Prostaglandin E2 regulates angiogenesis via activation of fibroblast growth factor receptor-1.
Prostaglandin E(2) (PGE(2)) behaves as a mitogen in epithelial tumor cells as well as in many other cell types. We investigated the actions of PGE(2) on microvascular endothelial cells (capillary venular endothelial cells) with the purpose of delineating the signaling pathway leading to the acquisition of the angiogenic phenotype and to new vessel formation. PGE(2) (100 nM) produced activation of the fibroblast growth factor receptor 1 (FGFR-1), as measured by its phosphorylation, but not of vascular endothelial growth factor receptor 2. PGE(2) stimulated the EP3 subtype receptor, as deduced by abrogation of EP3 Galpha(i) subunit activity through pertussis toxin. Consistent with this result, in human umbilical venular endothelial cells missing the EP3 receptor, PGE(2) did not phosphorylate FGFR-1. Upon binding to its receptor, PGE(2) initiated an autocrine/paracrine signaling cascade involving the intracellular activation of c-Src, activation of matrix metalloproteinase (predominantly MMP2), which in turn caused the mobilization of membrane-anchored fibroblast growth factor-2 (FGF-2). In fact, in cells unable to release FGF-2 the transfection with both FGFR-1 and EP3 did not result in FGFR-1 phosphorylation in response to PGE(2). Relevance for the FGF2-FGFR-1 system was highlighted by confocal analysis, showing receptor internalization after cell exposure to the prostanoid. ERK1/2 appeared to be the distal signal involved, its phosphorylation being sensitive to either cSrc inhibitor or FGFR-1 blocker. Finally, PGE(2) stimulated cell migration and capillary formation in aortic rings, which were severely reduced by inhibitors of signaling molecules or by receptor antagonist. In conclusion, this study provides evidence for the involvement of FGFR-1 through FGF2 in eliciting PGE(2) angiogenic responses. This signaling pattern is similar to the autocrine-paracrine mechanism which operates in endothelial cells to support neovascular growth.
Department of Molecular Biology, University of Siena, Via Aldo Moro, 2, 53100 Siena, Italy.
Federica
F
Finetti
Raffaella
R
Solito
Lucia
L
Morbidelli
Antonio
A
Giachetti
Marina
M
Ziche
Sandra
S
Donnini
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology; D016466:CHO Cells; D002196:Capillaries / Q000166:cytology / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D006224:Cricetinae; D003412:Cricetulus; D015232:Dinoprostone / Q000378:metabolism / Q000494:pharmacology*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D044385:GTP-Binding Protein alpha Subunits / Q000378:metabolism; D016391:Genes, src / Q000502:physiology; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D010120:Oxytocics / Q000378:metabolism / Q000494:pharmacology*; D019899:Paracrine Communication / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism*; D018078:Receptors, Prostaglandin E / Q000378:metabolism; D058308:Receptors, Prostaglandin E, EP3 Subtype
D015232:Dinoprostone; D016222:Fibroblast Growth Factor 2; D044385:GTP-Binding Protein alpha Subunits; D020778:Matrix Metalloproteinase 2; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D010120:Oxytocics; D018719:Erb-b2 Receptor Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D018078:Receptors, Prostaglandin E; D058308:Receptors, Prostaglandin E, EP3 Subtype; C545647:PTGER3 protein, human; C545648:Ptger3 protein, mouse; C508053:ERBB2 protein, human; C496348:FGFR1 protein, human; C496349:Fgfr1 protein, mouse; C522361:MMP2 protein, human; C522362:Mmp2 protein, mouse