Primary human myotubes represent an alternative system to intact skeletal muscle for the study of human diseases related to changes in muscle energy metabolism. This work aimed to study if fatty acid and glucose metabolism in human myotubes in vitro were related to muscle of origin, donor gender, age, or body mass index (BMI). Myotubes from a total of 82 donors were established from three different skeletal muscles, i.e., musculus vastus lateralis, musculus obliquus internus abdominis, and musculi interspinales, and cellular energy metabolism was evaluated. Multiple linear regression analyses showed that donor age had a significant effect on glucose and oleic acid oxidation after correcting for gender, BMI, and muscle of origin. Donor BMI was the only significant contributor to cellular oleic acid uptake, whereas cellular glucose uptake did not rely on any of the variables examined. Despite the effect of age on substrate oxidation, cellular mRNA expression of pyruvate dehydrogenase kinase 4 (PDK4) and peroxisome proliferator–activated receptor gamma coactivator 1 alpha (PPARGC1A) did not correlate with donor age. In conclusion, donor age significantly impacts substrate oxidation in cultured human myotubes, whereas donor BMI affects cellular oleic acid uptake.

中文翻译：

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原代人类骨骼肌细胞的底物氧化受供体年龄的影响

原代人类肌管代表完整骨骼肌的替代系统，用于研究与肌肉能量代谢变化相关的人类疾病。这项工作旨在研究体外人肌管中的脂肪酸和葡萄糖代谢是否与肌肉来源、供体性别、年龄或体重指数 (BMI) 相关。从三种不同的骨骼肌（即股外侧肌、腹内斜肌和椎间肌）建立了来自总共 82 个供体的肌管，并评估了细胞能量代谢。多元线性回归分析表明，在校正性别、BMI 和肌肉来源后，供体年龄对葡萄糖和油酸氧化有显着影响。供体BMI是细胞油酸摄取的唯一重要贡献者，而细胞葡萄糖摄取不依赖于任何检查的变量。尽管年龄对底物氧化有影响，但丙酮酸脱氢酶激酶 4 (PDK4) 和过氧化物酶体增殖物激活受体 γ 共激活因子 1 α (PPARGC1A) 的细胞 mRNA 表达与供体年龄无关。总之，供体年龄显着影响培养的人类肌管中的底物氧化，而供体 BMI 影响细胞油酸摄取。