跑台运动对去卵巢大鼠骨组织中OPG、RANKL和RUNX2 mRNA表达的影响

Effects of treadmill exercise on mRNA expression levels of osteoprotegerin,RANKL and RUNX2 in bone tissues of ovariectomized rats

目的:观察去卵巢大鼠经跑台运动后其骨组织中OPG、RANKL和RUNX2 mRNA表达变化,探讨力学刺激防治绝经后骨质疏松的作用机制。方法:健康3月龄雌性SD大鼠30只,体重(270±10)g,按随机方法平均分为假手术组、去卵巢组和跑台运动组,每组10只。假手术组仅在术中牵动卵巢并不行卵巢切除,其余两组均行卵巢切除术。假手术组和去卵巢组大鼠正常饲养;跑台运动组大鼠在术后1周开始在动物跑台上运动,跑速为18 m/min,每次45 min,1次/d,6 d/周,共训练11周。12周后处死所有动物,取左侧股骨头,脱钙后石腊切片,用倒置相差显微镜观察其组织学变化;取右股骨头提总RNA,实时PCR法检测OPG、RANKL和RUNX2的mRNA表达情况。结果:去卵巢组骨小梁稀疏,骨细胞少,跑台运动组骨小梁粗壮增厚。去卵巢组骨组织中OPG的mRNA表达为(0.131±0.080),RNAKL的mRNA表达为(8.013±3.550),RUNX2的mRNA表达为(3.245±5.090)。跑台运动组其骨组织中OPG的mRNA表达为(0.566±0.260),RANKL的mRNA表达为(5.232±3.670),RUNX2的mRNA表达为(2.753±3.680)。和去卵巢组比较,跑台运动组的OPG的mRNA表达升高,差异有统计学意义;而RANKL和RUNX2的表达下降,差异无统计学意义。结论:力学刺激能通过促进去卵巢大鼠骨组织中OPG的表达而发挥其抗绝经后骨质疏松的效果,这对今后研究绝经后骨质疏松症的治疗提供了新的思路。

Objective ：To observe the effect of treadmill exercise on the mRNA expression of osteoprotegerin, RANKL and RUNX2 in bone tissue of ovariectomized rat,and to investigate the mechanism of treadmill exercise for the preventing and treating postmenopausal osteoporosis. Methods ：Thirty healthy adult SD rats which average weight was （270±10） g were randomly divided into 3 groups：sham-operation group, ovariectomized group and treadmill exercise group. Each group had 10 rats. After anesthesia, ovariectomized group and treadmill exercise treated group were operated by bilateral ovarian resection, sham group by sham operation. Shamoperation group and ovarian rats were normal breed. Rats in the exercise group were treated by running on treadmill for animal at 1 week after the operation. Running speed was 18 meters per minutes lasting 45 minutes in one day, and worked six days per week for 11 weeks. All rats were killed after 12 weeks. After decalcification,left femur head was made to paraffin slice and observed by inverted phase contrast microscope for histological examination. Total RNA were extracted from the right femur heads and the mRNA expression of OPG, RANKL and RUNX2 were examined by real time PCR. Results：The femur heads of ovariectomized group showed thin trabecular bone and less bone cells, meanwhile trabecular bone of exercise group looked thicker in histological examination. The mRNA expression of OPG （0.151±0.080）, RANKL （8.013± 3.550） and RUNX2 （3.245±5.090） was seen in the ovariectomized group. Meanwhile different results were found as the mRNA expression of OPG （0.566±0.260）, RANKL （5.232±3.670） and RUNX2 （2.753±3.680） in the group of treadmill exercise. In compared with ovariectomized group, the mRNA expression of OPG in treadmill exercise increased and the result had statistical significance,whereas mRNA expression of RNAKL and RUNX2 decreased but the results had no statistical significance. Conclusion ：The effect of exercise treating postmenopausal osteoporosis is tightly correlated with the up-regulation of expression of OPG. This provides a new train of thought of postmenopausal osteoporosis treatment for the future study.