LE-TDM induces hUCMSCs to differentiate into odontoblast-like cells in vitro. hUCMSCs induced by LE-TDM for 7 days; the LE-TDM-induced hUCMSCs grew well, and calcified areas were observed (arrow), but their morphology was similar to that of hUCMSCs (A). The effects of LE-TDM on the expression levels of DMP-1, DSPP, collagen I, and BMP-2 messenger RNA in hUCMSCs. The relative gene expression was normalized to the expression of GAPDH, and the control was set to 1.0. Values are expressed as the mean ± SD (**P < 0.01, ***P < 0.001) (B). Western blot assays showed that LE-TDM-induced hUCMSCs expressed DSP, collagen I, DSPP, DMP-1, and BMP-2, whereas hUCMSCs did not express these proteins (C). Values are expressed as the mean ± SD (*P < 0.05, ***P < 0.001) (D). hUCMSCs cultured in LE-TDM were positively stained for DSPP, but the control cells were not (E). The effects of LE-TDM on the MAPK signaling pathways for hUCMSCs. All cells were cultured for 60 min, and LE-TDM was added at 60, 30, 15, and 0 min, corresponding to the 0, 15, 30, and 60 min groups, respectively. The protein levels of ERK, p-ERK, P38, p-P38, JNK, and p-JNK were determined by western blot (F). Quantitative analysis of protein bands was done by ImageJ. The levels of p-JNK/JNK, p-P38/P38, and p-ERK/ERK were normalized by GAPDH (G).