大鼠正畸牙移动压力侧牙槽骨中cath K mRNA表达的研究

Expression of cathepsin K mRNA in alveolar bone on the pressure side during tooth movement in rats

目的研究组织蛋白酶K(cathepsin K,cath K)mRNA在大鼠正畸牙移动压力侧牙槽骨中的表达变化及时间分布特点,探讨正畸牙移动中牙周改建的分子生物学机制。方法选用80只6周龄SD雄性大鼠建立正畸牙移动模型,分别在加力后2d、5d、7d、10d和14d处死动物各16只,HE染色观察牙周组织改建的变化,TRAP染色计数压力侧破骨细胞数量;实时定量PCR(real-time quantitative PCR)检测cath K mRNA表达变化及时间分布特点。结果cath K mRNA表达随加力时间的增加而增加,在加力后的第7天开始下降。这与牙周组织形态学的变化以及TRAP染色阳性破骨细胞数目的变化规律相一致。结论在生物机械力的诱导下,cathK参与了正畸牙移动骨改建过程中有机基质的降解,cath K mRNA随正畸加力时间的增加出现规律性变化。

Objective To investigate the expression of cathepsin K mRNA in alveolar bone on the pressure side in rats during experimental tooth movement and to elucidate the molecular changes and mechanism of orthodontic tooth movement.Methods An experimental model of orthodontic tooth movement was established in 80 6-week-old male SD rats which were sacrificed at 2,5,7,10 and 14 days after orthodontic force application.The morphological changes were observed by HE staining.The numbers of TRAP-positive osteoclasts in alveolar bone on the pressure side were counted.The mRNA expression of cath K was quantified by real-time quantitative PCR.Results Remarked increase in cath K mRNA was found after orthodontic force application and cath K mRNA decreased at 7-14 days.The change tendency of cath K mRNA was consistent with the change of bone remodeling and the number of TRAP-positive osteoclasts.Conclusion Cath K participated in proteolysis during orthodontic tooth movement and cath K mRNA changed with time of orthodontic force application.