| ObjectiveTo observe the effect of radial extracorporeal shock wave therapy on myogenic indicators during the repair of skeletal muscle blunt contusion and IGF-1/PI3K/AKT signaling pathway expression in rats,in order to preliminarily explore the possible biological mechanism of shock wave therapy on the repair of skeletal muscle injury.MethodsTo get 66 male adult SD rats from SPF laboratory animal center of Jinzhou Medical University,they were divided into normal group(n=12)、model group and treatment group(two groups n=54)by random number table method,and the gastrocnemius injury model of the model group and treatment group was established by the self-made heavy striking device.After hit 12h randomly selected 6 rats to check whether the muscles were demaged successfully.Then the rats were randomly divided into model group(n=24)and treatment group(n=24),and the normal group was fed normally and without any treatment;The moment of building the animal model can set it as 0 point,next 24h as 1d,and so on.The rats in the treatment group were treated 24h after modeling with shock wave of 0.14 mJ/mm2,10 Hz,each shocked 500 times and interval of 4 days for the second treatment.Gastrocnemius of each group were collected immediately at 1d、3d、5d、7d(among them,1d and 5d immediately removed muscles after shock wave therapy).Observed the muscle fiber arrangement using the HE staining,and the expression of Myostatin,Myod1,IGF-1,PI3K,AKT and p-AKTs473 were detected using the immunohistochemistry and western blot.Results1.HE staining results:In the normal group,muscle satellite cells arranged in a neat and compact arrangement.The size of muscle fiber space was the same,and the cell nucleus were evenly distributed at the edge of muscle cells.Compared with the normal group,the arrangement gap of the muscle cells was increased in the model group,and the muscle satellite cells migrated to the damaged area,a few mononuclear or polynuclear muscle tubes appeared.The regeneration and repair effect of the treatment group at the same time points was better than that in the model group.2.Different protein expression results:(1)Expression of myoblast regulators:Compared with the normal group,expression of Myod1 was significantly increased at 1d and 3d in the model group(P<0.01),but there was no statistical difference at 5d and 7d in the model group(P>0.05).At the same time,the expression of Myod1 in the treatment group was higher than that in the normal group and model group(all P<0.01).Immunohistochemistry and western blot results showed that the expression of Myostatin in the model group was higher than that in the normal group at the same time points(P<0.01),and the expression in the treatment group was significantly lower than that in the model group(P<0.05),and there was no statistical difference between the 7d treatment group and the normal group(P>0.05).(2)Expression of signaling pathway proteins:At the same time point,the expression levels of IGF-1 and p-AKTs473 in the model group and treatment group were both higher than those in the normal group(P<0.05),and the expression levels in the treatment group were significantly higher than those in the model group(P<0.01).The expression of PI3K in the model group and treatment group was higher than that in the normal group(P<0.05 in the 1d and 7d model group,P<0.01 in the rest).Compared with the model group,the expression of PI3K in the treatment group was significantly increased at 1d and 3d(P<0.01),but there was no statistical difference at 5d and 7d(P>0.05).At the same time,the expression of AKT in the model group and treatment group was significantly higher than the normal group(all P<0.01),but there was no statistical difference between the treatment group and the model group(P>0.05).Conclusions1.Radial extracorporeal shock wave therapy can positively regulate the repair process of skeletal muscle blunt contusion,which has an impact on the expression of Myod1 and Myostatin.2.The positive regulation effect of radial extracorporeal shock wave on skeletal muscle blunt contusion in rats is related to the IGF-1/PI3K/AKT signaling pathway to some extent,which provides a theoretical basis for the application of shock wave in the treatment of skeletal muscle blunt contusion in clinical and sports injuries. |
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