Project description:The rates of obesity and sedentary lifestyle are on a dramatic incline, with associated detrimental health effects among women in particular. Although exercise prescriptions are useful for overcoming these problems, success can be hampered by differential responsiveness among individuals in cardiovascular fitness indices (i.e., improvements in strength, lipids, VO2max). Genetic factors appear to play an important role in determining this inter-individual variation in responsiveness. We performed microarray analyses on mRNA in whole blood from 60 sedentary women from a multi-ethnic cohort who underwent 12 weeks of exercise, to identify gene subsets that were differentially expressed between individuals who experienced the greatest and least improvements in fitness based upon a composite fitness score index. We identified 43 transcripts in 39 unique genes (FDR<10%; FC>1.5) whose expression increased the most in “high” versus “low” premenopausal female responders. Several (TIGD7, UQCRH, PSMA6, WDR12, TFB2M, USP15) have reported associations with fitness-related phenotypes. Bioinformatic analysis of the 39 genes identified 4 miRNAs whose expression has been linked to cardiovascular diseases (ANKRD22: miR-637, LRRFIP1: miR-132, PRKAR2B: miR-92a, RSAD2:miR-192). These 39 genes were enriched in 6 biological pathways, including the oxidative phosphorylation pathway (p=8.08 x 10-3). Two genes, LRRFIP1 and SNORD30, were also identified with lower expression in high responding postmenopausal women. In summary, we identified gene signatures based on mRNA analysis that define responsiveness to exercise in a largely minority-based female cohort. Importantly, this study validates several genes/pathways previously associated with exercise responsiveness and extends these findings with additional novel genes. We performed microarray analyses on mRNA in whole blood from 60 sedentary women from a multi-ethnic cohort who underwent 12 weeks of exercise, to identify gene subsets that were differentially expressed between individuals who experienced the greatest and least improvements in fitness based upon a composite fitness score index.