【摘要】 ATF-7是具有亮氨酸拉链结构的转录激活因子,为了解其是否参与调控氧化石墨烯(GO)的致毒效应,以秀丽线虫为在体研究模型,通过运动行为、肠道活性氧簇(ROS)水平和寿命分析,评价atf-7 RNA干扰对秀丽线虫应答GO毒效应的影响;同时以qRT-PCR和Patf-7::mCherry转基因秀丽线虫检测GO对atf-7表达水平的影响.结果显示,GO暴露可以降低秀丽线虫头部摆动和身体弯曲频率,且运动行为的下降与GO暴露浓度呈正相关;atf-7干扰秀丽线虫对GO致毒效应更加敏感,0.1 mg/L GO就可导致头部摆动和身体弯曲频率显著下降(P <0.01);在GO暴露条件下,atf-7干扰秀丽线虫的平均寿命由13.54 d缩短到8.8 d,寿命缩短程度大于空载干扰组(P <0.01);atf-7干扰秀丽线虫在GO暴露条件下肠道ROS水平比未暴露情况下上升了3.33倍,而空载组肠道ROS水平上升了2.66倍,atf-7干扰秀丽线虫对GO所致肠道ROS的积累更加明显(P <0.01).GO暴露可以诱导秀丽线虫atf-7的表达水平,GO暴露组atf-7在转录水平和蛋白水平较对照组分别上调了164倍和200倍.因此,atf-7是秀丽线虫应对GO致毒效应中所必需的,秀丽线虫通过上调atf-7的表达以应对GO毒效应,对秀丽线虫进行atf-7干扰降低其表达水平可使秀丽线虫对GO致毒效应更加敏感.(图4表1参24)更多还原

【Abstract】 The atf-7 gene encodes the leucine zipper(bZIP) transcription factor, but its function in regulating the response to graphene oxide(GO) is still unclear. Caenorhabditis elegans was used as an assay system to investigate the in vivo function of atf-7 in response to GO. RNA interference in the in vivo expression of atf-7 was used to knockdown its expression.Subsequently, the locomotion behaviors, lifespan, reactive oxygen species(ROS) levels in the intestine, and the expression at the transcriptional and protein levels were analyzed in absence and presence of GO exposure. The results showed that the locomotion behaviors were reduced by GO in a concentration-dependent manner. The atf-7 RNAi strains were more susceptible to GO, resulting in a decrease of head thrashes and body bends in the concentration of 0.1 mg/L(P < 0.01). The decrease of mean lifespan was higher in the atf-7 RNAi strains(decrease from 13.54 days to 8.8 days) than those of the empty vector RNAi strains when treated with GO(P < 0.01). The atf-7 RNAi strains generated more ROS in the intestine after GO exposure, which was 3.33 times higher than without exposure, while ROS in the empty vector group increased by 2.66(P < 0.01). Under the condition of GO exposure, the expressions of atf-7 at the transcriptional and protein levels were up-regulated by 164-fold and200-fold, respectively. The transcription factor ATF-7 is vital for C. elegans to deal with the toxic effects caused by GO and the nematodes were more susceptible to GO when atf-7 was knockdown by RNAi.更多还原