Relationship between Wnt7a and Root Resorption by Experiments Tooth Movement in Cementoblast

抄録

Orthodontic root resorption（ORR）is an incident in orthodontic treatment. Previous, we reported that heavy orthodontic forces applied to cementoblast increased the development of apoptosis and root resorption. Wnt signaling is important for homeostasis and promotes differentiation of mesenchymal stem cells in the periodontal ligament into bone and cementum. Moreover, Wnt7a has involved in the apoptosis of chondrocytes, which are cementum-like cells. However, the relationship between the ORR, Wnt7a, and apoptosis of cementoblast is unknown. We examined the expression of Wnt7a, Caspase-3, and Dickkopf1（Dkk1）. Rats were divided 3 groups: Control, Optimal force（OF）, Heavy force（HF）. Then, the effects of the CF and Dkk1 on production were investigated using human cementoblast-like cells（HCEM）by real-time polymerase chain reaction（Real-time PCR）. Wnt7a-positive cells was significantly the most increased in the OF on days 5 and 7, and the Caspase-3-positive cells was significantly increased in the OF and HF. Dkk1-positive cells was significantly increased in OF and HF on day 3, and significantly increased in HF group on days 5 and 7. Compared to HF without Dkk1, Caspase-3 gene expression was significantly increased in HF with Dkk1 at 6 h and RANKL gene expression was significantly increased at 9 and 12 h. Wnt7a was highly expressed at OF, whereas Wnt7a decreased and Caspase-3 and Dkk1 increased at HF, suggesting that Caspase-3 were increased by Dkk1. Wnt7a is inhibited by Dkk1 and Caspase-3 is increased, resulting in apoptosis of cementoblast and increased ORR.