Zearalenone exposure impairs organelle function during porcine oocyte meiotic maturation

Zearalenone (ZEN) is one of the secondary metabolites of Fusarium and is regarded as a common contaminant of foodstuffs especially corn products. ZEN is considered to be cytotoxic, tissue toxic, genotoxic and reproductive toxic, which acts as a serious threat for humans and animals. In this study, we investigated the effects of ZEN on organelle function during porcine oocyte meiotic maturation. Our results showed that the expansion of cumulus granulosa cells and the extrusion of oocyte polar body were disturbed after ZEN exposure. Besides the aberrant mitochondrial distribution and impaired mitochondrial membrane potential after ZEN treatment during porcine oocyte maturation. We also found the fluorescence intensity of ER was decreased, and ZEN exposure altered ER stress level, showing with the reduced expression of GRP78. We also found that the spindle cortex distribution of Golgi apparatus was disrupted in ZEN-exposed oocytes, which was confirmed by the decreased level of GM130, moreover, our data also showed that Rab11-based vesical transport was disturbed, indicating the Golgi apparatus function was disrupted. Besides, the fluorescence intensity of lysosome was significantly increased, indicating the protein degradation and the potential autophagy occurrence after ZEN treatment. Thus, our results demonstrated that exposure to ZEN affected porcine oocyte meiotic maturation through its wide effects on organelle function for protein synthesis, transport and degradation.