Laboratory of Nutrition and Feed Formulation for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
Chongqing Key Laboratory of Animal Biology, School of Life Sciences, Chongqing Normal University, Chongqing 401331, China.
Int J Mol Sci. 2018 Sep 29;19(10):2980. doi: 10.3390/ijms19102980.
The present working hypothesis is that the Cu-induced changes in lipid metabolism may be mediated by miRNAs. Here, we describe the miRNA profile of the liver tissues of yellow catfish exposed to waterborne Cu, based on larger-scale sequencing of small RNA libraries. We identified a total of 172 distinct miRNAs. Among these miRNAs, compared to the control, mRNA expression levels of 16 miRNAs (miR-203a, 205, 1788-3p, 375, 31, 196a, 203b-3p, 2187-5p, 196d, 459-3p, 153a and miR-725, and two novel-miRNAs: chr4-1432, chr-7684) were down-regulated, and mRNA levels of miR-212 and chr20-5274 were up-regulated in Cu-exposed group. The functions of their target genes mainly involved ether lipid metabolism, glycerophospholipid metabolism, linoleic acid metabolism and α-linolenic acid metabolism. Cu exposure inhibited the expression of miR-205, whose predicted target genes were enriched in the pathway of lipid metabolism, including , , , , and . These potential target genes were further verified by Dual-luciferase reporter gene assay. Using primary hepatocytes of yellow catfish, Cu incubation down-regulated miR-205 expression, and increased TG contents and FAS activity. LXR antagonist effectively ameliorate the Cu-induced change of TG content and FAS activity. These data suggest that down-regulation of the miRNA-205 may be an important step in Cu-induced changes in lipid metabolism in yellow catfish.
目前的工作假设是，Cu 诱导的脂质代谢变化可能是由 miRNAs 介导的。在这里，我们根据更大规模的小 RNA 文库测序，描述了暴露于水相 Cu 的黄颡鱼肝组织中的 miRNA 谱。我们总共鉴定了 172 个不同的 miRNAs。在这些 miRNAs 中，与对照组相比，16 个 miRNAs（miR-203a、205、1788-3p、375、31、196a、203b-3p、2187-5p、196d、459-3p、153a 和 miR-725，以及两个新的-miRNAs：chr4-1432、chr-7684）的 mRNA 表达水平下调，而 miR-212 和 chr20-5274 的 mRNA 表达水平上调。其靶基因的功能主要涉及醚脂质代谢、甘油磷脂代谢、亚油酸代谢和α-亚麻酸代谢。Cu 暴露抑制了 miR-205 的表达，其预测的靶基因富集在脂质代谢途径中，包括 、 、 、 、 和 。这些潜在的靶基因通过双荧光素酶报告基因检测进一步验证。使用黄颡鱼原代肝细胞，Cu 孵育下调 miR-205 的表达，增加 TG 含量和 FAS 活性。LXR 拮抗剂有效改善了 Cu 诱导的 TG 含量和 FAS 活性的变化。这些数据表明，miR-205 的下调可能是 Cu 诱导黄颡鱼肝脂质代谢变化的重要步骤。
