Bai Yuntao, Jiang Li-Ping, Liu Xiao-Fang, Wang Dong, Yang Guang, Geng Cheng-Yan, Li Qiujuan, Zhong Lai-Fu, Sun Qinghua, Chen Min
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, Ohio, USA; Department of Food Nutrition and Safety, Dalian Medical University, No. 9, West Segment of South Lvshun Road, Dalian, 116044, Liaoning, China.
Environ Toxicol. 2015 May;30(5):530-7. doi: 10.1002/tox.21929. Epub 2013 Dec 6.
We hypothesize that citreoviridin (CIT) induces DNA damage in human liver-derived HepG2 cells through an oxidative stress mechanism and that N-acetyl-l-cysteine (NAC) protects against CIT-induced DNA damage in HepG2 cells. CIT-induced DNA damage in HepG2 cells was evaluated by alkaline single-cell gel electrophoresis assay. To elucidate the genotoxicity mechanisms, the level of oxidative DNA damage was tested by immunoperoxidase staining for 8-hydroxydeoxyguanosine (8-OHdG); the intracellular generation of reactive oxygen species (ROS) and reduced glutathione (GSH) were examined; mitochondrial membrane potential and lysosomal membranes' permeability were detected; furthermore, protective effects of NAC on CIT-induced ROS formation and CIT-induced DNA damage were evaluated in HepG2 cells. A significant dose-dependent increment in DNA migration was observed at tested concentrations (2.50-10.00 µM) of CIT. The levels of ROS, 8-OHdG formation were increased by CIT, and significant depletion of GSH in HepG2 cells was induced by CIT. Destabilization of lysosome and mitochondria was also observed in cells treated with CIT. In addition, NAC significantly decreased CIT-induced ROS formation and CIT-induced DNA damage in HepG2 cells. The data indicate that CIT induces DNA damage in HepG2 cells, most likely through oxidative stress mechanisms; that NAC protects against DNA damage induced by CIT in HepG2 cells; and that depolarization of mitochondria and lysosomal protease leakage may play a role in CIT-induced DNA damage in HepG2 cells.
我们假设黄绿青霉素（CIT）通过氧化应激机制诱导人肝源性HepG2细胞中的DNA损伤，并且N-乙酰-L-半胱氨酸（NAC）可保护HepG2细胞免受CIT诱导的DNA损伤。通过碱性单细胞凝胶电泳试验评估CIT诱导的HepG2细胞中的DNA损伤。为阐明遗传毒性机制，通过对8-羟基脱氧鸟苷（8-OHdG）进行免疫过氧化物酶染色来检测氧化性DNA损伤水平；检测细胞内活性氧（ROS）的产生和还原型谷胱甘肽（GSH）；检测线粒体膜电位和溶酶体膜的通透性；此外，评估了NAC对HepG2细胞中CIT诱导的ROS形成和CIT诱导的DNA损伤的保护作用。在测试浓度（2.50 - 10.00 µM）的CIT下，观察到DNA迁移有显著的剂量依赖性增加。CIT使ROS水平、8-OHdG形成增加，并诱导HepG2细胞中GSH显著耗竭。在用CIT处理的细胞中还观察到溶酶体和线粒体的稳定性破坏。此外，NAC显著降低了HepG2细胞中CIT诱导的ROS形成和CIT诱导的DNA损伤。数据表明，CIT诱导HepG2细胞中的DNA损伤，很可能是通过氧化应激机制；NAC可保护HepG2细胞免受CIT诱导的DNA损伤；线粒体去极化和溶酶体蛋白酶泄漏可能在CIT诱导的HepG2细胞DNA损伤中起作用。
