Ma Junguo, Li Yuanyuan, Yao Lan, Li Xiaoyu
College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
Toxins (Basel). 2017 Jan 7;9(1):23. doi: 10.3390/toxins9010023.
In recent years, microRNAs (miRNAs) in toxicology have attracted great attention. However, the underlying mechanism of miRNAs in the cytotoxicity of microcystin-LR (MC-LR) is lacking. The objective of this study is to analyze miRNA profiling in HepG2 cells after 24 h of MC-LR-exposure to affirm whether and how miRNAs were involved in the cytotoxicity of MC-LR. The results showed that totally 21 and 37 miRNAs were found to be significantly altered in the MC-LR treated cells at concentrations of 10 and 50 μM, respectively, when compared to the control cells. In these two groups, 37,566 and 39,174 target genes were predicted, respectively. The further analysis showed that MC-LR-exposure promoted the expressions of has-miR-149-3p, has-miR-449c-5p, and has-miR-454-3p while suppressed the expressions of has-miR-4286, has-miR-500a-3p, has-miR-500a-5p, and has-miR-500b-5p in MC-LR-treated groups when compared to the control group. Moreover, the result of qPCR confirmed the above result, suggesting that these miRNAs may be involved in MC-LR-hepatotoxicity and they may play an important role in the hepatitis and liver cancer caused by MC-LR. The target genes for differentially expressed miRNAs in MC-LR treatment groups were significantly enriched to totally 23 classes of GO, in which three were significantly enriched in both 10 and 50 μM MC-LR groups. Moreover, the results of KEGG pathway analysis showed that MC-LR-exposure altered some important signaling pathways such as MAPK, biosynthesis of secondary metabolites, and pyrimidine and purine metabolism, which were possibly negatively regulated by the corresponding miRNAs and might play important role in MC-LR-mediated cytotoxicity in HepG2 cells.
近年来，毒理学中的微小RNA（miRNA）备受关注。然而，miRNA在微囊藻毒素-LR（MC-LR）细胞毒性中的潜在机制尚不清楚。本研究的目的是分析MC-LR暴露24小时后HepG2细胞中的miRNA谱，以确定miRNA是否以及如何参与MC-LR的细胞毒性。结果显示，与对照细胞相比，在10μM和50μM浓度的MC-LR处理细胞中，分别发现共有21个和37个miRNA发生了显著变化。在这两组中，分别预测到37566个和39174个靶基因。进一步分析表明，与对照组相比，MC-LR处理组中，MC-LR暴露促进了has-miR-149-3p、has-miR-449c-5p和has-miR-454-3p的表达，同时抑制了has-miR-4286、has-miR-500a-3p、has-miR-500a-5p和has-miR-500b-5p的表达。此外，qPCR结果证实了上述结果，表明这些miRNA可能参与MC-LR的肝毒性，并且它们可能在MC-LR引起的肝炎和肝癌中发挥重要作用。MC-LR处理组中差异表达miRNA的靶基因显著富集到总共23类GO，其中有3类在10μM和50μM MC-LR组中均显著富集。此外，KEGG通路分析结果表明，MC-LR暴露改变了一些重要的信号通路，如MAPK、次生代谢物的生物合成以及嘧啶和嘌呤代谢，这些通路可能受到相应miRNA的负调控，并且可能在MC-LR介导的HepG2细胞毒性中发挥重要作用。
