Ageing is marked by genomic instability, epigenetic drift, and transcriptional dysregulation, including DNA hypermethylation at regulatory genes in skeletal muscle. Exercise counteracts these effects by promoting hypomethylation at loci linked to metabolism and mitochondrial function. Binding sites for the Androgen Receptor (AR) and Estrogen Receptor (ESR1) are enriched among age- and exercise-responsive methylation regions, suggesting these hormone receptors mediate the molecular balance between ageing and adaptation.
This study rests on the hypothesis that ageing and exercise elicit sex-specific, opposing changes in AR and ESR1 binding affinity, transcriptional activity, and downstream pathways in skeletal muscle through epigenetic mechanisms. This study will map AR and ESR1 regulation across age, sex, and exercise using qPCR, Western blot, and chromatin profiling (ChIP-seq/CUT&RUN with ATAC-seq).This study will also use deep muscle proteomics from males and females pre- and post-exercise (Astral Orbitrap) to define receptor-associated networks through pathway analyses (IPA, GSEA, Cytoscape, Reactome); and model hormone- and epigenetic-driven regulation in testosterone- and estrogen-treated C2C12, hiPSC-derived, and primary human myocytes to test causal effects on receptor activity and signalling. We expect to identify sex-specific and inverse effects of ageing and exercise on AR and ESR1 expression, protein abundance, DNA methylation, and downstream pathways. These findings will clarify how AR and ESR1 shape the hormonal and epigenetic landscape of skeletal muscle and how their activity may counteract age-related declines in muscle structure and function. Ultimately, this work will provide a molecular framework for developing interventions that target AR and ESR1 to preserve muscle health, extend healthspan, and improve physical function in ageing populations.