Department of Physical Education, Seoul National University, Seoul, South Korea.
Department of Sports Medicine, College of Health Science, CHA University, Pocheon, South Korea.
Aging (Albany NY). 2022 Apr 19;14(8):3337-3364. doi: 10.18632/aging.204024.
Skeletal muscles are made up of various muscle fiber type including slow and fast-twitch fibers. Because each muscle fiber has its own physiological characteristics, the effects of aging and exercise vary depending on the type of muscle fiber. We used bioinformatics screening techniques such as differentially expressed gene analysis, gene ontology analysis and gene set enrichment analysis, to try to understand the genetic differences between muscle fiber types. The experiment and gene expression profiling in this study used the soleus (SOL, slow-twitch muscle) and gastrocnemius (GAS, fast-twitch muscle). According to our findings, fatty acid metabolism is significantly up-regulated in SOL compared to GAS, whereas the glucose metabolism pathway is significantly down-regulated in SOL compared to GAS. Furthermore, apoptosis and myogenesis patterns differ between SOL and GAS. SOL did not show differences in apoptosis due to the aging effect, but apoptosis in GAS was significantly up-regulated with age. Apoptosis in GAS of old groups is significantly reduced after 4 weeks of aerobic exercise, but no such finding was found in SOL. In terms of myogenesis, exercise intervention up-regulated this process in GAS of old groups but not in SOL. Taken together, muscle fiber type significantly interacts with aging and exercise. Despite the importance of the interaction between these factors, large-scale gene expression data has rarely been studied. We hope to contribute to a better understanding of the relationship between muscle fiber type, aging and exercise at the molecular level.
骨骼肌由各种肌纤维类型组成，包括慢肌和快肌纤维。由于每种肌纤维都有其自身的生理特性，因此衰老和运动的影响因肌纤维类型而异。我们使用生物信息学筛选技术，如差异表达基因分析、基因本体分析和基因集富集分析，试图了解肌纤维类型之间的遗传差异。本研究中的实验和基因表达谱分析使用比目鱼肌（SOL，慢肌）和腓肠肌（GAS，快肌）。根据我们的发现，与 GAS 相比，脂肪酸代谢在 SOL 中显著上调，而与 GAS 相比，SOL 中的葡萄糖代谢途径显著下调。此外，SOL 和 GAS 之间的细胞凋亡和肌生成模式存在差异。由于衰老效应，SOL 中没有细胞凋亡的差异，但 GAS 中的细胞凋亡随年龄显著上调。4 周有氧运动后，老年组 GAS 中的细胞凋亡明显减少，但在 SOL 中没有发现这种现象。在肌生成方面，运动干预在上调老年组 GAS 中的这一过程，但在 SOL 中没有发现。总的来说，肌纤维类型与衰老和运动有显著的相互作用。尽管这些因素之间的相互作用很重要，但很少有大规模的基因表达数据进行研究。我们希望为更好地了解肌纤维类型、衰老和运动之间的分子水平关系做出贡献。
