Physiological glucocorticoid receptor activation programs key cell phenotypes and functional epigenomic patterns in human fibroblasts [EPIC]

Chronic environmental stress can profoundly impact cell and body function. While the underlying mechanisms are poorly understood, epigenetics has emerged as a key link between environment and health. The genomic effects of stress are thought to be mediated by the action of glucocorticoid stress hormones, primarily cortisol in humans, which act via the glucocorticoid receptor (GR). To dissect how physiological GR activation influences epigenetic and cell states, human fibroblasts underwent prolonged exposure to physiological stress levels of cortisol and/or a selective GR antagonist. Cortisol was found to drive robust changes in cell proliferation, migration, and morphology, which were abrogated by concomitant GR blockade. These GR-driven phenotypes were accompanied by widespread, yet genomic context-dependent, changes in DNA methylation and mRNA expression involving genes with known roles in cell proliferation and migration. These findings provide novel insights into how chronic stress-driven functional epigenomic patterns become established to shape key cell phenotypes. EPIC array data of 4 IMR 90 samples with 6 biological replicates each were analyzed: vehicle, cortisol, relacorilant, and cortisol + relacorilant.