Effects of Canonical NF-κB Signaling Pathway on the Proliferation and Odonto/Osteogenic Differentiation of Human Stem Cells from Apical Papilla

Background Information. NF-kappa B signaling pathway plays a complicated role in the biological functions of mesenchymal stem cells. However, the effects of NF-kappa B pathway on the odonto/osteogenic differentiation of stem cells from apical papilla (SCAPs) remain unclear. The present study was designed to evaluate the effects of canonical NF-kappa B pathway on the osteo/odontogenic capacity of SCAPs in vitro. Results. Western blot results demonstrated that NF-kappa B pathway in SCAPs was successfully activated by TNF-alpha or blocked by BMS-345541. NF-kappa B pathway-activated SCAPs presented a higher proliferation activity compared with control groups, as indicated by dimethyl-thiazol-diphenyl tetrazoliumbromide assay (MTT) and flowcytometry assay (FCM). Wound scratch assay revealed that NF-kappa B pathway-activated SCAPs presented an improved migration capacity, enhanced alkaline phosphatase (ALP) activity, and upregulated mineralization capacity of SCAPs, as compared with control groups. Meanwhile, the odonto/osteogenic markers (ALP/ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, OPN/OPN, BSP/BSP, DSPP/DSP, and DMP-1/DMP-1) in NF-kappa B pathway-activated SCAPs were also significantly upregulated as compared with control groups at both protein and mRNA levels. However, NF-kappa B pathway-inhibited SCAPs exhibited a lower proliferation/migration capacity, and decreased odonto/osteogenic ability in comparison with control groups. Conclusion. Our findings suggest that classical NF-kappa B pathway plays a paramount role in the proliferation and committed differentiation of SCAPs.