Effects of different pulp-capping materials on cell death signaling pathways of lipoteichoic acid-stimulated human dental pulp stem cells.

Abstract

This study aimed to evaluate the response of dental pulp stem cells (DPSCs) cultured with and without lipoteichoic acid (LTA) to different pulp-capping materials. The cells were cultured and seeded in 6-well plates and exposed to 1% LTA solution. Dycal, ProRoot MTA and Biodentine materials were applied on cells and all groups were evaluated by cell proliferation, viability, cell cycle and cell death signaling pathways for 24 and 72h. LTA + Dycal treatment significantly inhibited the proliferation of DPSCs and increased the apoptosis rate of cells more than the other groups at 72h. Compared to other groups, LTA + Dycal treatment significantly increased the levels of Caspase-3 and AKT and decreased the levels of p-AKT. The results of this study revealed that all tested materials caused apoptosis in DPSCs via an extrinsic apoptotic pathway. The DPSCs showed an early apoptosis response to the Dycal and a late apoptosis response to the ProRoot MTA and Biodentine treatments. LTA led autophagy and inhibited the proliferation of DPSCs. ProRoot MTA and Biodentin eliminated the LTA's bioactivity with higher efficiency than Dycal.