Transcriptional control of training adaptation in skeletal muscle

Skeletal muscle has an enormous plastic potential and adapts to various stimuli such as mechanical stress, nutrients and hormones. While morphological changes observed in endurance trained muscles are well described, the molecular underpinnings of training adaptation is poorly understood. Therefore, the aim of our study was to define the molecular signature of a trained muscle and unravel the transcriptional responses of untrained and trained muscles to an acute bout of endurance exercise. Our results reveal that even though at baseline, the transcriptome of trained and untrained muscles is very similar, training status substantially affects the transcriptional response to an acute challenge, both quantitatively and qualitatively. Therefore, we provide novel insights into the complex molecular processes that are induced in response to exercise in a temporal- and training status-dependent manner. In addition, our study reveals that the epigenetic landscape contributes to the transcriptional memory of a trained muscle. Overall design: Quadriceps muscle RNA-seq of wildtype and PGC-1alpha muscle-specific knockout and transgenic mice; either in sedentary condition, after 4 weeks of training or after an acute bout of exhaustion exercise (untrained or trained) , 28 groups, 5 replicates/mice per group