Recombinant sFRP-2 suppresses ALP activity and mineralization induced by BMP-2 in MC3T3-E1 cells. MC3T3-E1 cells were cultured in the osteogenic medium. Recombinant mouse sFRP-2 was added at 1 μg/mL in the presence of rhBMP-2 (50 ng/mL). (A) Mineralized nodules were visualized at day 14 by von Kossa staining. (B) ALP activity was determined at day 10. Results are expressed as mean ± SEM of triplicate experiments. * indicates significantly different by Student t test, P < .05.