Co-exposure to acrylamide and 5-hydroxymethylfurfural induces intestinal epithelial injury involving ferroptosis

Acrylamide (AA) and 5-hydroxymethylfurfural (HMF) are common food processing hazards frequently co-existing in thermally processed foods. Although both hazards have been reported to induce oxidative stress and cytotoxicity, their co-exposure effects on intestinal epithelial cells remain unclear. Here, we investigated the co-exposure effects and mechanisms of AA and HMF in intestinal epithelial IEC-6 cells. Co-exposure significantly reduced cell viability, disrupted redox homeostasis, and impaired mitochondrial function, as evidenced by glutathione depletion, increased lipid peroxidation, and mitochondrial membrane potential loss. Multiple lines of evidence supported the involvement of ferroptosis, including glutathione peroxidase 4 (GPX4) downregulation, intracellular iron accumulation, lipid reactive oxygen species (ROS) generation, and the protective effect of ferrostatin-1. Transcriptomic analysis further provided supportive evidence for ferroptosis-related pathways, which was further supported by decreased SLC7A11 expression. In parallel, alterations in autophagy-related markers and lysosomal function were observed, and chloroquine partially attenuated cellular injury, suggesting that impaired autophagic degradation may contribute to the cellular response to AA and HMF exposure. In addition, co-exposure induced nuclear accumulation of Nrf2 together with increased HO-1 expression, indicating activation of an adaptive antioxidant response to oxidative stress. Collectively, AA and HMF co-exposure induced intestinal epithelial injury associated with ferroptosis, accompanied by autophagy-lysosome dysfunction and activation of the Nrf2/HO-1 signaling. These findings improve our understanding of the cellular mechanisms underlying AA and HMF co-exposure in intestinal epithelial cells.