Radial Extracorporeal Shock Wave Reduce Myogenic Contracture and Muscle Atrophy via inhibiting NF-κB/HIF-1α Signaling Pathway in Rabbit
BackgroundRecent studies have shown that radial extracorporeal shock wave therapy (rESWT) modulates viability and gene expression of human skeletal muscle cells in vitro. However, the underlying biological effects and mechanisms of rESWT on muscle atrophy and myogenic contracture in animal mode have not yet been investigated.ObjectiveTo investigate the underlying biological effects and mechanisms of rESWT on myogenic contracture and muscle atrophy in a rabbit model of extending knee joint
... ng knee joint contracture.MethodsForty rabbits were randomly divided into eight groups. In group Control, the left knee joint was not fixed. In group I-4w, the left knee joint was only fixed for four weeks. In groups SR-1w, SR-2w, and SR-4w, the left knee joint was fixed for four weeks before the rabbits underwent one, two, and four weeks of self-recovery, respectively. In groups rESWT-1w, rESWT-2w, and rESWT-4w, the left knee joint was fixed for four weeks before the rabbits underwent one, two, and four weeks of rESWT, respectively. The degree of myogenic contracture was measured, the cross-sectional area and key protein levels for NF-κB/HIF-1α signaling pathway and myogenic regulatory factors of the rectus femoris were evaluated.ResultsDuring the recovery period, biological findings in this study showed that the levels of myogenic contracture and muscle atrophy were milder in group rESWT by compared with group SR at the same time point. Molecular biological analysis in the present study showed that MyoD protein levels in the group rESWT was significantly higher than those in the group SR, and importantly, phospho-NF-κB p65 and HIF-1α protein levels in the group rESWT were significantly lower than those in the group SR at the same time point.ConclusionsOur study demonstrates that rESWT has the potential to reduce myogenic contracture and muscle atrophy after long-term immobilization in animal model. It is a possible mechanism that changing the low oxygen environment in skeletal muscle through rESWT may inhibit activation of NF-κB/HIF-1α signaling pathway, thereby enhancing the expression of myogenic regulatory factors.