大鼠正畸牙移动压力侧牙槽骨中cath K、RANKL和OPG的表达

Expression of cath K,RANKL and OPG in alveolar bone on the pressure side during orthodontic tooth movement in rats

目的检测大鼠正畸牙移动压力侧cath K、RANKL和OPG蛋白表达变化及时间分布特点。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各处死16只大鼠。HE染色观察大鼠牙周组织的形态学变化;TRAP染色计数压力侧牙槽骨组织中的破骨细胞数量;免疫组化方法定位及相对定量检测压力侧牙槽骨中cath K、RANKL和OPG蛋白表达变化及时间分布特点。结果压力侧牙槽骨组织中的TRAP染色阳性破骨细胞计数随加力时间的增加而增加,第7d达到高峰,此后逐渐降低;压力侧牙槽骨组织中的cath K、RANKL和OPG蛋白的表达水平均随加力时间的增加而增加,第7d达到高峰,以后均逐渐降低。结论 cath K、RANKL和OPG蛋白表达的变化规律与骨改建过程一致,与正畸牙移动骨改建过程中破骨细胞的分化、形成和功能密切相关。

Objective To investigate the expression of cath K（cathepsin K）, RANKL（receptor activator nuclear factor kappa B ligand） and its decoy receptor, OPG （osteoprotegerin） in alveolar bone on the pressure side during orthodontic tooth movement. Methods An experimental model of orthodontic tooth movement was established in rats. The rats were executed 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. Cath K, RANKL and OPG protein expression were examined by immunohistochemistry. Results The number of TRAP-positive osteoclasts in alveolar bone on the pressure side significantly increased in a time-dependent manner at 2-7 days. After that the number of TRAP-positive osteoclasts in alveolar bone gradually decreased. The protein expression of cath K, RANKL and OPG in alveolar bone on the pressure side increased in a time-dependent manner after orthodontic force application. After that it gradually decreased at 7-14 days. Conclusion The expression of cath K, RANKL and OPG was consistent with the change of bone remodeling. Cath K, RANKL and OPG played an important role in the bone remodeling during orthodontic tooth movement.