Piezo1 Promotes Osteogenesis Through CaMKII Signalling in a Rat Maxillary Expansion Model.

Objectives: Rapid maxillary expansion (RME) is a widely used technique to treat maxillary transverse deficiency. Piezo1 is a cation channel that is activated by mechanical force and regulates bone formation. This study aims to elucidate the role of Piezo1 in bone remodelling during the RME process.

Materials and methods: In this study, the periosteal-derived stem cells (PDSCs) were cultured and stretched by the Flexcell system. The effects of Piezo1 on osteogenesis were assessed via RNA sequencing, real-time quantitative PCR, and western blot analyses. Moreover, for in vivo analyses, the rat RME model was established. The function of Piezo1 in mid-palatal suture bone remodelling was evaluated using micro-CT, haematoxylin-eosin (HE) staining, and immunohistochemistry analyses.

Results: It was revealed that under tension force, the osteogenic factors (Runt-related transcription factor 2, Osterix, and Alkaline Phosphatase) and Ca²⁺/calmodulin -dependent protein kinase (CaMKII) were significantly enhanced in PDSCs over time. Furthermore, these were also upregulated in the RME model with the expansion of the mid-palatal suture. However, Piezo1 inhibition by Grammostola spatulata mechanotoxin 4 downregulated the levels of these factors in the RME model.

Conclusions: This study indicated that Piezo1 is associated with the osteogenesis of PDSCs and bone remodelling in the RME process. CaMKII might also participate in this process.