Effects of and transgenes on the osteogenic potential of bone marrow stromal cells in vitro and in vivo

An exogenous supply of growth factors and bioreplaceable scaffolds may help bone regeneration. The aim of this study was to examine the effects of TGF-β1 and VEGF-A transgenes on the osteogenic potential of bone marrow stromal cells. Rat bone marrow stromal cells were transfected with plasmids encoding mouse TGF-β1 and/or VEGF-A complementary DNAs and cultured for up to 28 days. Furthermore, collagen scaffolds carrying combinations of the plasmids-transfected cells were implanted subcutaneously in rats. The transgenes increased alkaline phosphatase activity, enhanced mineralized nodule formation, and elevated osteogenic gene expressions in vitro. In vivo, messenger RNA expression of osteogenic genes such as BMP s and Runx2 elevated higher by the transgenes. The data indicate that exogenous TGF-β1 and VEGF-A acted synergistically and could induce osteoblastic differentiation of bone marrow stromal cells in both cell culture and an animal model. The results may provide valuable information to optimize protocols for transgene-and-cell-based tissue engineering.