Abstract：
Aflatoxin B1 (AFB1) is extremely harmful to both humans and animals. Mitophagy is a selective process of self-elimination and has an important role in controlling mitochondrial quality. The present study aimed to investigate the effect of reactive oxygen species (ROS) accumulation on AFB1-induced mitophagy in HepG2 cells to provide a new perspective from which to design novel therapeutic strategies to treat AFB1 poisoning. ROS release was induced in HepG2 cells with AFB1 (10 μmol/L). Cell autophagy activity, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) levels, Parkin translocation and both the transcription and expression of mitophagy-related proteins were measured when N-acetyl-L-cysteine (NAC) partially decreased the ROS level, while the knockdown of nuclear factor erythroid 2-related factor 2 (Nrf2) resulted in a large accumulation of ROS. The results reveal that NAC pretreatment ameliorated the decline in both the MMP and the ATP levels while also activating phosphoglycerate mutase 5 (PGAM5)-PTEN-induced kinase 1 (PINK1)/Parkin, while the Nrf2 knockdown group exhibited the opposite trend. These results suggest that AFB1-induced mitophagy in HepG2 cells depends on ROS, and proper ROS activates mitophagy to play a protective role.
摘要：
黄曲霉毒素B1（AFB1）对人类和动物都非常有害。线粒体自噬是一种选择性的自我消除过程，在控制线粒体质量方面具有重要作用。本研究旨在探讨活性氧（ROS）积累对AFB1诱导的HepG2细胞线粒体自噬的影响，为设计新的AFB1中毒治疗策略提供新的视角。AFB1（10μmol/L）诱导HepG2细胞释放ROS。细胞自噬活性,线粒体膜电位（MMP），三磷酸腺苷（ATP）水平，当N-乙酰-L-半胱氨酸（NAC）部分降低ROS水平时，测量Parkin易位以及线粒体自噬相关蛋白的转录和表达，而核因子红系2相关因子2（Nrf2）的敲除导致ROS的大量积累。结果表明，NAC预处理改善了MMP和ATP水平的下降，同时还激活了磷酸甘油酸变位酶5（PGAM5）-PTEN诱导的激酶1（PINK1）/Parkin，而Nrf2敲除组表现出相反的趋势。这些结果表明AFB1诱导的HepG2细胞有赖于ROS,适当的ROS激活线粒体自噬发挥保护作用。
