Wang Dongmei, Wu Jiahong, Xu Zeyu, Jia Jinning, Lai Yimei, He Zhihua
Department of Physical Education, Anhui University of Technology, Maanshan, Anhui, China.
Department of Medicine, Sun Yat-Sen University, Shenzhen, Guangdong, China.
J Cell Mol Med. 2025 Feb;29(4):e70423. doi: 10.1111/jcmm.70423.
The global prevalence of skeletal muscle diseases has progressively escalated in recent years. This study aimed to explore the potential role of matrix stiffness in the repair mechanisms following skeletal muscle injury. We observed an increase in muscle stiffness, a significant rise in the number of type I muscle fibres and a notable elevation in mRNA expression levels of Myh7/2 alongside a decrease in Myh1/4 on day 3 post tibialis anterior muscle injury. To replicate these in vivo changes, C2C12 cells were cultured under high matrix stiffness conditions, and compared to those on low matrix stiffness, the C2C12 cells cultured on high matrix stiffness showed increased expression levels of Myh7/2 mRNA and production levels of MYH7/2, indicating differentiation into slow-twitch muscle fibre types. Furthermore, up-regulation of DRP1 phosphorylation along with elevated F-actin fluorescence intensity and RHOA and ROCK1 production indicates that high matrix stiffness induces cytoskeletal remodelling to regulate mitochondrial fission processes. Our data also revealed up-regulation in mRNA expression level for Actb, phosphorylation level for DRP1, mitochondrial quantity and MYH7/2 production level. Importantly, these effects were effectively reversed by the application of ROCK inhibitor Y-27632, highlighting that targeting cytoskeletal dynamics can modulate myogenic differentiation pathways within C2C12 cells. These findings provide valuable insights into how matrix stiffness influences fibre type transformation during skeletal muscle injury repair while suggesting potential therapeutic targets for intervention.
近年来，骨骼肌疾病的全球患病率呈逐步上升趋势。本研究旨在探讨基质硬度在骨骼肌损伤后修复机制中的潜在作用。我们观察到，在胫骨前肌损伤后第3天，肌肉硬度增加，I型肌纤维数量显著增加，Myh7/2的mRNA表达水平显著升高，同时Myh1/4降低。为了复制这些体内变化，将C2C12细胞在高基质硬度条件下培养，与低基质硬度条件下培养的细胞相比，在高基质硬度条件下培养的C2C12细胞显示出Myh7/2 mRNA表达水平和MYH7/2产生水平增加，表明分化为慢肌纤维类型。此外，DRP1磷酸化上调，同时F-肌动蛋白荧光强度、RHOA和ROCK1产生增加，表明高基质硬度诱导细胞骨架重塑以调节线粒体分裂过程。我们的数据还显示Actb的mRNA表达水平、DRP1的磷酸化水平、线粒体数量和MYH7/2产生水平上调。重要的是，应用ROCK抑制剂Y-27632可有效逆转这些效应，突出表明靶向细胞骨架动力学可调节C2C12细胞内的成肌分化途径。这些发现为基质硬度如何影响骨骼肌损伤修复过程中的纤维类型转变提供了有价值的见解，同时也提示了潜在的治疗干预靶点。
