Fig. 8

BMP9 enhances osteogenic differentiation of synovial cells by promoting ALP activity and the formation of mineralized nodules. (1) Successful BMP9 Transfection (A): BMP9 expression was observed under a fluorescence microscope. Cells in the BMP9 group exhibited bright green fluorescence, indicating successful and efficient transfection. (2) BMP9 Significantly Promotes ALP Activity (B, C, G): ALP staining at 3 and 5 days showed that the BMP9-treated group had significantly higher ALP expression compared to the control and GFP groups. Quantitative analysis revealed that ALP activity was significantly increased in the BMP9 group on both day 3 and day 5, with statistical significance (*p < 0.05). (3) BMP9 Promotes Mineral Nodule Formation: ARS staining at 7 and 14 days showed that the BMP9 group exhibited a more widespread distribution of mineralized nodules with a darker color, indicating significantly enhanced mineralization (D, E). ARS absorbance measurements showed that the BMP9 group had significantly higher mineralization levels at both day 7 and day 14 compared to the control and GFP groups, with statistical significance (*p < 0.05, F)