GR/HDAC5-mediated AT2R silencing drives sex-specific adrenal dysfunction in caffeine-induced fetal growth restriction

Prenatal caffeine exposure (PCE) is associated with adverse pregnancy outcomes; however, the intrauterine programming mechanisms linking fetal growth restriction (FGR) to long-term adrenal dysfunction remain incompletely understood. Using a PCE rat model (caffeine administration on gestational days 9–20), we identified a distinct sexual dimorphism in adrenal steroidogenesis among FGR offspring. Female offspring exhibited sustained inhibition of adrenal steroidogenic capacity during both prenatal and postnatal periods, whereas male offspring showed intrauterine inhibition followed by postnatal recovery. PCE increased maternal and fetal circulating glucocorticoid (GC) levels, accompanied by a persistent reduction in angiotensin II type 2 receptor (AT2R) expression in female adrenal. High corticosterone (CORT) levels directly suppressed the expression of AT2R and steroidogenic genes in adrenocortical cells, while AT2R overexpression significantly reversed this high GC-induced inhibition. Combined in vivo and in vitro experiments revealed that the repression of AT2R was associated with histone H3 lysine 27 (H3K27) hypoacetylation at the AT2R promoter, coinciding with increased glucocorticoid receptor (GR) occupancy and enhanced GR–histone deacetylase 5 (HDAC5) interaction. Notably, GR knockdown or HDAC inhibition under high-GC conditions restored promoter H3K27ac levels and AT2R expression. In conclusion, PCE suppresses AT2R expression via the high GC-induced upregulation of the GR/HDAC5 signaling pathway, leading to epigenetic silencing of the AT2R promoter and subsequent sustained inhibition of adrenal steroidogenesis specifically in female FGR offspring. This study links the renin-angiotensin system (RAS) to adrenal developmental programming in FGR offspring, supporting further evaluation of AT2R as a potential intervention target.