核因子κB受体活化因子配基在兔下颌骨牵引成骨过程中表达水平的变化

Expression of receptor activator for nuclear factor kappa B ligand in mandibular distraction osteogenesis in rabbit

目的：研究骨保护素配体即核因子xB受体活化因子配基（RANKL）在下颌骨牵引成骨过程中不同时期的表达水平变化，探讨其在成骨过程中的机制。方法：在成年大耳白兔的一侧下颌骨前部行骨切开术，用牵引器延长一侧下颌骨4mm，另一侧下颌骨行骨切开，作为对照组，分别于牵引完成后的第1、7、14、21、28天处死一组动物，取牵引区新生骨痂行RANKL免疫组织化学显色，通过细胞图像分析仪测量牵引区新骨中RANKL表达情况，利用SPSS软件采用方差分析进行统计分析。结果：下颌牵引延长后牵引间隙均有新骨形成，免疫组织化学显色显示RANKL主要定位于骨髓基质细胞的胞质中，其中以稳定期的第1、14天的表达最强。在稳定期第1、14天，实验组较对照组RANKL表达的阳性细胞率及阳性面积百分比差异有统计学意义，以后逐渐下降，第28天仅有微弱表达。结论：RANKL可能在牵引成骨过程中特别是调控组织细胞应力信号传递的早期发挥破骨作用。

Objective： To study the expression and function of receptor activator for nuclear factor kappa B ligand （RANKL） in the rabbit＇s mandibular distraction osteogenesis process. Methods： Unilateral mandibular osteotomy were performed in 30 mature rabbits. The mandibles of 30 rabbits were lengthened by 4 mm using a distractor, and the opposite side of the mature rabbit was cut in the mandible as a control group. At 1, 7, 14, 21, 28 days after the end of distraction, all animals were sacrificed and the distracted calluses were harvested and processed for irnmunohistochemistry study of RANKL. The expres- sion of RANKL in the distracted calluses was analyzed by cell digital imaging software. Finally the changes of RANKL were statis- tically analyzed by SPSS with the method of ANOVA. Results： The regenerated bone was found in the distraction gap after mandib- ular lengthening, and RANKL were co-localized in the bone marrow lining cells, osteoblasts and newly embedded osteocytes, the RANKL expression increased on 1 and 14 days. At the consolidation period of 1 and 14 days, there was a siganificant differ- ence between the experiment group and control group. There was significant difference between positive cells rate and posi- tive area percentage in distracted calluses. On the 28th day after the distraction, RANKL showed weak staining in the dis- tracted callus. Conclusion： RANKL may play important roles at the early stage of mandibular distraction.