PDF(Pubmed)
Abstract：
BACKGROUND: The number of adult orthodontic patients is increasing, and studies have shown that autophagy is involved in regulating orthodontic tooth movement and plays an important role in aging-related changes. Therefore, we aimed to explore the role of autophagy in aging-related changes during orthodontic tooth movement by establishing a rat orthodontic tooth movement model.
METHODS: Forty-five 6-week-old and sixty-five 8-month-old male Sprague-Dawley rats were selected to represent adolescents and adults and establish orthodontic tooth movement model. They were sacrificed on days 0,1,3,7 and 14. Immunohistochemistry, immunofluorescence and tartrate resistant acid phosphatase (TRAP) staining were applied to measure the expression level of osteogenesis, autophagy, aging factors and osteoclast number in periodontal membrane of left upper first molar during orthodontic tooth movement. Then, we regulated the autophagy level by injecting autophagy activator rapamycin during orthodontic tooth movement and measured these factors and tooth movement distance by micro-computed tomography.
RESULTS: Aging factor levels in the periodontal membrane were higher in adult rats than in adolescent rats and the autophagy factor levels were lower. The levels of osteogenic factors were lower on the tension side in adult rats than in adolescent rats. The peak osteoclast number on the pressure side occurred later in adult rats than in adolescent rats. The injection of rapamycin increased autophagy, accelerated orthodontic tooth movement in adult rats, and reduced the levels of aging factors. The levels of osteogenic factors were higher and reached those in adolescent rats at some time points. The number of osteoclasts increased significantly in the early stage.
CONCLUSIONS: Autophagy may play a substantial role in regulating aging-related changes in orthodontic tooth movement.
METHODS: Forty-five 6-week-old and sixty-five 8-month-old male Sprague-Dawley rats were selected to represent adolescents and adults and establish orthodontic tooth movement model. They were sacrificed on days 0,1,3,7 and 14. Immunohistochemistry, immunofluorescence and tartrate resistant acid phosphatase (TRAP) staining were applied to measure the expression level of osteogenesis, autophagy, aging factors and osteoclast number in periodontal membrane of left upper first molar during orthodontic tooth movement. Then, we regulated the autophagy level by injecting autophagy activator rapamycin during orthodontic tooth movement and measured these factors and tooth movement distance by micro-computed tomography.
RESULTS: Aging factor levels in the periodontal membrane were higher in adult rats than in adolescent rats and the autophagy factor levels were lower. The levels of osteogenic factors were lower on the tension side in adult rats than in adolescent rats. The peak osteoclast number on the pressure side occurred later in adult rats than in adolescent rats. The injection of rapamycin increased autophagy, accelerated orthodontic tooth movement in adult rats, and reduced the levels of aging factors. The levels of osteogenic factors were higher and reached those in adolescent rats at some time points. The number of osteoclasts increased significantly in the early stage.
CONCLUSIONS: Autophagy may play a substantial role in regulating aging-related changes in orthodontic tooth movement.
摘要：
背景：成人正畸患者的数量正在增加，研究表明，自噬参与调节正畸牙齿移动，并在衰老相关的变化中起重要作用。因此,通过建立大鼠正畸牙齿移动模型，探讨自噬在正畸牙齿移动过程中衰老相关变化中的作用。
方法：选择45只6周龄和65只8月龄雄性Sprague-Dawley大鼠分别代表青少年和成人，建立正畸牙齿移动模型。他们在第0、1、3、7和14天被处死。免疫组织化学,免疫荧光和抗酒石酸酸性磷酸酶(TRAP)染色检测成骨的表达水平,自噬,正畸牙齿移动过程中左上第一磨牙牙周膜的衰老因素和破骨细胞数量。然后，我们通过在正畸牙齿移动过程中注射自噬激活剂雷帕霉素来调节自噬水平，并通过显微计算机断层扫描测量这些因素和牙齿移动距离。
结果：成年大鼠牙周膜衰老因子水平高于青春期大鼠，自噬因子水平较低。成骨因子的水平在成年大鼠的张力侧低于青春期大鼠。压力侧的破骨细胞峰值在成年大鼠中出现的时间晚于青春期大鼠。注射雷帕霉素增加自噬，加速成年大鼠的正畸牙齿移动，并降低了衰老因素的水平。成骨因子的水平较高，并在某些时间点达到青春期大鼠的水平。早期破骨细胞数量显著增加。
结论：自噬可能在调节正畸牙齿移动的老化相关变化中起重要作用。
方法：选择45只6周龄和65只8月龄雄性Sprague-Dawley大鼠分别代表青少年和成人，建立正畸牙齿移动模型。他们在第0、1、3、7和14天被处死。免疫组织化学,免疫荧光和抗酒石酸酸性磷酸酶(TRAP)染色检测成骨的表达水平,自噬,正畸牙齿移动过程中左上第一磨牙牙周膜的衰老因素和破骨细胞数量。然后，我们通过在正畸牙齿移动过程中注射自噬激活剂雷帕霉素来调节自噬水平，并通过显微计算机断层扫描测量这些因素和牙齿移动距离。
结果：成年大鼠牙周膜衰老因子水平高于青春期大鼠，自噬因子水平较低。成骨因子的水平在成年大鼠的张力侧低于青春期大鼠。压力侧的破骨细胞峰值在成年大鼠中出现的时间晚于青春期大鼠。注射雷帕霉素增加自噬，加速成年大鼠的正畸牙齿移动，并降低了衰老因素的水平。成骨因子的水平较高，并在某些时间点达到青春期大鼠的水平。早期破骨细胞数量显著增加。
结论：自噬可能在调节正畸牙齿移动的老化相关变化中起重要作用。
