Fig. 6.

E. coli-produced DMP1 increased the mRNA expression of osteogenic markers. The hPDL cells were treated with 0.5 μg/ml, 1 μg/ml and 2 μg/ml E. coli-produced DMP1 for 72 h. Total RNA was extracted, and real-time PCR was performed using primer sets for human ALP, BMP2, CBFA1, COL1, OPN, OSX, and WNT3a genes. The values obtained for nontreated cells were set at 1 for subsequent fold change calculation. Cells treated with the proteins purified from E. coli without the DMP1 gene using the same protocol as DMP1 purification served as the negative control. The data are shown as the mean ± SD, derived from triplicate experiments. Means with three asterisks (***) are significantly different (P < 0.01).