CAS Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Institute of Oceanology, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
CAS Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Institute of Oceanology, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
Fish Shellfish Immunol. 2020 Sep;104:439-446. doi: 10.1016/j.fsi.2020.06.016. Epub 2020 Jun 17.
In this study, we examined the function of a Japanese flounder (Paralichthys olivaceus) microRNA (miRNA), pol-miR-363-3p. We found that pol-miR-363-3p targets an ubiquitin-specific protease (USP), USP32. USP is a family of deubiquitinating enzymes essential to the functioning of the ubiquitin proteasome system. In mammals, USP32 is known to be associated with cancer and immunity. In fish, the function of USP32 is unknown. We found that flounder USP32 (PoUSP32) expression was detected in the major tissues of flounder, particularly intestine. In vitro and in vivo studies showed that pol-miR-363-3p directly regulated PoUSP32 in a negative manner by interaction with the 3'UTR of PoUSP32. Overexpression of pol-miR-363-3p or interference with PoUSP32 expression in flounder cells significantly blocked Streptococcus iniae infection. Consistently, in vivo knockdown of pol-miR-363-3p or overexpression of PoUSP32 enhanced dissemination of S. iniae in flounder tissues, whereas in vivo knockdown of PoUSP32 inhibited S. iniae dissemination. In addition, pol-miR-363-3p knockdown also significantly promoted the tissue dissemination of the viral pathogen megalocytivirus, which, as well as S. iniae, regulated pol-miR-363-3p expression. Together these results revealed an important role of pol-miR-363-3p in flounder immune defense against bacterial and viral infection.
在这项研究中，我们研究了日本牙鲆（Paralichthys olivaceus）microRNA（miRNA）pol-miR-363-3p 的功能。我们发现 pol-miR-363-3p 靶向一种泛素特异性蛋白酶（USP），USP32。USP 是泛素蛋白酶体系统发挥功能所必需的去泛素化酶家族。在哺乳动物中，USP32 与癌症和免疫有关。在鱼类中，USP32 的功能尚不清楚。我们发现牙鲆 USP32（PoUSP32）在牙鲆的主要组织中表达，特别是在肠中。体外和体内研究表明，pol-miR-363-3p 通过与 PoUSP32 的 3'UTR 相互作用，以负调控的方式直接调控 PoUSP32。pol-miR-363-3p 的过表达或干扰牙鲆细胞中 PoUSP32 的表达，可显著阻断鳗弧菌感染。一致地，体内敲低 pol-miR-363-3p 或过表达 PoUSP32 增强了鳗弧菌在牙鲆组织中的传播，而体内敲低 PoUSP32 则抑制了鳗弧菌的传播。此外，pol-miR-363-3p 的敲低也显著促进了病毒病原体虹彩病毒的组织传播，与鳗弧菌一样，虹彩病毒也调控 pol-miR-363-3p 的表达。这些结果表明，pol-miR-363-3p 在牙鲆对细菌和病毒感染的免疫防御中起着重要作用。
