BMP/Smads信号传导通路在兔下颌持续前导后髁突的表达

Expression of BMP/Smads in rabbit condylar cartilage during mandibular forward positioning

目的:探讨兔下颌持续功能前导后髁突软骨中BM P/Sm ads信号传导通路表达与髁突改建的关系。方法:60只8周龄的日本大耳白兔,随机分成实验组(n=36)和对照组(n=24),实验组动物每日24 h戴用咬合前导矫正器。实验动物分别在第3天、1周、2周、4周、8周及12周时处死并取材,用免疫组化方法观测髁突组织内BM P-2和Sm ad1/5、4、6的分布和表达,并对其表达进行灰度测定。结果:BM P-2和Sm ad1/5、4、6主要在髁突软骨过渡层和肥大层软骨细胞中表达,钙化层的软骨细胞和成骨细胞中也可见BM P-2和Sm ad1/5、4、6的表达。实验组兔髁突软骨BM P-2和Sm ad1/5、4、6的表达强度在早期高于同期对照组(P<0.05),与髁突骨组织改建的活跃程度同步。结论:下颌持续前导后,Sm ad1/5、4、6作为BM P-2的细胞内信号传导分子,与下颌髁突适应性生长改建关系密切。

Objective： To identify the relationship between the expression of BMP/Smads in condylar cartilage and condylar grovth modifications in rabbits during mandibular forward positioning. Methods： Sixty male rabbits with 8 weeks of age were randomly divided into the experimental group （n = 36） and control group （n = 24）. The mandibles of rabbits in the experimental groups were induced to forward position by a functional appliance. The rabbits in the experimental group and control group were sacrificed after 3 days and 1,2,4,8, 12 weeks, respectively. The expression of BMP-2,Smad1/5,4 and 6 in condylar cartilage was examined by immunohistochemical staining. Results： The expression of BMP-2,Smad1/5, 4 and 6 was mainly found in the chondrocytes from the transitional zone and hypertrophic zone,and was also found in the chondrocytes and osteoblasts of the mineralized zone. Compared with those of the agematched controls,the positive signals for BMP-2,Smad1/5,4 and 6 in the experimental animals were stronger at early stage（P〈0.05） ,coinciding with the remodeling in condylar cartilage after functional appliance. Conclusion： The expression of BMP-2,Smad1/5,4 and 6 is associated with the adaptive remodeling of the condylar cartilage after functional appliance.