Effects of Acute Aerobic Exercise on Skeletal Muscle Transcriptomics in Lean vs Overweight/Obese Men

Acute aerobic exercise has been shown to improve skeletal muscle mitochondrial function and completeness of fatty acid ß-oxidation which contribute to improved insulin sensitivity. The effectiveness of acute exercise on improving mitochondrial adaptations, leading to improved insulin sensitivity, in overweight/obese (Ov/Ob) individuals is controversial. This study aimed to determine the effects of acute exercise on epigenetic regulation of genes involved in skeletal muscle mitochondrial adaptations in lean vs Ov/Ob men. Overall design: 30 men, aged 19-30 years, were recruited and divided into two groups: lean (BMI<25, 18.5- 24.1 kg/m2, n=15) and Ov/Ob (BMI=25, 25.5- 36.9 kg/m2, n=15). Vastus lateralis muscle biopsy samples were collected at rest, following an overnight fast (Pre; n=14 in lean Pre and n=15 in Ov/Ob Pre). Subjects then ingested a standardized high-carbohydrate breakfast (7 kcal/kg; 60% carbohydrate, 25% fat, 15% protein). Four hours later, they performed an acute bout of cycling exercise (50% VO2max, expending ~650 kcal) and vastus lateralis muscle biopsy samples were collected immediately after the exercise bout (Post; n=15 in lean Post and in Ov/Ob Post). RNA-seq via the Illumina platform was performed. Sequences were aligned using TopHat and differential gene expression determined using Cuffdiff.

已有研究表明，急性有氧运动可改善骨骼肌线粒体功能与脂肪酸β氧化完整性，进而提升胰岛素敏感性。然而，急性有氧运动对超重/肥胖（Overweight/Obese, Ov/Ob）人群线粒体适应性改善、从而提升胰岛素敏感性的效果尚存争议。本研究旨在探究急性有氧运动对瘦体型与超重/肥胖男性骨骼肌线粒体适应性相关基因表观遗传调控的影响。
研究设计：本研究招募了30名年龄在19~30岁之间的男性，将其分为两组：瘦体型组（身体质量指数<25 kg/m²，范围18.5~24.1 kg/m²，n=15）与超重/肥胖组（身体质量指数≥25 kg/m²，范围25.5~36.9 kg/m²，n=15）。受试者在隔夜空腹状态下于静息时采集股外侧肌活检样本（基线组，Pre；瘦体型组基线n=14，超重/肥胖组基线n=15）。随后受试者进食标准化高碳水早餐（热量为7 kcal/kg体重，其中碳水化合物占60%、脂肪占25%、蛋白质占15%）。四小时后，受试者进行一次急性骑行运动（强度为50%最大摄氧量（Maximal Oxygen Uptake, VO2max），总能耗约650 kcal），并于运动结束后即刻采集股外侧肌活检样本（运动后组，Post；瘦体型组与超重/肥胖组运动后样本量均为n=15）。采用Illumina测序平台进行RNA测序（RNA-seq）；使用TopHat工具完成序列比对，通过Cuffdiff分析差异基因表达情况。