Department of Ecology, Jinan University, Guangzhou 510632, China.
Department of Ecology, Jinan University, Guangzhou 510632, China; Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China.
Environ Pollut. 2018 Feb;233:395-406. doi: 10.1016/j.envpol.2017.10.080. Epub 2017 Nov 5.
Diclofenac (DCF) has been recognized as an emerging contaminant in aquatic environments. Though many studies have investigated the toxic effects of DCF in human and mammals, limited information is available for the responses of genes associated with detoxification metabolisms in non-target aquatic organisms such as fish. In the present study, a small benthic fish Mugilogobius abei, was chosen as the test organism and the effects of DCF on detoxification-related genes at transcriptional level in M. abei were investigated. Partial cDNAs of pregnane-X-receptor (pxr), cytochrome P450 3A (cyp 3a) and alpha-gst were cloned firstly. The responses of cyp 1a, cyp 3a, alpha-gst and p-gp genes and associated microRNAs expressions were measured under different concentrations of DCF exposure (0.5, 5, 50, 500 μg/L) for 24 h and 168 h. Induction of cyp 1a, cyp 3a, alpha-gst, p-gp and pxr mRNA expressions was observed under DCF exposure for different time. Positive concentration-response relationships between DCF concentrations and cyp 1a as well as alpha-gst mRNA expression were observed under DCF exposure for 24 h. The similar trend between pxr mRNA expression and cyp 3a gene expression suggested the role of pxr in regulation of its downstream detoxification genes involved in DCF detoxification in M. abei. The negative correlation between miR-27a and p-gp expression under DCF exposure for 24 h indicated the role of miRNA in post transcriptional regulation on detoxification-related genes mRNAs in M. abei exposed to DCF. Overall, DCF exposure, even at environmental levels, may interrupt the responses of the detoxification genes in M. abei, which may affect the response of the exposed organism to other pollutants. This work provides implications on the bio-monitoring and risk assessment of DCF in aquatic ecosystems by using of local native fish species.
双氯芬酸（DCF）已被视为水生环境中的一种新兴污染物。尽管许多研究已经调查了 DCF 对人类和哺乳动物的毒性影响，但对于非靶标水生生物（如鱼类）中与解毒代谢相关的基因的反应，可用的信息有限。在本研究中，选择小型底栖鱼类阿比鲫作为测试生物，并研究了 DCF 在转录水平上对阿比鲫解毒相关基因的影响。首先克隆了孕烷 X 受体（pxr）、细胞色素 P450 3A（cyp 3a）和α- GST 的部分 cDNA。在不同浓度的 DCF 暴露（0.5、5、50、500μg/L）下，测量了 Cyp1a、Cyp3a、α-GST 和 P-GP 基因及其相关 microRNAs 表达的反应，分别暴露 24 小时和 168 小时。在 DCF 暴露下，观察到 Cyp1a、Cyp3a、α-GST、P-GP 和 pxr mRNA 表达的诱导。在 24 小时 DCF 暴露下，观察到 Cyp1a 以及α-GST mRNA 表达与 DCF 浓度之间存在正浓度-反应关系。pxr mRNA 表达与 Cyp3a 基因表达之间的相似趋势表明，pxr 在调节其下游解毒基因参与阿比鲫中 DCF 解毒方面发挥作用。在 24 小时 DCF 暴露下，miR-27a 与 P-GP 表达之间的负相关表明，miRNA 在 DCF 暴露的阿比鲫解毒相关基因 mRNAs 的转录后调控中发挥作用。总之，即使在环境水平下，DCF 暴露也可能干扰阿比鲫解毒基因的反应，这可能会影响暴露生物对其他污染物的反应。这项工作为利用本地本地鱼类对水生生态系统中的 DCF 进行生物监测和风险评估提供了依据。
