CRISPR/Cas9-Mediated Knockout of CGNL1 Confers Resistance to Aflatoxin B1 in Porcine Intestinal Epithelial Cells via Suppressing ROS Generation

Aflatoxin B1 (AFB1) is a prevalent and highly toxic mycotoxin in the food and feed chain and can directly injure the intestinal epithelium. Yet, its upstream determinants linking epithelial stress to cytotoxicity remain insufficiently defined. Here, we used porcine intestinal epithelial IPEC-J2 cells to characterize AFB1-induced cytotoxic and transcriptomic responses and to determine the role of the tight-junction scaffold, Cingulin-like 1 (CGNL1), a candidate gene identified through genome-scale CRISPR knockout library screening. The results showed that AFB1 exposure reduced cell viability in a dose-dependent manner and induced oxidative stress. RNA-seq profiling analysis revealed broad transcriptional remodeling, with activation of inflammatory pathways (including NF-κB and JAK–STAT signaling). Based on our constructed CGNL1-knockout IPEC-J2 cell line (CGNL1-KO IPEC-J2) using CRISPR/Cas9, it was found that CGNL1 deficiency markedly alleviated AFB1-induced cytotoxicity and oxidative stress. Comparative transcriptomics analysis showed that CGNL1 knockout attenuated AFB1-triggered aberrant expression of some CGNL1-dependent AFB1-responsive genes related to immune response under AFB1 challenge. Together, these findings identify CGNL1 as a potential modulator of epithelial susceptibility to AFB1 and support its involvement in the regulation of toxin-induced oxidative response.