大鼠骨骼肌挫伤修复过程中p38MAPK通路、炎症反应的作用

Analysis of the role of p38MAPK pathway and inflammatory response in the repair of skeletal muscle contusion in rats

目的研究冲击波对大鼠骨骼肌钝挫伤修复过程中p38丝裂原活化蛋白激酶(MAPK)信号通路的影响,观察冲击波对骨骼肌钝挫伤治疗效果及调控机制。方法将雄性SD大鼠60只,随机分为正常组(n=12)、损伤组(n=24)和治疗组(n=24),后两组采用重物装置砸击腓肠肌造成急性钝挫伤。治疗组大鼠于损伤24 h后给予冲击波,每间隔4 d进行1次治疗,于1 d、3 d、7 d、14 d时取大鼠腓肠肌中段肌腹进行检测。采用苏木素-伊红(HE)染色观察肌纤维变化,Western印迹检测p38丝裂原活化蛋白激酶(p38MAPK)、磷酸化p38MAPK(p-p38MAPK)、肌细胞生成素(Myogenin)的蛋白水平,酶联免疫吸附试验(ELISA)检测组织肿瘤坏死因子(TNF)-α、白细胞介素(IL)-1β炎症因子含量。结果与正常组相比,损伤组肌纤维排列紊乱,炎症细胞大面积浸润;治疗组肌纤维逐渐排列较规则,炎症细胞减少。各个时间点,损伤组较正常组p38MAPK、p-p38MAPK、Myogenin表达量增加(P<0.01),同一时间点下,治疗组较损伤组p38MAPK、p-p38MAPK、Myogenin表达量升高(P<0.05)。损伤组各个时间点较正常组TNF-α、IL-1β明显升高(P<0.01),但治疗组除了1 d高于损伤组,3 d、7 d、14 d均低于损伤组(P<0.05),差异具有统计学意义。结论冲击波通过p38MAPK信号通路促进肌卫星细胞增殖,同时减少炎症反应,从而治疗骨骼肌钝挫伤修复。

Objective To study the effect of extracorporeal shock wave on p38MAPK pathway during the repair of acute injury in rats with skeletal muscle contusion,to observe the therapeutic effect and modulation mechanism of shock wave on skeletal muscle blunt injury.Methods 60 male SD rats were randomly divided into normal group(n=12),injury group(n=24)and treatment group(n=24)and the latter two groups used heavy equipment to strike gastrocnemius muscle to cause acute bluntness.Shock wave therapy was performed every 4 days after 24 hours of injury in the treatment group,and the middle segment of the rat gastrocnemius muscle was examined on the 1st,3rd,7th and 14th day.The morphological changes of muscle tissue were observed by using HE staining.Western blot was used to detect the protein levels of p38 mitogen-activated protein kinase(p38MAPK),phosphorylated p38MAPK(p-p38MAPK)and Myogenin(Myog).ELISA was used to detect tumor necrosis factor(TNF)-α,interleukin(IL)-1βcontent.Results HE staining showed that compared with the normal group,the muscle fibers of the injury group were arranged disorderly,and inflammatory cells invaded a large area;the muscle fibers of the treatment group were gradually arranged more regularly,and the inflammatory cells were reduced.Western blot results:at each time point,the expression of p38MAPK,p-p38MAPK,and Myog increased in the injury group compared with the normal group.At the same time point,the expression of p38MAPK,p-p38MAPK,and Myog in the treatment group increased compared with the injury group(P<0.05).The results of ELISA showed that TNF-αand IL-1βin the injury group were significantly higher than those in the normal group at various time points(P<0.01).But at the same time point,TNF-αand IL-1βin the treatment group were higher than those of the injury group on the first day,and lower that those of the injury group at 3,7 and 14 day(P<0.05).The differences were all statistically significant.Conclusions The shock wave could promote the proliferation of muscle satellite cells by the p38MAPK signaling pathway and reduce inflammatory response to treat skeletal muscle injury.