被动牵张运动通过调控AMPK/PGC-1α/FOXO3信号通路对衰老骨骼肌细胞的影响

关键词：牵张运动  骨骼肌减少症  线粒体自噬  线粒体功能  腺苷酸活化蛋白激酶

Keywords:passive stretching  sarcopenia  mitophagy  mitochondrial function  adenylate-activated protein kinase

摘要：

      摘要 目的：探索被动牵张运动对衰老骨骼肌细胞影响及其作用机制，为运动能力严重丧失重度骨骼肌减少症患者提供有效的干预实验数据。 方法：将C2C12（小鼠成肌细胞）培养分化为骨骼肌细胞并利用Ｄ-gal药物诱导其衰老，以此建立体外衰老骨骼肌细胞模型。采用Flex Cell力学系统对衰老骨骼肌细胞进行循环牵张刺激（0.5Hz，24h）。通过线粒体膜电位、抗氧化剂含量、细胞增殖能力（EdU）和β-半乳糖苷酶染色等检测分析骨骼肌细胞衰老状态。通过蛋白印迹分析AMPK/PGC-α/FOXO3蛋白表达变化。 结果：被动牵张运动降低了衰老骨骼肌细胞的衰老阳性率（18.03%±6.82%），与衰老组（42.86%±10.54%）相比差异显著（P<0.05）。被动牵张后，细胞内AMPK和PGC-1α的表达水平升高，而FOXO3的表达水平降低，与衰老组相比差异显著（P<0.05）。此外，虽然被动牵张提高了线粒体膜电位，但可能降低了衰老骨骼肌细胞的抗氧化剂含量，这可能与PGC-1α的表达水平有关。 结论：被动牵张运动可能是通过调节衰老骨骼肌细胞中AMPK/PGC-1α/FOXO3信号传导轴以及氧化应激水平来改善骨骼肌细胞的衰老状态。

Abstract:

      Abstract Objective： To explore the effects of passive distraction training modalities on aging skeletal muscle cells and its underlying mechanisms， and to provide experimental data on effective interventions for patients with severe loss of locomotor capacity in severe skeletal sarcopenia. Method： An in vitro skeletal muscle cell aging model by C2C12 differentiated skeletal muscle cells with D-galactose stimulation were established. Aging skeletal muscle cells were subjected to cyclic stretch （0.5Hz， 24h） using an FX-5000 Flex Cell Tension system. Senescence and oxidative stress levels were assessed through mitochondrial membrane potential, antioxidant content, EdU assay, and β-galactosidase staining. The expression of AMPK/PGC-α/FOXO3 signaling molecules related to muscle cell protein synthesis and decomposition in the cells was analyzed by Western Blot. Result： Passive stretching significantly reduced the positive rate of aging in senescent skeletal muscle cells （18.03%±6.82%) compared with the aging group （42.86%±10.54%, P<0.05）. The expression levels of intracellular AMPK and PGC-1α significantly increased after passive stretching， while the expression of FOXO3 decreased significantly compared to the aging group（P<0.05）. In addition， passive stretching increased the mitochondrial membrane potential but appeared to reduce the antioxidant content in aging skeletal muscle cells， potentially related to changes in PGC-1α expression levels. Conclusion： Passive stretching improved the aging state of skeletal muscle cells by modulating the AMPK/PGC-1α/FOXO3 signaling pathway and oxidative stress levels， revealing the great potential of passive stretching as the treatment for severe sarcopenia.