Comparative analysis of differentiation capacity between tumor necrosis factor-alpha (TNF-α)-treated and untreated dental pulp stems (DPCs). TNF-α treatment induced a great deposition of calcified matrix as detected by alizarin red staining and alkaline phosphatase (A) as well as the mRNA levels of DSPP, ALP, OPN, and OCN (B). Increased adipogenic differential ability was also observed in TNF-α-treated DPCs, determined by staining with oil red O and increase in mRNA levels of AP2 (C). *P <0.05, ***P <0.001, unpaired t test. Data are representative of three independent experiments. Scale bar = 100 μm.