The role and regulatory mechanism of autophagy in hippocampal nerve cells of piglet damaged by deoxynivalenol

Deoxynivalenol (DON), a type B trichothecene mycotoxin mainly affects the health status of pigs and reduced their growth. This study aimed to determine the effects of PI3K/Akt/mTOR pathway on DON-induced autophagy of piglet hippocampal nerve cells (PHNCs), and the relationship between autophagy and apoptosis. The effects of DON on autophagy of PHNCs were examined by cell morphology, cell viability, apoptosis rate, electron microscopy, transient transfection of GFP-LC3 plasmid, immunofluorescence and expression of autophagy-related genes and proteins. The relationship between autophagy and cell apoptosis was analyzed by western blotting, CCK-8 and flow cytometry. The results indicated that, DON inhibited the proliferation of PHNCs and significantly changed cell morphology, and induced apoptosis and autophagy. The expression levels of LC3 protein and gene increased, while the expression levels of PI3K/Akt/mTOR pathway-related genes and proteins decreased, when the concentration of DON increased. Activation of autophagy significantly increased cell viability, reduced apoptosis rate, inhibits autophagy significantly, reduced cell activity and increased apoptosis rate. This data demonstrated that DON exerts certain toxic effect on PHNCs, induced apoptosis and autophagy. PI3K/Akt/mTOR signaling pathway plays a negative regulatory role in DON-induced autophagy of PHNCs. At the same time, autophagy plays a protective role in DON-induced PHNCs injury.