Cross-stressor mouse liver transcriptomics and cortisol-treated HepG2 cells reveal stressor-dependent oxidative-phosphorylation responses and GR/FOXO3/PPARγ-associated changes

Background/objective Chronic stress engages the hypothalamic-pituitary-adrenal axis and exposes the liver to repeated glucocorticoid signals, but hepatic transcriptional responses can differ among stress paradigms and cannot be assumed to mirror the direct response of hepatocyte-derived cells. This study integrated stressor-specific mouse liver transcriptomics with cortisol-exposed HepG2 experiments to characterize recurrent and context-dependent transcriptional changes and to test whether glucocorticoid receptor and FOXO3 perturbation attenuates selected cortisol-associated cellular phenotypes. Methods Nineteen bulk RNA-sequencing samples were analyzed as three separate contrasts with DESeq2. Cross-stressor recurrence was summarized descriptively from paradigm-specific effect directions and false discovery rates. HepG2 cells were exposed to final cortisol concentrations of 1, 5,10 μM, with additional groups receiving RU486 pretreatment or FOXO3-targeting small interfering RNA before 10 μM cortisol. Endpoints included CCK-8 cellular dehydrogenase activity, Annexin V/propidium iodide positivity, extracellular ATP, and selected GR/FOXO3/PPARγ-related proteins. Results Restraint, social defeat, and foot-shock stress yielded 2,246, 874, and 1610 significant retained count-matrix features, respectively. Fkbp5 increased in all three comparisons, whereas Pparg reached false discovery rate significance only after restraint stress. Oxidative-phosphorylation transcriptional enrichment was positive after restraint and foot-shock stress and negative after social defeat. In HepG2 cells, cortisol was associated with concentration-related decreases in CCK-8 signal and extracellular ATP and with increased apoptotic fraction. Cortisol was also associated with lower PPARγ, PGC-1α, TFAM, and COX IV abundance and a lower phospho-FOXO3/total FOXO3 ratio. RU486 pretreatment and FOXO3-targeting siRNA partially attenuated several of these changes. Conclusion The mouse liver data identified recurrent glucocorticoid-responsive transcription together with stressor-dependent metabolic programs, including divergent oxidative-phosphorylation and Pparg responses. The HepG2 experiments provide a complementary cellular layer in which cortisol-associated functional and protein changes were partially attenuated after GR antagonism or FOXO3 targeting. These findings support GR/FOXO3/PPARγ-related involvement while preserving the distinction between cross-stressor liver transcription and pharmacological cell-culture responses.