Abstract: Objective To investigate the influence of minocycline on osteogenic differentiation of rat dental pulp stem cells (RDPSCs) and the effect on Wnt/β-Catenin pathway. Methods RDPSCs were randomly divided into control group and minocycline groups with different concentrations (0.1, 1.0, 10.0, 100.0 mg/L), and osteogenic differentiation was induced. CCK-8 method was used to detect the cell proliferation rate; the kit was used to detect alkaline phosphatase (ALP) and osteocalcin (OCN); alizarin red S staining was used to detect calcium deposition; qRT-PCR was used to detect ALP and OCN mRNA expression; Western blot (WB) was used to detect protein expression levels of β-Catenin, glycogen synthase kinase-3β (GSK-3β) and Runt related transcription factor 2 (Runx2). Results Compared with those in the control group, the proliferation rate, activity of ALP, content of OCN, calcium deposition, protein levels of β-Catenin and Runx2 were significantly increased in 0.1 and 1.0 mg/L minocycline groups; the protein level of GSK-3β was significantly decreased (all P＜0.05). The proliferation rate of RDPSCs in 10.0, 100.0 mg/L minocycline groups was significantly increased (P>0.05); activity of ALP, content of OCN and their expression levels, calcium deposition, protein levels of β-Catenin and Runx2 were significantly decreased; the protein level of GSK-3β was significantly increased (all P＜0.05). Conclusion Low-concentration minocycline can induce osteogenic differentiation of rat dental pulp stem cells, while high-concentration minocycline can inhibit osteogenic differentiation of rat dental pulp stem cells, which may be achieved by regulating Wnt/β-Catenin signaling pathway.

Key words: minocycline, Wnt/β-Catenin pathway, dental pulp stem cells, osteogenic differentiation, alkaline phosphatase