Muscle trauma frequently occurs in daily life. However, the molecular mechanisms of muscle healing, which partly depend on the extent of the damage, are not well understood. This study aimed to investigate gene expression profiles following mild and severe muscle contusion, and to provide more information about the molecular mechanisms underlying the repair process. A total of 33 rats were divided randomly into control (n = 3), mild contusion (n = 15), and severe contusion (n = 15) groups; the contusion groups were further divided into five subgroups (1, 3, 24, 48, and 168 h post-injury; n = 3 per subgroup). A total of 2,844 and 2,298 differentially expressed genes were identified using microarray analyses in the mild and severe contusions, respectively. From the analysis of the 1,620 coexpressed genes in mildly and severely contused muscle, we discovered that the gene profiles in functional modules and temporal clusters were similar between the mild and severe contusion groups; moreover, the genes showed time-dependent patterns of expression, which allowed us to identify useful markers of wound age. The function analyzes of genes in the functional modules and temporal clusters were performed, and the hub genes in each module-cluster pair were identified. Interestingly, we found that genes downregulated at 24-48 h were largely associated with metabolic processes, especially of the oxidative phosphorylation, which has been rarely reported. These results improve our understanding of the molecular mechanisms underlying muscle repair, and provide a basis for further studies of wound age estimation.

中文翻译：

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使用微阵列和生物信息学分析深入了解骨骼肌挫伤后的分子谱变化。

日常生活中，肌肉损伤经常发生。然而，肌肉愈合的分子机制（部分取决于损伤程度）尚不清楚。本研究旨在研究轻度和重度肌肉挫伤后的基因表达谱，并提供有关修复过程分子机制的更多信息。33只大鼠随机分为对照组（n=3）、轻度挫伤组（n=15）和重度挫伤组（n=15）；挫伤组进一步分为五个亚组（受伤后 1、3、24、48 和 168 小时；每个亚组 n = 3）。通过微阵列分析，在轻度挫伤和重度挫伤中分别鉴定出总共 2,844 个和 2,298 个差异表达基因。通过对轻度和重度挫伤肌肉中 1,620 个共表达基因的分析，我们发现轻度和重度挫伤组之间功能模块和颞丛的基因谱相似；此外，这些基因显示出时间依赖性的表达模式，这使我们能够识别伤口年龄的有用标记。对功能模块和时间簇中的基因进行功能分析，并鉴定出每个模块-簇对中的中心基因。有趣的是，我们发现24-48小时下调的基因很大程度上与代谢过程有关，尤其是氧化磷酸化，而这方面的报道很少。这些结果提高了我们对肌肉修复分子机制的理解，并为伤口年龄估计的进一步研究提供了基础。