF-A(165) promotes the release of other endothelial mediators including nitric oxide and prostacyclin (PGI(2)). However, it is unknown whether VEGF-A(165) is mediating PGI(2) synthesis through VEGF receptor-1 (VEGFR-1) and/or VEGF receptor-2 (VEGFR-2) activation and whether the coreceptor NRP-1 potentiates VEGF-A(165) activity. In this study, PGI(2) synthesis in bovine aortic endothelial cells (BAEC) was assessed by quantifying its stable metabolite (6-keto prostaglandin F(1alpha), 6-keto PGF(1alpha)) by enzyme-linked immunosorbent assay. Treatment of BAEC with VEGF analogs, VEGF-A(165) (VEGFR-1, VEGFR-2 and NRP-1 agonist) and VEGF-A(121) (VEGFR-1 and VEGFR-2 agonist) (up to 10(-9) m), increased PGI(2) synthesis by 70- and 40-fold within 15 min. Treatment with VEGFR-1 (placental growth factor and VEGF-B) or VEGFR-2 (VEGF-C) agonist did not increase PGI(2) synthesis. The combination of VEGFR-1 and VEGFR-2 agonists did not increase PGI(2) release. Pretreatment with a VEGFR-2 inhibitor abrogated PGI(2) release mediated by VEGF-A(165) and VEGF-A(121), and pretreatment of BAEC with antisense oligomers targeting VEGFR-1 or VEGFR-2 mRNA reduced PGI(2) synthesis mediated by VEGF-A(165) and VEGF-A(121) up to 79%. In summary, our data demonstrate that the activation of VEGFR-1 and VEGFR-2 heterodimer (VEGFR-1/R-2) is essential for PGI(2) synthesis mediated by VEGF-A(165) and VEGF-A(121), which cannot be reproduced by the parallel activation of VEGFR-1 and VEGFR-2 homodimers with corresponding agonists. In addition, the binding of VEGF-A(165) to NRP-1 potentiates its capacity to promote PGI(2) synthesis.
authors.affiliation: Research Center, Montreal Heart Institute, Department of Pharmacology, Université de Montréal, 5000 Belanger St., Montreal, Quebec H1T 1C8, Canada.
authors.forename: Paul-Eduard
authors.initials: PE
authors.lastname: Neagoe
authors.forename: Caroline
authors.initials: C
authors.lastname: Lemieux
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sirois
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D015153:Blotting, Western; D002417:Cattle; D002478:Cells, Cultured; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D011464:Epoprostenol / Q000378:metabolism*; D005091:Exons; D005982:Glutathione Transferase / Q000378:metabolism; D008954:Models, Biological; D039942:Neuropilin-1 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000494:pharmacology; D010766:Phosphorylation; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism / Q000502:physiology*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D016376:Oligonucleotides, Antisense; D020033:Protein Isoforms; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D039942:Neuropilin-1; D009569:Nitric Oxide; D011464:Epoprostenol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D005982:Glutathione Transferase; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2