Objective: This study was designed to investigate the effects of mineral trioxide aggregate (MTA) on the osteo/odontogenic differentiation of inflammatory dental pulp stem cells (iDPSCs).
Materials and methods: inflammatory DPSCs were isolated from the inflammatory pulps of rat incisors and cocultured with MTA-conditioned medium. MTT assay and flow cytometry were performed to evaluate the proliferation of iDPSCs. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time RT-PCR, and Western blot assay were used to investigate the differentiation capacity as well as the involvement of NF-κB pathway in iDPSCs.
Results: Mineral trioxide aggregate-treated iDPSCs demonstrated the higher ALP activity and formed more mineralized nodules than the untreated group. The odonto/osteoblastic markers (Alp, Runx2/RUNX2, Osx/OSX, Ocn/OCN, and Dspp/DSP, respectively) in MTA-treated iDPSCs were significantly upregulated as compared with untreated iDPSCs. Mechanistically, cytoplastic phos-P65 and nuclear P65 in MTA-treated iDPSCs were significantly increased in a time-dependent manner. Moreover, the inhibition of NF-κB pathway suppressed the MTA-induced odonto/osteoblastic differentiation of iDPSCs, as indicated by decreased ALP levels, weakened mineralization capacity and downregulated levels of odonto/osteoblastic genes (Osx, Ocn, and Dspp).
Conclusions: Mineral trioxide aggregate enhances the odonto/osteogenic capacity of DPSCs from inflammatory sites via activating the NF-κB pathway.
Keywords: dental pulp stem cells; differentiation; inflammation; mineral trioxide aggregate; nuclear factor kappa B.
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.