Transcriptomic analysis of liver from grass carp (Ctenopharyngodon idellus) exposed to high environmental ammonia reveals the activation of antioxidant and apoptosis pathways
Transcriptomic analysis of liver from grass carp (Ctenopharyngodon idellus) exposed to high environmental ammonia reveals the activation of antioxidant and apoptosis pathways
复制标题
DOI：
10.1016/j.fsi.2017.02.037
复制
发表时间：
2017-04-01
影响因子：
4.7
通讯作者：
Lin, Li
中科院分区：
文献类型：
--
作者：
Jin, Jiali;Wang, Yao;Lin, Li
水体系统中氨浓度过高，对水生动物的健康造成不利影响。然而，氨中毒的机制尚不清楚。为了更好地了解氨对鱼类的毒性作用机制，本研究以草鱼幼鱼为研究对象。采用RNA高通量测序技术，对模拟高环境氨（HEA）的2 mM NH4HCO3水中暴露8 h后鱼肝脏中提取的总RNA进行了分析。对照组和2 mM HEA组分别获得49,971,114和53,826,986个clean reads，其中有911个不同表达基因（deg），其中上调基因563个，下调基因348个。另外，对10个deg进行了定量PCR验证。这些deg参与了与氧化应激或细胞凋亡相关的几种途径。进一步分析HEA对草鱼肝脏氧化应激、组织病理学和细胞凋亡的影响，发现了有趣的结果。活性氧（ROS）含量和超氧化物歧化酶（SOD）活性升高，过氧化氢酶（CAT）活性降低，这可能与DEGs及FOXO信号通路等相关途径有关。组织病理学和TUNEL检测结果证实HEA诱导了肝脏细胞凋亡。结合转录组学实验结果，c-Myc-Bax-caspase9凋亡通路可能参与氨胁迫诱导草鱼肝脏凋亡。(C) 2017 Elsevier Ltd.版权所有。
High concentration of ammonia in aquatic system leads to detrimental effects on the health of aquatic animals. However, the mechanism underlying ammonia-induced toxicity is still not clear. To better understand the mechanism of ammonia toxicity effects on fish, juvenile grass carp was employed in the present study. RNA high-throughput sequencing technique was applied to analyze the total RNAs extracted from the liver of fish after 8 h post exposure to the water containing 2 mM NH4HCO3 which experimentally mimicked the high environmental ammonia (HEA). A total of 49,971,114 and 53,826,986 clean reads were obtained in control and 2 mM HEA group, respectively, in which there were 911 differently expressed genes (DEGs) including 563 up-regulated and 348 down-regulated genes. In addition, 10 DEGs were validated by quantitative PCR. These DEGs were involved in several pathways related with oxidative stress or apoptosis. Further analysis on oxidative stress, histopathology and cellular apoptosis in grass carp liver after HEA exposure revealed interesting findings. Increased reactive oxygen species (ROS) content and superoxide dismutase (SOD) activity together with the decreased catalase (CAT) activity were detected, which may be effected by DEGs and related pathways such as FOXO signaling pathway. The histopathology and TUNEL assays results confirmed that apoptosis was induced in liver when fish had suffered HEA. Combined with the results of transcriptomic experiments, c-Myc-Bax-caspase9 apoptosis pathway could be involved in grass carp liver apoptosis induced by ammonia stress. (C) 2017 Elsevier Ltd. All rights reserved.