不同正畸力对大鼠牙周组织压力侧辅助性T细胞17相关因子表达变化的影响

Effect of different orthodontic forces on the expression of T helper cell 17 cell-related cytokines in the pressure side of periodontal tissue in rats

目的探究不同正畸力下大鼠压力侧牙周组织中辅助性T细胞17(Th17)的特征性转录因子维甲酸相关孤儿受体γt(RORγt)和细胞因子白细胞介素-17(IL-17)表达的变化规律,及其对骨保护素(OPG)表达及破骨细胞(OC)数量的影响,初步探讨在不同力作用下Th17细胞对牙槽骨改建的影响。方法选取108只大鼠随机均分为3组,分别施加0、50、100 g力近中移动上颌第一磨牙,于0、1、3、5、7、14 d后处死。实时定量聚合酶链式反应法(Q-PCR)检测RORγt mRNA表达量;酶联免疫吸附法(ELISA)检测IL-17蛋白表达量;免疫组织化学染色法(IHC)检测RORγt、OPG蛋白表达量,并计数OC。结果50 g、100 g组的RORγt、IL-17和OC均呈先增高后降低趋势,峰值分别位于5、7 d,50 g组于14 d可基本恢复,而100 g组仍维持较高水平,其含量均为100 g组>50 g组>0 g组。OPG在50 g组呈降低-升高-降低趋势,14 d基本恢复,在100 g组呈先降低后升高趋势,50 g组在7 d、100 g组在14 d显著高于0 g组。结论不同正畸力下,RORγt、IL-17和OPG随时间呈规律性表达,说明Th17细胞通过分泌IL-17参与了压力侧牙周组织中的骨吸收过程。

Objective This study aimed to explore the changes in the expression of the characteristic transcription factor retinoid related orphan receptorγt(RORγt)and the cytokine interleukin-17(IL-17)of T helper cell 17(Th17)in the pressure side of the periodontal tissue of rats under different orthodontic forces.Their effects on the expression of osteoprotegerin(OPG)and the quantity of osteoclast(OC)were also explored.The role of Th17 cell in alveolar bone remodeling under different forces was preliminarily investigated.Methods A total of 108 rats were chosen and randomly divided into three groups.Mesial forces of 0,50,and 100 g were loaded on the maxillary first molar in the three groups.The rats were executed at 0,1,3,5,7,and 14 days.The expression of RORγt mRNA was quantified by real-time quantitative polymerase chain reaction.The expression of IL-17 protein was quantified by enzyme linked immunosorbent assay.The expression levels of RORγt and OPG proteins were quantified,and the quantity of OC was counted via immunohistochemistry.Results The expression levels of RORγt and IL-17 and the quantity of OC increased first and then decreased in the 50 and 100 g groups,and the peak values of the two groups were on days 5 and 7,respectively.The expression levels in the 50 g group basically recovered to normal level on day 14,while that in the 100 g group remained at a high level.The expression levels in the 50 g group were higher than those in the 0 g group and lower than those in the 100 g group.The expression of OPG in the 50 g group decreased first,then increased,and finally decreased.It basically recovered to normal level on day 14.The expression of OPG in the 100 g group decreased first and then increased.It remained at a high level on day 14.The expression in the 50 g group was significantly higher than that in the 0 g group on day 7,while the expression in the 100 g group was significantly higher than that in the 0 g group on day 14.Conclusion RORγt,IL-17,and OPG were expressed regularly over time under different orthodontic forces,indicating that Th17 participated in the process of bone resorption on the pressure side of periodontal tissue by secreting IL-17.