Transcriptional Signatures of Human Skeletal Muscle in Response to Aerobic and Resistance Exercise

Aerobic and resistance exercise facilitate unique health- and functional-based adaptations in skeletal muscle. The precise cellular mechanisms through which these exercise-mode specific adaptations are realized remain to be completely understood. PURPOSE: Identify the transcriptional signatures of human skeletal muscle in response to acute aerobic and resistance exercise. METHODS: In a counter-balanced, cross over design, six healthy, recreationally active young men (26±1 yr; BMI: 24.9±2.7 kg·m-2) completed an acute bout of aerobic (AE, 40 min stationary cycling, 60-70% heart rate max) and resistance exercise (RE, 8 sets of 10 reps, 70% 1RM), separated by ∼1 week. Muscle biopsies (vastus lateralis) were obtained before exercise and at 1 and 4h after each exercise bout. Whole transcriptome next-generation RNA sequencing (HiSeq2500, Illumina) was performed on cDNA synthesized from skeletal muscle RNA. Sequencing data were analyzed using HTSeq and differential expression was identified using DESeq2 software. Genes with an adjusted p-value of <0.05 and ≥2-fold change (log2) from pre exercise were considered differentially expressed. RESULTS: At 1h postexercise, AE and RE elicited a similar number of up- (AE, 43; RE, 57) and down-regulated genes (AE, 1; RE, 1), including 36 genes that were common to both exercise modes. However, at 4h postexercise RE elicited a larger number of up- (AE, 156; RE, 353) and down-regulated genes (AE, 27; RE, 54), of which 143 genes were common between exercise modes. Over this postexercise time course 264 genes were preferentially up- (216 genes) or down-regulated (47 genes) only by RE whereas 40 genes were preferentially up- (21 genes) or down-regulated (19 genes) only by AE. CONCLUSION: These preliminary data highlight mutual and unique transcriptome responses to aerobic and resistance exercise that are likely to regulate, in part, the specific adaptive responses of skeletal muscle to these exercise modes. Further work is necessary to determine how these transcriptome profiles correlate to exercise-mode specific adaptations in skeletal muscle, and how they are impacted by age, gender, and clinical disease. Supported by intramural funds from ASU, TGen, and MU