Title: Resveratrol ameliorates liver fibrosis by inhibiting ATF4 to regulate glutamine metabolism in hepatic stellate cells

Resveratrol has been shown to mitigate liver fibrosis by inhibiting the activation of hepatic stellate cells (HSCs). However, the precise mechanisms remain incompletely understood. Resveratrol demonstrates therapeutic potential in alleviating liver fibrosis by promoting HSC Ferroptosis through the dual regulation of endoplasmic reticulum stress (ERS) and glutamine metabolism, as shown by in vivo and in vitro investigations. In carbon tetrachloride (CCl₄) induced fibrotic mice, resveratrol significantly attenuated liver injury, extracellular matrix (ECM) deposition, and Collagen synthesis. Cellular experiments revealed its dose-dependent inhibition of HSC activation via glutathione (GSH) depletion, iron accumulation, and downregulation of GSH peroxidase 4 (GPX4), with Ferroptosis inhibitor Ferrostatin-1 (Fer-1) reversing these effects. Mechanistically, resveratrol suppressed activating transcription factor 4 (ATF4) -mediated ERS signaling, subsequently reducing alanine-serine-cysteine transporter 2 (ASCT2) dependent glutamine uptake essential for GSH biosynthesis. Genetic manipulation experiments confirmed the central regulatory role of ATF4, whose overexpression counteracted resveratrol's effects, while ATF4 knockdown or Jumonji domain-containing protein D3 (JMJD3) inhibition epigenetically silenced ASCT2 transcription through enhanced trimethylation of histone H3 at lysine 27 (H3K27me3). These findings revealed a novel pathway by which resveratrol induces HSC Ferroptosis through metabolic and epigenetic regulation, offering a multi-targeted strategy against hepatic fibrosis that bridges amino acid metabolism, redox homeostasis, and chromatin remodeling processes.

Endoplasmic reticulum stress; Ferroptosis; Glutamine metabolism; Hepatic stellate cells; Resveratrol.