miR-222在大鼠骨骼肌损伤再修复中的表达

The Expression of miR-222 in Repair of Skeletal Muscle Injury in Rats

为分析miR-222在骨骼肌损伤修复中的表达水平,本研究选取跑台诱导骨骼肌损伤模型,参照Armstrong的实验动物模型,选取2月龄健康雄性SD大鼠,建立股直肌损伤模型,在下坡跑运动结束后的不同时刻取材,对血清CK水平进行检测,对股直肌冰冻切片(HE染色;横切)进行组织形态学分析,采用RT-PCR试验对miR-222水平进行检测。血清CK在股直肌运动后损伤过程中的表达水平持续增高;HE染色发现:安静对照组显示肌纤维排列紧密规律,大小均匀,呈多边形;与对照组相比,运动后不同时刻取材的组织切片染色显示肌纤维之间间隙变大,形状不规律,呈肿胀状态;miR-222在运动后表达较对照组整体上调。一次性长时间下坡跑运动可导致大鼠股直肌损伤,损伤后2周肌纤维细胞结构基本恢复正常,通过血清CK的变化特点,血清CK可作为运动性骨骼肌损伤评价的敏感指标之一。一次性下坡跑诱导的运动性骨骼肌损伤中miR-222表达上调,促进了骨骼肌损伤的修复。

This study explored the expression of miR-222 in the repair of skeletal muscle injury. Model of skeletal muscle injury induced by treadmill was selected in this research, and the rectus femoris injury model was constructed based on two months old SD rats according to the animal model of Armstrong＇s experiment. After the downhill movement, the level of serum CK was detected, histological analysis of frozen sections of femoral rectus （HE staining; crosscutting） was performed, and the expression of miR-222 was detected by RT-PCR at different time points. The results showed that the expression level of serum CK in the process of rectus muscle injury continued to increase. The result of HE staining demonstrated that muscle fibers arranged in close laws and uniform size and they were polygonal in the quiet control group. Compared with control group, the staining result of tissue section at different time points after movement showed that the gap between muscle fibers became larger, the shape was irregular, and they were in swelling state. In addition, the expression of miR-222 after movement was increased compared with the control group. Serum CK could be used as a sensitive index for the evaluation of exercise-induced skeletal muscle injury with its change characters. The expression of miR-222 was up-regulated in the exercise-induced skeletal muscle injury induced by the one-time downhill running, which promoted the repair of skeletal muscle injury.