Osteogenic differentiation of MDSCs. A (a and b), the cell before was induced of the induced group and the control group; d, f and h, the control group of osteogenic differentiation, after 1d, 7d, and 14d, and were also negative for alizarin red staining; c, the induced group of osteogenic differentiation. After induction for 14 days, the cells became confluent and formed mineralized nodules and alizarin red staining was positive(bar=100μm); e and g, the cells before and after of induced group, the alizarin red staining was positive (bar=25μm). B, RT-PCR detection of the osteogenic markers OPN, ALP and COLI expression. 1, marker; 2, GAPDH; 3, OPN+; 4, OPN- (MDSCs); 5, ALP+; 6, ALP- (MDSCs); 7, COLI+; 8, COLI- (MDSCs).