Fig. 3.

Production of MMPs in MTA-treated MC3T3-E1 cells. The cells were cultured in the absence or presence of MTA for 12 days. The medium was changed to serum-free conditioned medium. After 24 h, the conditioned medium was collected and concentrated. (A) MMP-9 was detected by gelatin-zymography as the precursor. (D) MMP-13 was detected by casein-zymography and western blotting as the precursor. A quantitative analysis of the intensity of each band was performed by Molecular Imager FX (Bio-Rad) (B and E). Total RNA was extracted and determined mRNA expression of Mmp9 (C) and Mmp13 (F) by real-time RT-PCR. Data represent the means ± SEM (n = 4). Statistical significance of differences between MTA treated group and corresponding time-matched vehicle control is indicated by *P < 0.05, **P < 0.01 and ***P < 0.001. Zymo, zymography; WB, western blotting.