To date, there are limited and incomplete data on possible sex-based differences in fiber-types of skeletal muscle and their response to physical exercise. Adult healthy male and female mice completed a single bout of endurance exercise to examine the sex-based differences of the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), heat shock protein 60 (Hsp60), interleukin 6 (IL-6) expression, as well as the Myosin Heavy Chain (MHC) fiber-type distribution in soleus and extensor digitorum longus (EDL) muscles. Our results showed for the first time that in male soleus, a muscle rich of type IIa fibers, endurance exercise activates specifically genes involved in mitochondrial biogenesis such as PGC1 α1 isoform, Hsp60 and IL-6, whereas the expression of PGC1 α2 and α3 was significantly upregulated in EDL muscle, a fast-twitch skeletal muscle, independently from the gender. Moreover, we found that the acute response of different PGC1α isoforms was muscle and gender dependent. These findings add a new piece to the huge puzzle of muscle response to physical exercise. Given the importance of these genes in the physiological response of the muscle to exercise, we strongly believe that our data could support future research studies to personalize a specific and sex-based exercise training protocol.

中文翻译：

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对骨骼肌中 PGC1α 亚型进行单次运动后的性别差异：一项初步研究

迄今为止，关于骨骼肌纤维类型可能基于性别的差异及其对体育锻炼的反应的数据有限且不完整。成年健康雄性和雌性小鼠完成了一次耐力运动，以检查过氧化物酶体增殖物激活受体 γ 共激活因子 1 α (PGC1α)、热休克蛋白 60 (Hsp60)、白细胞介素 6 (IL-6) 的性别差异表达，以及比目鱼肌和趾长伸肌 (EDL) 肌肉中的肌球蛋白重链 (MHC) 纤维类型分布。我们的研究结果首次表明，在雄性比目鱼肌（富含 IIa 型纤维的肌肉）中，耐力运动特异性激活参与线粒体生物发生的基因，如 PGC1 α1 同种型、Hsp60 和 IL-6，而 PGC1 α2 和 α3 的表达是在 EDL 肌肉中显着上调，一种快速抽搐的骨骼肌，与性别无关。此外，我们发现不同 PGC1α 亚型的急性反应是肌肉和性别依赖性的。这些发现为肌肉对体育锻炼的反应这一巨大难题增添了新的一块。鉴于这些基因在肌肉对运动的生理反应中的重要性，我们坚信我们的数据可以支持未来的研究，以个性化特定的和基于性别的运动训练方案。