Tensile stress induced osteogenesis of periodontal ligament cells via Piezo1 mediated TAZ-Cbfα1 signaling.

Objective: Cyclic tensile stress (CTS) is known to induce osteogenesis of periodontal ligament cells (PDLCs), in which the molecular mechanism remains to be elucidated. This study aimed to investigate the role of the mechanosensitive calcium channel Piezo1 in the osteogenesis of PDLCs under tensile strain, as well as the signal regulation of the TAZ-Cbfα1 pathway in this process.

Design: PDLCs were isolated from periodontal ligament tissues and subjected to CTS. Alizarin red staining (ARS) and alkaline phosphatase (ALP) assay were used to detect the osteogenesis of PDLCs. RT-qPCR and Western blot were used to detect the transcripts and protein expression levels of Piezo1, Transcriptional co-activator with PDZ binding motif (TAZ), and Core-binding factor α1 (Cbfα1) respectively. Immunofluorescence staining was used to detect the nuclear aggregation of TAZ. Small interfering RNA (siRNA) targeting Piezo1 (Piezo1-siRNA) was adopted to inhibit Piezo1 mRNA expression.

Results: The results showed that the osteogenic differentiation capacity of PDLCs was significantly enhanced under CTS, along with elevated mRNA and protein expression levels of Piezo1, TAZ, and Cbfα1. Moreover, the ALP activity and the formation of calcium nodules by ARS staining were significantly increased. In addition, Piezo1 siRNA infection significantly inhibited the CTS-induced TAZ-Cbfα1 pathway and the osteogenesis of PDLCs, suggesting the regulatory role of Piezo1.

Conclusions: We provided evidence that the application of CTS encourages the osteogenic differentiation of PDLCs, which could be mediated by the Piezo1 targeted TAZ-Cbfα1 signaling.