Liu Qian, Xu Cheng, Ji Guixiang, Liu Hui, Mo Yiqun, Tollerud David J, Gu Aihua, Zhang Qunwei
State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
Nanjing Institute of Environmental Sciences, Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Ministry of Environmental Protection, Nanjing 210042, China.
Toxicol In Vitro. 2016 Sep;35:131-8. doi: 10.1016/j.tiv.2016.05.017. Epub 2016 May 28.
Environmental exposure to nanomaterials is inevitable as nanomaterials become part of our daily life, and as a result, nanotoxicity research is gaining attention. Most investigators focused on the effects of zinc oxide nanoparticles (ZnO NPs) on human health, while limited information was available on the male reproductive system. Herein, mouse Sertoli cell line (TM-4) and spermatocyte cell line (GC2-spd) were used as in vitro models to explore the reproductive effects of ZnO NPs at sublethal dose and its underlying mechanisms. Cells were treated with different concentrations of ZnO NPs. By cell viability assay, a dose of 8μg/mL was found as a sublethal dose and increased the ROS levels in both cells. The decreased glutathione level and increased MDA level were also found in ZnO NPs treated group. In TM4 cells, the expressions of BTB proteins (ZO-1, occludin, claudin-5, and connexin-43) were lower in the ZnO NPs group. The increased cell permeability and increased TNF-α secretion were also observed in ZnO NPs group. In GC2-spd cells, S phase arrest and DNA damage occurred in ZnO NPs group, which could be partially rescued by NAC. Our findings demonstrated that exposure to ZnO NPs induced ROS generation, caused DNA damage of germ cells, and down-regulated the expression of BTB proteins in Sertoli cells which could compromise the integrity of the blood-testis barrier. All these contributed to the male reproductive cytotoxic effects of ZnO NPs that could be partially rescued by anti-oxidants.
随着纳米材料成为我们日常生活的一部分，环境暴露于纳米材料中不可避免，因此，纳米毒性研究日益受到关注。大多数研究人员关注氧化锌纳米颗粒（ZnO NPs）对人类健康的影响，而关于男性生殖系统的信息有限。在此，小鼠支持细胞系（TM-4）和精母细胞系（GC2-spd）被用作体外模型，以探讨亚致死剂量的ZnO NPs的生殖效应及其潜在机制。细胞用不同浓度的ZnO NPs处理。通过细胞活力测定，发现8μg/mL的剂量为亚致死剂量，并增加了两种细胞中的活性氧水平。在ZnO NPs处理组中还发现谷胱甘肽水平降低和丙二醛水平升高。在TM4细胞中，ZnO NPs组中血睾屏障蛋白（ZO-1、闭合蛋白、claudin-5和连接蛋白-43）的表达较低。在ZnO NPs组中还观察到细胞通透性增加和TNF-α分泌增加。在GC2-spd细胞中，ZnO NPs组发生S期阻滞和DNA损伤，NAC可部分挽救这种损伤。我们的研究结果表明，暴露于ZnO NPs会诱导活性氧生成，导致生殖细胞DNA损伤，并下调支持细胞中血睾屏障蛋白的表达，这可能会损害血睾屏障的完整性。所有这些都导致了ZnO NPs对男性生殖的细胞毒性作用，抗氧化剂可部分挽救这种作用。
