Temporal Dynamics of Gene and Protein Expression Follow Volumetric Muscle Loss

Here, we performed time-series analysis of transcriptomic and proteomic changes associated with VML in a mouse model, focusing on the dynamics of gene and protein expression patterns at up to three weeks after muscle injury. We identified signaling pathways associated with temporal expression patterns that fail to restore within 3 weeks after VML, including those with sustained upregulation or downregulation. Using temporal expression analysis, we identified Sp1 as a novel molecular mediator of dysregulated muscle recovery after VML as well as elucidated pro-inflammatory and extracellular matrix (ECM) remodeling pathways mediating the remodeling process. These insights pave the way for the development of new targets that promote muscle regeneration and functional recovery of traumatically injured muscle. Overall design: We utilized a well-established mouse partial-thickness VML model, in which 40% of the tibialis anterior muscle in C57BL/6 (8-week-old male) mice was unilaterally excised, based on our previous work . At time points of 3, 7, 14, and 21 days after the induction of VML, the tibialis anterior muscles were explanted for RNA extraction (n=5-6 samples per time point).

本研究针对小鼠模型中与容积性肌肉丢失（Volumetric Muscle Loss，VML）相关的转录组与蛋白质组变化开展时间序列分析，重点聚焦肌肉损伤后至多三周内的基因与蛋白质表达谱动态特征。我们鉴定出与VML后三周内未能恢复的时序表达模式相关的信号通路，包括持续上调或持续下调的通路。通过时序表达分析，我们鉴定出Sp1作为VML后肌肉修复失调的新型分子介导因子，并阐明了调控该重塑过程的促炎通路与细胞外基质（extracellular matrix，ECM）重塑通路。这些研究发现为开发促进创伤性损伤肌肉的肌再生与功能恢复的新型靶点奠定了基础。
实验整体设计：基于本团队前期研究工作，我们采用已成熟建立的小鼠部分厚度VML模型，对C57BL/6品系（8周龄雄性）小鼠的单侧胫骨前肌实施40%体积切除操作。在VML造模后的第3、7、14及21天，采集胫骨前肌组织用于RNA提取，每个时间点设置5-6个生物学重复样本。