Abstract
Chinese Tumor necrosis factor α (TNFα) exhibits diverse biological functions; however, its regulatory roles in myogenesis are not fully understood. In the present study, we explored the function of TNFα in myoblast proliferation, differentiation, migration, and myotube fusion in primary myoblasts and C2C12 cells. To this end, we constructed TNFα muscle-conditional knockout ( TNFα-CKO) mice and compared them with flox mice to assess the effects of TNFα knockout on skeletal muscles. Results indicated that TNFα-CKO mice displayed phenotypes such as accelerated muscle development, enhanced regenerative capacity, and improved exercise endurance compared to flox mice, with no significant differences observed in major visceral organs or skeletal structure. Using label-free proteomic analysis, we found that TNFα-CKO altered the distribution of several muscle development-related proteins, such as Hira, Casz1, Casp7, Arhgap10, Gas1, Diaph1, Map3k20, Cfl2, and Igf2, in the nucleus and cytoplasm. Gene set enrichment analysis (GSEA) further revealed that TNFα deficiency resulted in positive enrichment in oxidative phosphorylation and MyoD targets and negative enrichment in JAK-STAT signaling. These findings suggest that TNFα-CKO positively regulates muscle growth and development, possibly via these newly identified targets and pathways. 肿瘤坏死因子α（TNFα）具有多种生物学功能，然而它在肌生成中的作用尚不清晰。该研究旨在阐明 TNFα对原代成肌细胞和C2C12肌细胞增殖、迁移、分化和肌管融合的作用，通过构建骨骼肌条件性敲除小鼠，探究 TNFα缺乏对肌肉发育和再生的影响。结果显示， TNFα-CKO小鼠表现出更快的肌肉发育速度、更强的运动耐力和肌肉再生能力，同时内脏和骨骼并未见差异。此外， TNFα缺失导致一些肌肉发育相关蛋白在细胞质和细胞核中的分布发生改变，包括Hira、Casz1、Casp7、Arhgap10、Gas1、Diaph1、Map3k20、Cfl2和Igf2等。GSEA分析显示 TNFα缺失导致基因集正向富集在氧化磷酸化和MyoD靶点上，负向富集在JAK-STAT信号通路中。这些结果说明 TNFα-CKO通过调节上述蛋白和信号通路促进肌肉生长发育。.