颌间Ⅲ类矫形力作用下转化生长因子β1在髁突软骨中的基因表达

The Expression of TGF-β1 mRNA in Pubescent Rhesus Monkeys′ Condyle under Class Ⅲ Intermaxillary Functional Orthopedic Force

目的 观察颌间Ⅲ类矫形力不同作用时间下转化生长因子 β1(TGF_β1)在髁突软骨中的基因表达。 方法 选用青春生长发育期雌性恒河猴 6只 ,随机分为 3、6月实验组和对照组 ,实验组戴用颌间Ⅲ类双阻板磁力矫治器 ,对照组不戴。苏木精—伊红染色观察髁突软骨组织形态 ,原位杂交方法检测髁突软骨TGF_β1mRNA的表达 ,并进行统计学处理。结果 ①组织学观察表明 :与对照组相比 3月组髁突软骨前份有一定程度增厚 ,中、后份变薄 ;6月组髁突软骨厚度变化与 3月组相似。②原位杂交结果表明 :对照组TGF_β1mRNA前份表达较弱 ,中、后份表达较强 ;3月组髁突软骨前中后份TGF_β1mRNA表达均增强 ,以前份最强 ;6月组髁突软骨TGF_β1mRNA表达比 3月组明显减少 ,但前份仍强于中后份。实验组之间以及实验组与对照组之间的差异均有统计学意义 (P <0 0 1)。结论 髁突软骨TGF_β1mRNA的表达强弱与颌间Ⅲ类矫形力不同的作用时间有关。 3月组TGF_β1mRNA表达较 6月组明显 ,提示

Objective To investigate the expression of TGF-β1mRNA in pubescent Rhesus monkeys′ condylar under Class Ⅲ intermaxillary functional orthopedic force for different lengths of time. Methods Six pubescent Rhesus monkey were divided into two test groups and a control group. Monkeys in the test groups wore TMAⅢ while the control groups did not. Histological method (HE staining) and in situ hybridization were employed in this study. Results ①The histological results showed that, compared with the control group, the anterior part of the condyle became thicker while the median part and the posterior part became thinner in 3 months group. However, in 6 months group,the change was similar to 3 months group. ②The results of in situ hybridization showed that, in control group, TGF-β1 mRNA mildly expressed in the anterior part of the condyle while extensively in the median and posterior parts. In 3 months group, TGF-β1 mRNA expressed in all parts of condyle; the most intensive expression was in the anterior part. Compared with 3 months group, the expression of TGF-β1 mRNA decreased in 6 months group, but the expression in anterior part was stronger than in median and posterior parts. Conclusion Under Class Ⅲ Orthopedic therapy, TGF-β1 mRNA probably participated in the endochrondral bone remodeling in the condyle, and the expression was closely related to loading time. In 3 months group, the expression of TGF-β1 mRNA was stronger than that in 6 months group. It was inferred that the remodeling of endochrondral bone was more active in 3 months group.