DMOG increases the level and transcriptional activity of the Runx2 protein, leading to Dspp expression in MDPC-23 cells.

<p>(A) Runx2 knockdown suppresses DMOG stimulation of Dspp expression. The cells were transiently transfected with Runx2 siRNA or with control siRNA and incubated in the presence or absence of 1 mM DMOG for 48 h. The data are presented as the mean ± SD of triplicates. *Significantly different from control siRNA. ^#Significantly different from none-DMOG treated control (Student's t-test, <i>p</i><0.05). (B) Transcriptional activity of Runx2. The Runx2 reporter 6XOSE-Luc was transfected into MDPC-23 cells, and the cells were cultured for 48 h. Runx2 reporter luciferase activity was measured and normalized by Renilla luciferase activity. The data are presented as the mean ± SD (n = 6). *Significantly different from control (Student's t-test, <i>p</i><0.05). (C) The levels of Runx2 protein (upper) and transcripts (lower). (D) The cells were treated with 2 µM of MG132 for 24 h in the presence or absence of DMOG, and a western blot analysis was performed for Runx2. Western blot quantification was performed by measuring bands intensities, and the relative levels were normalized by β-actin.