渐进性咬合紊乱大鼠的髁突软骨中Ihh、Smo及Ptch1表达变化

The expression changes of Ihh, Smo and Ptch1 on rat condylar cartilage in the experimentally created disordered occlusion

目的探讨Indian Hedgehog(Ihh)及其受体Smoothened(Smo)和Patched1(Ptch1)在渐进性咬合紊乱的大鼠髁突软骨-骨改建中的表达变化情况。方法选用24只8周龄雌性SD大鼠,实验组施以渐进性咬合紊乱,分别于20和24周后取材,苏木精-伊红染色观察组织形态变化,免疫组化及实时定量PCR方法检测Ihh、Smo和Ptch1的表达情况。结果髁突软骨后部20周实验组明显增厚(F=4.39,P=0.003),但24周组有所缓解。免疫组化检测24周实验组Ihh的表达水平高于对照组(F=3.78,P=0.02),而20周实验组Smo的表达水平高于对照组(F=5.16,P=0.04)。实时定量PCR结果显示,20周实验组Ihh(F=7.80,P=0.012)和Smo(F=15.67,P=0.003)的mRNA水平均高于对照组;24周实验组Ihh的mRNA水平表达水平显著高于对照组(F=13.34,P=0.013),Ptch1的表达差异无统计学意义(F=1.34,P=2.13)。结论渐进性咬合紊乱促进了大鼠髁突软骨中Ihh及其受体Smo的高表达。

Objective To explore the effects of experimentally created disordered occlusion （ECDO） on the expression of Indian Hedgehog （Ihh） and its receptors Patched1 （Ptch1） and Smoothened （Smo） in the mandibular condyle of SD rats.Methods Twenty four female SD rats （8-week old） were randomly divided into the experimental and the control groups.In experimental group,the progressive disordered occlusion was created by using orthodontic techniques.The rats were sacrificed on 20 weeks or on 24 weeks,respectively.HE staining was performed to detect the histological changes,and immunohistochemical analysis and real time-polymerase chain reaction were applied to evaluate the expression of Ihh,Ptch1 and Smo.Results On 20 weeks,the thickness of condylar cartilage in experimental group significantly increased （F=4.39,P=0.003） and eased down on 24 weeks.The immunohistochemical expression level of Ihh on 24 weeks was higher than that of the control group （F=3.78,P=0.02）,and the Smo expression on 20 weeks of the experimental group was higher than that of the control group （F=5.16,P=0.04）.Real time-PCR results showed that Ihh （F=7.80,P=0.012） and Smo （F=15.67,P=0.003） levels of mRNA in 20-week experimental group were higher than those of the control group; and also on 24 weeks the mRNA level of Ihh was significantly higher than that of the control group （F=13.34,P=0.013）.The expression of Pth1 showed no statistically significant difference between the experimental and the control group.Conclusion ECDO promoted higher expression of Ihh and its receptor Smo in mandibular condylar cartilage of rats.