hBMP-7 induces the differentiation of adipose-derived mesenchymal stem cells into osteoblast-like cells

The aim of this study was to investigate the differentiation potential of adipose-derived mesenchymal stem cells (ADMSCs) into osteoblasts by human bone morphogenetic protein-7 (hBMP-7) induction. ADMSCs were isolated from the subcutaneous adipose tissue of a rabbit, and then transfected with the pcDNA3.1 vector alone and pcDNA3.1-hBMP-7 (hBMP-7), respectively. Untransfected ADMSCs were used as the control group. After transfection, the morphology and green fluorescent protein (GFP) fluorescence intensity of ADMSCs were observed by fluorescent microscopy. The 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the growth of ADMSCs at 1, 3, and 5 days, respectively. Transmission electron microscopy was performed to observe the ultrastructural morphology of ADMSCs. In addition, ADMSCs were stained with quinalizarin and toluidine blue to reflect the content of osteoblasts and chondrocytes, respectively. Finally, the expression of collagen I and osteocalcin in ADMSCs was detected by western blot. ADMSCs were successfully isolated. Obvious GFP fluorescence and high expression of hBMP-7 demonstrated the successful transfection of hBMP-7. Specific morphological characters with a metabolically active ultrastructure were exhibited on the ADMSCs transfected with hBMP- 7. In addition, the growth rate of ADMSCs transfected with hBMP-7 was significantly higher than that of the cells in the vector and control groups. Successfully induced osteoblast-like cells were identified by an obvious erythrine area and high expression of collagen I and osteocalcin in ADMSCs transfected with hBMP-7. Thus, ADMSCs can be successfully differentiated into osteoblast-like cells by hBMP-7 induction in vitro.