Abstract:Aim To explore the role of Notch signaling pathway in platelet derived growth factor-AA (PDGF-AA) induced vascular smooth muscle cell (VSMC) proliferation and migration. Methods 1-2 months old Sprague Dawley (SD) male rats were used in present study. Rat abdominal aorta was gained by aseptic operation, after removing the outer membrane of vascular and the endothelium, smooth muscle cells (SMC) was acquired by block pasting method and identified by immunofluorescence assay for α-SM-actin staining. The experiment was divided into four groups:normal group (Control), γ-secretase inhibitor group (DAPT), PDGF-AA group (PDGF-AA), PDGF-AA combined γ-secretase group (PDGF-AA+DAPT). The expression of Jagged1, Jagged2, Notch1-4, HES1, HEY1 and HEY2 mRNA was detected by real-time quantitative polymerase chain reaction (real-time qPCR), cell proliferation activity was detected by CellTiter96 Aqueous One Solution kit, and the migration of SMC was detected by cell scratching assay. Results Notch signals including Jagged1, Jagged 2, and Notch1-3 were expressed in cultured SMC. PDGF-AA induced increased Jagged 2 mRNA expression 24 h post-stimulation ( P<0.01,n=4) and increased Jagged1 mRNA expression 48 h post-stimulation (P<0.01, n=4); Notch1 and 3 mRNA expression also significantly increased 72 h after PDGF-AA stimulation compared with 0 h group (P<0.01, n=4), whereas Notch2 mRNA were obviously decreased by PDGF-AA 48 h post-stimulation (P<0.01, n=4). PDGF-AA also significantly promoted the HES1 (P<0.05,n=4), HEY2 (P<0.05, n=4) and transcription factor Rbp-j kappa (P<0.05, n=4) mRNA expression in SMC, DAPT markedly inhibited PDGF-AA induced HES1, HEY2 mRNA expression (P<0.01, n=4), but DAPT further increased PDGF-AA induced Rbp-j kappa mRNA expression (P<0.05, n=4); PDGF-AA stimulation obviously promoted SMC proliferation (P<0.01, n=5) and reduced remaining scratches area (P<0.01, n=4), whereas the effects were significantly attenuated by DAPT (P<0.01,n=4). Conclusions PDGF-AA can directly affect the expressions of Notch signaling molecules in SMC, Notch signaling pathway is partly in responsible for PDGF-AA-induced SMC proliferation and migration.
