Figure 2.

Effects of activin A on osteoblastic differentiation of Saos2 cells (A,B) Saos2 cells were cultured with 0.5 mM CaCl₂ with or without activin A (5, 10, 50 or 100 ng/mL) for 3 weeks. Mineralization of Saos2 cells was evaluated by Alizarin Red S staining (AR) and von Kossa staining (VK), and quantification of the staining area was analyzed. (C) Expression of the genes encoding OCN, OPN, and RUNX2 was analyzed using quantitative reverse transcription polymerase chain reaction (RT-PCR) in Saos2 cells cultured under the same conditions. Normalization of gene expression was performed against β-actin expression, and the results were evaluated as the fold increase of the control. Values are the means ± SD from three independent experiments. * p < 0.05, ** p < 0.01.