Effects of siRNA-AdipoR1 transfection on the differentiation of MC3T3-E1 cells. Total RNA was collected at 4, 7, 10 days after siRNA-AdipoR1 transfection. Col-I (A) and OCN (B) mRNA expression were decreased by blocking the receptor expression. Results are expressed as fold increase over the control values at 4 days. The result was the representative of five different experiments. (C) ALP activity of siRNA-AdipoR1-transfected MC3T3-E1 cells. ALP activity was evaluated biochemically. ALP activity was significantly decreased compared to the control (*** p < 0.001).