Chu Qing, Sun Yuena, Bi Dekun, Cui Junxia, 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. 2017 Feb;67:117-125. doi: 10.1016/j.dci.2016.11.004. Epub 2016 Nov 7.
Toll-like receptors (TLRs) are a group of pattern-recognition receptors which play vital roles in ligand recognition and activation of the innate immune response. As an important member of TLRs family, TLR1 is mainly responsible for PAMPs from bacteria and play a pivotal role in sensing microbial products. Recent studies revealed that TLR1 could perceive LPS stimulation and transfer signals to activate the NF-κB pathway, whereas ligands and signaling pathway of TLR1 are still unclear in fish. Growing evidence has shown that miRNAs (microRNAs) play as negative regulators in controlling the diverse of biophysical and biochemical processes at the post-transcriptional level. In this study, we used a combination of bioinformatics and experimental techniques to exhibit that both miR-8159-5p and miR-217-5p were the direct negative regulators of TLR1 in miiuy croaker. Furthermore, dual-luciferase reporter assays showed that combining miR-8159-5p and miR-217-5p exhibited a greater negative regulatory effect on TLR1 than only miR-8159-5p or miR-217-5p. Additionally, we also demonstrated that the expression of both the two miRNAs could be up-regulated by LPS stimulation in either LPS-stimulation spleen tissue or LPS-treated cultured macrophage, which indicating that miR-8159-5p and miR-217-5p could be induced by LPS and may be as the negative regulators of TLR1 involved in the immune response to LPS stimulation. These results would enhance our understanding of the miRNA regulation in fish TLR signaling pathways.
Toll样受体（TLRs）是一组模式识别受体，在天然免疫反应的配体识别和激活中发挥着至关重要的作用。作为TLRs家族的重要成员，TLR1主要负责识别来自细菌的病原体相关分子模式（PAMPs），并在感知微生物产物中起关键作用。最近的研究表明，TLR1可以感知脂多糖（LPS）刺激并传递信号以激活核因子κB（NF-κB）通路，而鱼类中TLR1的配体和信号通路仍不清楚。越来越多的证据表明，微小RNA（miRNAs）在转录后水平控制各种生物物理和生化过程中作为负调节因子发挥作用。在本研究中，我们结合生物信息学和实验技术，证明了miR-8159-5p和miR-217-5p都是大黄鱼中TLR1的直接负调节因子。此外，双荧光素酶报告基因分析表明，与单独的miR-8159-5p或miR-217-5p相比，miR-8159-5p和miR-217-5p组合对TLR1具有更大的负调节作用。此外，我们还证明，在LPS刺激的脾脏组织或LPS处理的培养巨噬细胞中，LPS刺激均可上调这两种miRNA的表达，这表明miR-8159-5p和miR-217-5p可被LPS诱导，并且可能作为TLR1的负调节因子参与对LPS刺激的免疫反应。这些结果将加深我们对鱼类TLR信号通路中miRNA调控的理解。
