ZnO NPs Impair the Viability and Function of Porcine Granulosa Cells Through Autophagy Regulated by ROS Production

The zinc oxide nanoparticles (ZnO NPs) is one of the most extensively utilized metal oxide nanoparticles in biomedicine, human food, cosmetics and livestock farming. However, growing evidence suggests that there is a potential risk for humans and animals because of the accumulation of ZnO NPs in cells, which leads to cell death through several different pathways. Nevertheless, the effects of ZnO NPs on porcine granulosa cells (PGCs) and how ZnO NPs regulate the follicular cells are unknown. In this study, we aimed to elucidate the role of ZnO NPs in the porcine ovary by using PGCs. Firstly, we identified the characterization of ZnO NPs used in this study and the results showed that the size of ZnO NPs was 29.0 nm. The results also demonstrated that ZnO NPs impaired cell viability and decreased steroid hormone secretion in PGCs. In addition, ZnO NPs induced reactive oxygen species (ROS) production, leading to oxidative stress of PGCs. Meanwhile, ZnO NPs also triggered autophagy in PGCs by increasing the ratio of LC3-II/LC3-I, along with the expression of SQSTM1 and ATG7. Finally, the results from N-acetylcysteine (NAC) addition suggested that ZnO NPs promoted autophagy through the enhancement of ROS production. In summary, this study demonstrates that ZnO NPs impair the viability and function of PGCs through autophagy, which is regulated by ROS production.