体外冲击波对大鼠骨骼肌损伤修复研究

Study on repair of skeletal muscle injury by extracorporeal shock wave in rats

目的:探讨体外冲击波(extracorporeal shock wave,ESW)对骨骼肌损伤修复的影响,为临床应用ESW治疗骨肌疾病提供理论依据。方法:建立骨骼肌钝挫伤模型,将实验分为治疗组、对照组。治疗组在损伤后第2天进行ESW治疗,治疗组和对照组于治疗第1、4、7天取损伤区域组织进行HE染色观察组织形态;免疫组化检测肌肉生长抑制素(myostatin,Mstn)的表达,并利用图像分析软件进行平均光密度(average optical density,AOD)分析;Western blot检测生肌决定因子(Myod)、Mstn蛋白的表达水平。结果:(1)治疗组肌纤维萎缩逐渐减轻,炎症细胞浸润减少,期间可见大量新生肌细胞,治疗后肌纤维排列整齐。(2)免疫组化结果显示,治疗组Mstn(第1天:0.158±0.015,t=3.229,P=0.032;第4天:0.203±0.004,t=6.069,P=0.004;第7天:0.149±0.009,t=2.821,P=0.048)表达低于对照组(第1天:0.190±0.006;第4天:0.242±0.189;第7天:0.171±0.011);(3)Western blot结果显示,Myod蛋白治疗组的表达量随着强度的增加呈上升后下降的趋势(F=50.074;P=0.000),且随着时间的变化表达量也呈先上升后下降的趋势(F=46.217;P=0.000);在0.14 mJ/mm2下,治疗组(第1天:0.998±0.163;第4天:1.155±0.059;第7天:0.733±0.077)表达均高于对照组(第1天:0.410±0.115;第4天:0.560±0.194;第7天:0.250±0.103)。Mstn蛋白随着冲击强度的增加,表达量呈逐渐减少的趋势(F=86.103;P=0.000),不同时间的表达量先上升后下降(F=32.380;P=0.000);0.14 mJ/mm2强度下,治疗组(第1天:0.131±0.044;第4天:0.383±0.022;第7天:0.162±0.027)表达均低于对照组(第1天:0.388±0.060;第4天:0.829±0.192;第7天:0.508±0.112)。结论:本实验证实ESW能够促进大鼠骨骼肌损伤的修复。

Objective:To investigate the effect of extracorporeal shock wave(ESW)on repair of skeletal muscle injury,so as to provide theoretical basis for clinical application of ESW in the treatment of skeletal muscle disease. Methods:A model of skeletal muscle blunt contusion was established,and the experiment was divided into the ESW group and the injury group. The ESW group were treated with ESW on the 1 st day after injury,and the tissues in the injury area of the two groups were taken for HE staining on the 1 st d,4 th d,and 7 th d after treatment to observe the tissue morphology;immunohistochemistry was used to detect the expression of myostatin(Mstn),and the images analysis software was used to perform average optical density(AOD)analysis;Western blot was used to detect expression levels of Myod and Mstn protein. Results:In the ESW group,the muscle fiber atrophy was gradually alleviated and the inflammatory cell infiltration was decreased. During this period,a large number of new muscle cells were seen and post-treatment muscle fiber was lined up in order. Results of immunohistochemistry showed that Mstn(1 st d:0.158±0.015,t=3.229,P=0.032;4 th d:0.203±0.004,t=6.069,P=0.004;7 th d:0.149±0.009,t=2.821,P=0.048)expression was lower than that in the control group(1 st d:0.190±0.006;4 th d:0.242±0.189;7 th d:0.171±0.011). Western blot results showed that the expression of Myod protein in the ESW group was firstly increased with increasing intensity and then decreased(F=50.074,P=0.000). And over time,the amount of expression also showed a trend of rising at first and then falling(F=46.217,P=0.000). With the concentration of 0.14 m J/mm2,expressions in the treatment group(1 st d:0.998±0.163;4 th d:1.155±0.059;7 th d:0.733±0.077)were higher than those in the control group(1 st d:0.410±0.115;4 th d:0.560±0.194;7 th d:0.250±0.103).With the increase of the impact strength,the expression of Mstn protein was gradually decreased(F=86.103,P=0.000). Expression at different time was risen at first and then decreased(F=32.380,P=0.000). With the concentration of 0.14 m J/mm2,expressions in the ESW group(1 st d:0.131±0.044;4 th d:0.383±0.022;7 th d:0.162±0.027)were lower than those in the control group(1 st d:0.388±0.060;4 th d:0.829±0.192;7 th d:0.508±0.112). Conclusion:This experiment confirms that ESW can promote the repair of skeletal muscle injury in rats.