Regulated RNA Splicing Response to Endurance Exercise - Abstract The role of exercise in improving health and fitness has become an increasingly important area of scientific research. The MoTrPAC multiomic rat endurance exercise training (EET) study has convincingly shown that the effects of exercise are pervasive throughout the body and these effects are found at all omic levels. The study measured the effects of up to eight weeks of EET on transcriptomic, epigenomic, proteomic and metabolomic features across up to 19 tissues in male and female rats. In order to fully understand the mechanisms by which exercise impacts the body and health, we need a whole body, multiomic model of the regulatory networks that drive EET-induced molecular changes. One critical aspect of gene regulation that was overlooked in the MoTrPAC rat data analyses is exercise-regulation of alternative mRNA splicing (AS). Initial studies of the acute human MoTrPAC data show dramatic regulation of AS by acute exercise in the limited tissues sampled in that study. This indicates that exercise-regulated splicing is an important mediator of the effects of exercise and motivates our proposed study of the effects of EET throughout the organism. We propose to develop a 19 tissue map of the AS landscape, both at baseline and in response to EET. This will be an unprecedented diversity of tissues with which to explore AS behavior. By integrating these results across omes, we can elucidate both what is changing in the AS landscape and how it affects downstream gene and protein activity. In addition, we can use epigenome and transcription factor activity analyses to identify the mechanisms underlying AS regulation. First, we will measure baseline un-exercised tissue specificity of AS events, and second, we will find differential AS events (DASs) in response to one, two, four, or eight weeks of EET. We will modify bioinformatic integration tools developed by our team to optimize integrated analysis of splicing and regulatory mechanisms, including PLIER to look for cross-tissue patterns of AS response to EET annotated to enriched pathways and MAGICAL to generate regulatory circuits of coordinated EET responses in chromatin accessibility or DNA methylation with DASs and enriched transcription factors. This knowledge will be a valuable resource for future AS analysis in general and, specifically, in studies of exercise. Because most of the tissues included in this study cannot be analyzed in human subjects, we will use these results as a foundation for future grant proposals seeking to connect the 19 tissue AS responses in rat to human understanding of the AS landscape.
