病毒和细菌共诱导的多效型牙鲆microRNA及其功能解析和应用探索

MicroRNA (miRNA) is a type of non-coding RNA that plays an important role in post-transcriptional regulation. In previous work, we studied the expression of Japanese flounder miRNA during the infection process of megalocytivirus, a severe fish virus. As a result, we identified 121 virus-induced flounder miRNA and found that some virus-induced miRNA could also be induced by the infection of fish bacterial pathogens. Since virus and bacteria are the main pathogenic organisms faced by cultured fish and the complexity of the pathogen species poses difficulties for the research of fish disease and the development of disease control techniques, the study that aims simultaneously at multiple viral and bacterial pathogens would be valuable. Based on this rationale, we in this proposal plan to screen from the 121 megalocytivirus-induced miRNA the ones that can be induced by one or multiple bacteria commonly pathogenic to cultured fish, whereby obtaining miRNA with multi-effect against both viral and bacterial pathogens. We will then examine the function and regulation mechanism of the selected miRNA and explore the potentials of applying these miRNA to the prevention of diseases associated with viral and bacterial infection. The design of our study is novel, and the results will provide guidance and targets for fish disease control that aims at multiple pathogens by one shot.

MicroRNA（miRNA)是一类非编码RNA，其作用是调控转录后基因表达。申请人在前期工作中以海水经济鱼种牙鲆为宿主，研究了鱼类重要病毒肿大细胞病毒感染时宿主miRNA的表达，由此获得了121个病毒诱导的牙鲆miRNA，并且发现某些病毒诱导的miRNA也能被鱼类致病性细菌所诱导。由于细菌和病毒是鱼类所面对的主要病原体系，其种类复杂性制约了相关病害的理论研究和防控技术发展，因此同时针对病毒和细菌的研究方式具有重要理论和应用意义。基于此，申请人拟在本项目中利用前期研究所发现的百余个病毒诱导的牙鲆miRNA，从中筛选不仅被病毒诱导而且也被病原菌诱导的miRNA，获得对病毒和细菌具有共靶向作用的多效型miRNA，解析其功能和调控机制，探索其在病毒和细菌病共防治中的应用性。项目不仅在设计上具有创新性，而且其结果将为“一箭双/多雕”式的鱼类病害防控模式提供新的思路和靶点。

MicroRNA（miRNA)是一类非编码RNA，其作用是调控转录后基因表达。我们在前期工作中研究了肿大细胞病毒感染牙鲆时宿主miRNA的表达，获得了121个病毒诱导的miRNA，发现某些miRNA也能被鱼类致病菌所诱导。基于此，本项目的研究目标是系统筛选病毒-细菌共诱导的牙鲆miRNA，解析其功能和调控机制，探索其应用潜能。经过五年研究，项目系统筛选、鉴定了多个肿大细胞病毒和鱼类致病菌（迟缓爱德华氏菌、鳗弧菌和海豚链球菌）共诱导的牙鲆miRNA，确定了病毒-细菌共靶向性miRNA的靶基因，解析了靶基因的免疫功能，取得了系列新颖发现，包括发现pol-miR-194a通过其靶基因IRF7/TNFR2调控I型干扰素和NF-kB通路而参与抗感染免疫，pol-miR-182-5p和pol-miR-novel_171分别通过其靶基因PoS1PR1和PoFAM49B调控细胞凋亡及病原侵染，pol-miR-novel_547、pol-miR-3p-2和pol-miR-novel_642分别通过其靶基因PoPTEN、p53及CSF3调控自噬及病原侵染，pol-miR-363-3p、pol-miR-novel_395及pol-miR-150分别通过其靶基因PoUSP32、PUF60和LMP2L调控感染与免疫等。项目还探索了pol-miR-150等miRNA及靶基因的免疫防控应用潜能。在miRNA调控机制方面，项目研究发现了抗病毒免疫相关的内源竞争性circRNA-miRNA-mRNA调控网络，揭示了病原诱导的复杂miRNA-mRNA以及lncRNA-miRNA-mRNA免疫调控网络。项目研究获得2项授权国家发明专利，发表第一标注SCI论文15篇。综上所述，项目圆满完成了预期研究目标，研究结果提升了我们对鱼类miRNA调控机制与免疫功能的理解，也为鱼类病害防控提供了新思路。