Han Jingjing, Chu Qing, Huo Ruixuan, Xu Tianjun
Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
Dev Comp Immunol. 2018 Jan;78:52-60. doi: 10.1016/j.dci.2017.09.011. Epub 2017 Sep 15.
MicroRNA-122 (miR-122) was originally identified in mouse and then lots of researches on miR-122 had been performed in mammals. However, the functional study of miR-122 were restricted in fish. In miiuy croaker, miR-122 is sensitive to poly(I:C) stimulation. In this study, a combination of bioinformatics and experimental techniques were used to investigate the functions of miR-122. DAK is a putative target gene of miR-122 which was predicted by bioinformatics, and further the luciferase reporter assays were used to confirm the target sites in DAK 3'untranslated region. The inhibiting effect of miR-122 mimics or pre-miR-122 on DAK presented the dose and time dependent manners, and the pre-miR-122 showed stronger inhibiting effect on DAK than the miR-122 mimics. Therefore, the miR-122 participate in regulating RIG-I-like receptors signaling pathway via inhibiting DAK which is the inhibitors of MDA5. The expression of miR-122 and DAK showed negative relationship in both miiuy croaker spleen and macrophages, which imply that miR-122 may regulate DAK at the post-transcriptional level. These results will enhance our understanding about the regulation of miRNAs on immune response in fish.
微小RNA-122（miR-122）最初是在小鼠中发现的，随后在哺乳动物中对miR-122进行了大量研究。然而，miR-122的功能研究在鱼类中受到限制。在大黄鱼中，miR-122对聚肌苷酸-聚胞苷酸（poly(I:C)）刺激敏感。在本研究中，采用生物信息学和实验技术相结合的方法来研究miR-122的功能。DAK是通过生物信息学预测的miR-122的一个假定靶基因，进一步使用荧光素酶报告基因检测来确认DAK 3'非翻译区的靶位点。miR-122模拟物或前体miR-122对DAK的抑制作用呈现剂量和时间依赖性，并且前体miR-122对DAK的抑制作用比miR-122模拟物更强。因此，miR-122通过抑制作为MDA5抑制剂的DAK参与调节视黄酸诱导基因I样受体信号通路。在大黄鱼脾脏和巨噬细胞中，miR-122和DAK的表达呈负相关，这表明miR-122可能在转录后水平调节DAK。这些结果将增强我们对鱼类中微小RNA对免疫反应调节的理解。
