Mitochondrial Protease AFG3L2 Inhibits Ferroptosis of Intestinal Epithelial Cells through PPARA/GPX4 Signaling Pathway to Improve Experimental Enteritis

Abstract

The pathogenesis of Crohn disease (CD) remains unclear, with mitochondrial dysfunction and ferroptosis emerging as important contributors. However, the specific mechanisms linking mitochondria, ferroptosis, and CD are not well understood. Through bioinformatics analysis using the Gene Expression Omnibus database, AFG3L2 was identified as a key mitochondrial gene and subjected to functional enrichment and immune infiltration analyses. Lipopolysaccharide-induced NCM460 cells were used in vitro. Overexpression of AFG3L2 inhibited the release of inflammatory factors, enhanced antioxidant capacity, and reduced reactive oxygen species production. In addition, AFG3L2 overexpression activated the peroxisome proliferator-activated receptor-A (PPARA) signaling pathway and promoted the nuclear translocation of PPARA. As a downstream target of PPARA, glutathione peroxidase 4 (GPX4) transcriptional activity was regulated by PPARA. AFG3L2 facilitated the binding of PPARA to the GPX4 promoter region, thereby enhancing GPX4 transcription. Importantly, the regulation of GPX4 by AFG3L2 was dependent on the activation of PPARA. 2,4,6-Trinitrobenzenesulfonic acid–induced colitis in mice was used as an in vivo model. Overexpression of AFG3L2 preserved mitochondrial ultrastructure, suppressed intestinal inflammation, and promoted the expression of PPARA and GPX4. In summary, the results of this study reveal the protective role of the AFG3L2/PPARA/GPX4 axis in maintaining intestinal mucosal integrity and suggest it as a potential therapeutic target for CD.