Yes-associated protein promotes bone healing after tooth extraction in mice

In this study, a tooth extraction socket model was established in vivo, and Lv-YAP1-GFP, Lv-GFP or saline was injected locally into the extraction socket. Expression of markers of osteogenesis, osteoclastogenesis, adipogenesis, proliferation and apoptosis explore whether YAP can promote bone formation in the process of tooth extraction socket healing. 66 BALB/c mice were divided into 3 groups and underwent left maxillary first molar extraction, Lv-YAP1-GFP, Lv-GFP or saline was injected into the tooth extraction socket. The maxilla was harvested 1, 3, 7, and 10 days after operation for subsequent analysis by Micro-CT and immunohistochemical analysis. Quantitative analysis of the expression of TRAP, ALP, BMP2, RUNX2, Osterix, OCN, RANKL, PPARγ, and PCNA was conducted. The results of immunofluorescence showed that the lentivirus was successfully transfected into the extraction socket. On the middle and last stage of tooth extraction healing, results of Micro-CT showed that the BV/TV, Tb.Th and Tb.N were significantly higher in the experimental group, results of immunohistochemistry showed that the overexpression of YAP increase in the expression of BMP2, ALP, RUNX2, Osterix, OCN, and PCNA. The expression of PPARγ and TUNEL staining results were significantly lower in the experimental group. The expression of TRAP and RANKL showed no significant differences among the 3 groups. We conclude that YAP could promote bone formation in the middle and late stages of tooth extraction socket healing. The overexpression of YAP increased bone formation and cell proliferation, decreased adipogenic differentiation and apoptosis.