BRF1 triggers autophagy in pulp stem cells and inflamed pulp tissues

Abstract

Abstract Objective Nowadays post-transcriptional modifications play a key role in autophagy regulation. There is a lack of studies on dental pulp disease however. In this study we explored the effect of BRF1 on autophagy in inflamed pulp tissue and human dental pulp stem cells (hDPSCs). Methods The expressions of BRF1, autophagy and dentinogenic markers in normal and inflamed pulp were examined by immunohistochemical analysis. The presence of autophagosomes was confirmed by transmission electron microscopy. Then primary hDPSCs were incubated with 1 µg/mL lipopolysaccharide (LPS) for different time periods. The expression of BRF1 and autophagy makers were evaluated by western blotting. BRF1 knockdown and 3MA treatment was applied to detect the level changes of autophagy and dentinogenic differentiation. Double immunofluorescence assessment was performed to co-localize BRF1 with LC3B in pulp tissue. Results The expressions of BRF1, LC3, DMP1 and DSP were remarkably increased in inflamed pulp. LPS enhanced the protein productions of IL-6, BRF1, LC3 and Beclin-1 from 6h to 24h. BRF1 knockdown reduced the ratio of LC3-II/LC3-I and differentiation ability of hDPSCs, while 3MA attenuated LPS-mediated dentinogenic differentiation. Double-labeling analysis revealed co-localization of BRF1 with LC3B in inflamed pulp. Conclusion Our data indicated that BRF1 played a positive role in autophagy activation and might facilitate repair function during pulpitis.