Lu Chun-Jiao, Jiang Xue-Feng, Junaid Muhammad, Ma Yan-Bo, Jia Pan-Pan, Wang Hua-Bin, Pei De-Sheng
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Chemosphere. 2017 Oct;184:795-805. doi: 10.1016/j.chemosphere.2017.06.049. Epub 2017 Jun 14.
Graphene oxide (GO) has widespread concerns in the fields of biological sciences and medical applications. Currently, studies have reported that excessive GO exposure can cause cellular DNA damage through reactive oxygen species (ROS) generation. However, DNA damage mediated response of the base excision repair (BER) pathway due to GO exposure is not elucidated yet. Therefore, we exposed HEK293T cells and zebrafish embryos to different concentrations of GO for 24 h, and transcriptional profiles of BER pathway genes, DNA damage, and cell viability were analyzed both in vitro and in vivo. Moreover, the deformation of HEK293T cells before and after GO exposure was also investigated using atomic force microscopy (AFM) to identify the physical changes occurred in the cells' structure. CCK-8 and Comet assay revealed the significant decrease in cell viability and increase in DNA damage in HEK293T cells at higher GO doses (25 and 50 μg/mL). Among the investigated genetic markers in HEK293T cells, BER pathway genes (APEX1, OGG1, CREB1, UNG) were significantly up-regulated upon exposure to higher GO dose (50 μg/mL), however, low exposure concentration (5, 25 μg/mL) failed to induce significant genetic induction except for CREB1 at 25 μg/mL. Additionally, the viscosity of HEK293T cells decreased upon GO exposure. In zebrafish, the results of up-regulated gene expressions (apex1, ogg1, polb, creb1) were consistent with those in the HEK293T cells. Taken all together, the exposure to elevated GO concentration could cause DNA damage to HEK293T cells and zebrafish embryos; BER pathway could be proposed as the possible inner response mechanism.
氧化石墨烯（GO）在生物科学和医学应用领域受到广泛关注。目前，研究报道过量暴露于GO可通过产生活性氧（ROS）导致细胞DNA损伤。然而，GO暴露介导的碱基切除修复（BER）途径的DNA损伤反应尚未阐明。因此，我们将HEK293T细胞和斑马鱼胚胎暴露于不同浓度的GO中24小时，在体外和体内分析了BER途径基因的转录谱、DNA损伤和细胞活力。此外，还使用原子力显微镜（AFM）研究了GO暴露前后HEK293T细胞的变形情况，以确定细胞结构中发生的物理变化。CCK-8和彗星试验显示，在较高的GO剂量（25和50μg/mL）下，HEK293T细胞的细胞活力显著降低，DNA损伤增加。在HEK293T细胞中研究的遗传标记物中，暴露于较高的GO剂量（50μg/mL）时，BER途径基因（APEX1、OGG1、CREB1、UNG）显著上调，然而，低暴露浓度（5、25μg/mL）除了25μg/mL的CREB1外，未能诱导显著的基因诱导。此外，GO暴露后HEK293T细胞的粘度降低。在斑马鱼中，基因表达上调（apex1、ogg1、polb、creb1）的结果与HEK293T细胞中的结果一致。综上所述，暴露于升高的GO浓度会导致HEK293T细胞和斑马鱼胚胎的DNA损伤；BER途径可能是潜在的内部反应机制。
