Creatine promotes osteogenic differentiation of dental pulp stem cells via the AMPK-ULK1-autophagy axis.

Objective: We aimed to demonstrate the effects of creatine (Cr) on osteogenic differentiation (OD) in HDPSCs.

Materials and methods: HDPSCs were treated with Cr and an inhibitor of Cr transporter. The OD capacity was evaluated by detecting ALP staining and activity, alizarin red staining (ARS), as well as osteogenesis-related protein levels. Transcriptomic sequencing, western blotting, transmission electron microscopy, immunofluorescence staining, and autophagy-related protein marker detection were applied to illustrate the underlying mechanism. Furthermore, the impact of Cr on bone regeneration was investigated in vivo.

Results: We found that 1 mm of Cr effectively enhanced the OD of HDPSCs. The creatine group displayed significantly increased AMPK phosphorylation, overexpressed autophagy-related proteins, enhanced OD, and mineralization capabilities. We also found that ULK1 is the downstream molecule through which AMPK induces cellular autophagy. In vivo results demonstrated that Cr could increase the new bone formation of periodontitis.

Conclusion: Our research discovered a new AMPK-ULK1-autophagy pathway through which Cr enhances OD in HDPSCs. Cr enhanced HDPSCs-mediated periodontal tissue regeneration in a periodontitis mouse model, providing a theoretical foundation for the study of bone repair in periodontitis.