Effects of a 8-week training on human skeletal muscle

Context: Exercise training is a plausible model for identification of molecular mechanisms that cause metabolic-related changes in human skeletal muscle. Objective: The goal was to explore the molecular basis of the adaptation of skeletal muscle to exercise training. Design and Intervention: Obese male subjects were subjected to an individualized supervised training program targeted in order to optimize lipid oxidation during 8 weeks. Main Outcome Measures: Primary outcome measures were gene expression profiling of skeletal muscle. Body composition, oral glucose tolerance test, Resting metabolic rate, respiratory quotient, maximal oxygen uptake and metabolic biochemistry were also assessed. Overall Design The obese (BMI 30-36) male volunteers (age 32-42) were asked to refrain from vigorous physical activity 48h before presenting to the clinical investigation centre, and ate a weight-maintaining diet consisting of 35% fat, 16% protein, and 49% carbohydrates two days before the experiment. Muscle biopsies of Vastus Lateralis weighing 60–100 mg were obtained using the Bergstrom technique, cleaned and snap-frozen in liquid nitrogen. Resting metabolic rate, respiratory quotient and maximal oxygen uptake were assessed. The subjects were investigated at baseline and after 8 weeks of supervised aerobic exercise training program consisting of daily sessions of 45-60 min of endurance exercise, 5 days a week, at least 48-72h after the last acute exercise bout. Skeletal muscle biopsies were obtained at the beginning and at the end of the protocol. Transcriptome analysis compared 8 subjects before vs. after training using arrays using a common reference design (Cy5 dye was incorporated into all muscle RNA samples, while a reference RNA pool made of the mix of commercial human liver, adipose tissue and skeletal muscle RNA was labelled with Cy3 dye (Applied Biosystems/Ambion, Foster City, USA)( and whole genome 4x44k oligonucleotide arrays (Agilent Technologies).

研究背景：运动训练是探究人类骨骼肌代谢相关变化分子机制的可靠模型。
研究目的：本研究旨在探索骨骼肌适应运动训练的分子基础。
设计与干预方案：纳入肥胖男性受试者，实施为期8周的个体化监督训练计划，以优化其脂质氧化过程。
主要结局指标：首要结局指标为骨骼肌基因表达谱分析；同时还对受试者身体成分、口服葡萄糖耐量试验、静息代谢率、呼吸商、最大摄氧量及代谢生化指标进行了检测。
整体研究设计：本研究纳入BMI为30~36的肥胖男性志愿者（年龄32~42岁），要求其在抵达临床研究中心前48小时内避免剧烈运动，并在实验前两日维持体重稳定饮食，该饮食成分为脂肪35%、蛋白质16%、碳水化合物49%。采用伯格斯托姆活检技术（Bergstrom technique）采集股外侧肌肌肉活检样本，样本重量为60~100 mg，经清洁处理后置于液氮中快速冷冻。同时检测受试者的静息代谢率、呼吸商及最大摄氧量。受试者分别在基线状态及为期8周的监督有氧训练结束后接受检测；该训练方案为每周5天，每日进行45~60分钟耐力运动，且每次检测均需在上一次急性运动结束后至少48~72小时进行。在实验方案的起始与结束阶段分别采集骨骼肌活检样本。转录组分析采用通用参考设计的芯片技术，对比8名受试者训练前后的基因表达情况：将Cy5荧光染料标记所有骨骼肌RNA样本，以商业来源的人肝、脂肪组织及骨骼肌RNA混合制成的参考RNA池采用Cy3荧光染料标记（应用生物系统/安百伦公司，美国福斯特城，Applied Biosystems/Ambion）；实验使用全基因组4x44k寡核苷酸芯片（安捷伦科技公司，Agilent Technologies）。