HIF-1α-associated macrophage metabolic reprogramming mediates intestinal injury induced by acrylamide and 5-hydroxymethylfurfural co-exposure.

Acrylamide (AA) and 5-hydroxymethylfurfural (HMF) are processing-derived contaminants that frequently co-occur in environmental and dietary exposure, yet the health effects of their co-exposure remain poorly understood. Here, we show that co-exposure to AA and HMF induces duodenal injury in mice, whereas neither toxin alone causes significant damage. Macrophage depletion using clodronate liposomes significantly attenuates this pathology, identifying macrophages as important mediators of the intestinal injury. Co-exposure promotes macrophage polarization toward a pro-inflammatory phenotype. Notably, direct exposure of intestinal epithelial cells to AA and HMF produces limited cytotoxicity. In contrast, conditioned medium from AA+HMF-treated macrophages compromises epithelial viability and barrier integrity in both intestinal epithelial cells and mouse intestinal organoids. These findings indicate that macrophage-mediated inflammatory responses, rather than direct epithelial toxicity, contribute substantially to AA+HMF-induced intestinal injury. Mechanistically, AA and HMF co-exposure triggers mitochondrial dysfunction and elevated mitochondrial reactive oxygen species (mtROS) production in macrophages, accompanied by enhanced glycolysis and hypoxia-inducible factor-1α (HIF-1α) activation. Pharmacological inhibition or genetic silencing of HIF-1α attenuates metabolic and inflammatory responses, while scavenging mtROS or iNOS inhibition reduces macrophage activation. Collectively, these findings reveal an immune-mediated mechanism underlying AA and HMF co-exposure-induced intestinal injury and highlight macrophage responses as a determinant of contaminant mixture toxicity.