title: Functional analysis of aortic endothelial cells expressing mutant PDGF receptors with respect to expression of matrix metalloproteinase-3.
abstract: Platelet-derived growth factor (PDGF) stimulates expression of matrix metalloproteinases (MMPs), including stromelysin-1 (MMP-3). Induction of these expressions is known to occur during the course of atherosclerosis, tumor invasion, and metastasis. We investigated PDGF-alpha receptor (alphaR)- and beta receptor (betaR)-mediated signaling pathways for the expression of MMP-3 and invasion activity using porcine aortic endothelial (PAE) cells with stable expression of normal or mutated PDGF receptors. RT-PCR and Western blot analyses revealed that PDGF-BB induces MMP-3 expression in PAE cells that exclusively express either the PDGF-alphaR or the -betaR, but not in non-transfected control cells. To identify the signals necessary for PDGF receptor-mediated induction of MMP-3 expression, several lines of PAE cells expressing mutant PDGF receptors were further analyzed. Cells expressing mutant PDGF receptors unable to associate with Src or PLCgamma, retained the ability to induce MMP-3 expression as a result of PDGF-BB stimulation. However, incubation with PDGF-BB did not induce MMP-3 expression in cells expressing a mutant PDGF-betaR unable to associate with phosphatidylinositol 3(')-kinase (PI3K). LY294002, a PI3K inhibitor, reduced PDGF-BB-stimulated MMP-3 expression in PAE cells expressing wild-type PDGF receptors. In contrast, PDGF-BB induced MMP-3 expression in the presence of U-73122, a PLCgamma inhibitor. Moreover, PDGF-BB enhanced the invasiveness of cells expressing wild type PDGF-beta receptors, but not of cells expressing mutant PDGF-betaRs impaired in their ability to associate with PI3K. In light of these results, it appears that PDGF-BB is capable of inducing MMP-3 expression through both the PDGF-alphaR and the -betaR, and the effects are contributed by the PI3K-mediated transduction pathways.
authors.affiliation: Department of Clinical Cell Biology (F5), Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Kanaki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Bujo
authors.forename: Seijiro
authors.initials: S
authors.lastname: Mori
authors.forename: Zhu
authors.initials: Z
authors.lastname: Yanjuan
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takahashi
authors.forename: Koutaro
authors.initials: K
authors.lastname: Yokote
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Morisaki
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Saito
mesh_terms: D000818:Animals; D001011:Aorta; D000077214:Becaplermin; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051966:Phospholipase C gamma; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000096:biosynthesis; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000096:biosynthesis / Q000235:genetics; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000096:biosynthesis / Q000235:genetics; D017479:Receptors, Platelet-Derived Growth Factor / Q000096:biosynthesis* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D013552:Swine; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D000077214:Becaplermin; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D019278:Matrix Metalloproteinase 3