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

摘要:

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）；③Western 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。

Abstract:

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 1st day after injury, and the tissues in the injury area of the two groups were taken for HE staining on the 1st d, 4th d, and 7th 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 (1st d: 0.158±0.015, t=3.229, P=0.032; 4th d: 0.203±0.004, t=6.069, P=0.004; 7th d: 0.149±0.009, t=2.821, P=0.048) expression was lower than that in the control group (1st d: 0.190±0.006; 4th d: 0.242±0.189; 7th 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 mJ/mm², expressions in the treatment group (1st d: 0.998±0.163; 4th d: 1.155±0.059; 7th d: 0.733±0.077) were higher than those in the control group (1st d: 0.410±0.115; 4th d: 0.560±0.194; 7th 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 mJ/mm², expressions in the ESW group (1st d: 0.131±0.044; 4th d: 0.383±0.022; 7th d: 0.162±0.027) were lower than those in the control group (1st d: 0.388±0.060; 4th d: 0.829±0.192; 7th d: 0.508±0.112). Conclusion: This experiment confirms that ESW can promote the repair of skeletal muscle injury in rats.