FIG. 1.
The in vitro effects of rhPDGF-BB on AdBMP2-transfected BMSCs. (A) Effects of rhPDGF-BB treatment for 48 h on the proliferation of AdBMP2-transfected BMSCs (5×103 cells/well). The cell proliferation of both nontransfected BMSCs and AdBMP2-transfected BMSCs was significantly increased by the rhPDGF-BB treatment at days 3 and 7 (ANOVA, p<0.001 and p<0.001, respectively). (B) The amount of BMP-2 produced by AdBMP2-transfected BMSCs (1×104 cells/well), as determined by ELISA. Although BMP-2 was overexpressed over a 21-day period in AdBMP2-transfected BMSCs, BMP-2 expression was significantly decreased after 21 days compared to the initial levels (ANOVA, p<0.001). Furthermore, the rhPDGF-BB treatment did not significantly influence BMP-2 expression at each interval. (C) Effects of rhPDGF-BB on ALP (1×104 cells/well). The ALP activity was significantly increased by BMP2 gene delivery, which was suppressed by the rhPDGF-BB treatment for 48 h after 7 and 14 days (ANOVA, p<0.001 and p<0.001, respectively). (D) Effects of rhPDGF-BB on the mineralization of AdBMP2-transfected BMSCs (1×104 cells/well). AdBMP2-transfected BMSCs formed mineralization nodules at day 7, which was significantly suppressed by the rhPDGF-BB treatment for 48 h (ANOVA, p=0.001). *Statistically significant difference from the BMSCs and AdBMP-2-trasnfected BMSCs at day 3. †Statistically significant difference from the BMSCs and AdBMP-2-trasnfected BMSCs at day 7. ‡Statistically significant difference from the other groups. #Statistically significant difference from the other groups. Values represent mean±SD of three samples. OD, optical density. BMP-2, bone morphogenetic protein-2; BMSC, bone marrow stromal cell; ALP, alkaline phosphatase; ANOVA, analysis of variance; PDGF-BB, platelet-derived growth factor-BB; AdBMP-2, adenoviral vector containing the BMP2 gene. Color images available online at www.liebertpub.com/tea