SIRT3 Acetylation Regulates Mitophagy to Alleviate Deoxynivalenol-Induced Apoptosis in Porcine Alveolar Macrophages Cells

Deoxynivalenol (DON), a global mycotoxin contaminant, induces immunotoxicity in swine and humans by disrupting mitochondrial membrane integrity and activating mitophagy. SIRT3 plays an important role in regulating cell metabolism and various diseases. It also regulates apoptosis (caused by DON) by regulating the mitophagy pathway, but this pathway has not been studied yet. Gene knockout and overexpression of SIRT3 were performed for proteomics and acetylation modification. Therefore, in this study, PAM cells were selected as an in vitro model of DON (1.1 μg/mL) exposure for 24 h. The results showed that the knockout impaired mitochondrial antioxidant function, whereas overexpression improves damage stimulation. DON can also affect the metabolism of immune pathways, but SIRT3 can enrich these substances' metabolism. The results of the acetylation modification analysis showed that knockout affected the mRNA metabolism and others, while overexpression affected apoptosis and others. DON exposure caused fatty acid degradation, and altered MAPK signaling pathway. Knockout and overexpression of SIRT3 under DON exposure were enriched in PPAR, Ferroptosis pathway. Overexpression attenuated DON-induced mitophagy by reducing cellular ROS, as well as the expression of LC3, P62 and PINK1/Parkin. Finally, SIRT3 reduced cell apoptosis by reducing the expression of BAX and CASP3 and increasing the expression of BCL-2. These results indicated that SIRT3 could alleviate DON-induced cell damage by reducing apoptosis through the mitophagy pathway.