Xiangyang No.1 People's Hospital and Hubei University of Medicine, Xiangyang, Hubei Province, China.
College of Resources and Environment Qingdao Agricultural Unviersity, Qingdao, China.
Virol J. 2020 Feb 5;17(1):21. doi: 10.1186/s12985-020-1284-8.
Human enterovirus 71 (EV-A71) is a non-enveloped virus that has a single stranded positive sense RNA genome. In a previous study, we showed that miR-876-5p upregulation was observed in the serum of patients with severe EV-A71 infection. Micro-876-5p (miR-876-5p) is a circulating miRNA that can be identified to modulate EV-A71 infections through both in vitro and in vivo studies. However, the regulatory mechanisms that involve miR-876-5p in the EV-A71 infection cycle remain unclear.
We demonstrated that miR-876-5p facilitated EV-A71 replication and expression by overexpression and knocking-down of miR-876-5p through the transfection of miR-876-5p plasmid and miR-876-5p inhibitor. Although miR-876-5p suppressed CREB5 expression, luciferase reporter assay confirmed this. We also evaluated the role of miR-876-5p in the EV-A71 infection cycle by CREB5 mediated by transfection with an anti-miR-876-5P inhibitor or in combination with an si-CREB5 plasmid.
MicroR-876-5p was upregulated in EV-A71-infected neuroblastoma cells. Overexpression of miR-876-5p or knockdown of cyclic-AMP responsive element binding protein 5 (CREB5) promoted EV-A71 replication. The downregulation of miR-876-5p inhibited the accumulation of viral RNA and the production of viral proteins. Interestingly, CREB5 overexpression also suppressed EV-A71 replication. Our in vitro studies reveal that miR-876-5p directly targets CREB5. Finally, downregulation of CREB5 protein abated the inhibitory effect of anti-miR-876-5p and induced inhibitory effect of EV-A71 replication.
Our results suggest that intracellular miR-876-5p promotes EV-A71 replication indirectly by targeting the host CREB5 protein.
人类肠道病毒 71 型（EV-A71）是一种无包膜病毒，具有单链正链 RNA 基因组。在之前的研究中，我们发现在重症 EV-A71 感染患者的血清中观察到 miR-876-5p 的上调。Micro-876-5p（miR-876-5p）是一种循环 miRNA，可以通过体外和体内研究来调节 EV-A71 感染。然而，miR-876-5p 参与 EV-A71 感染周期的调节机制尚不清楚。
我们通过转染 miR-876-5p 质粒和 miR-876-5p 抑制剂过表达和敲低 miR-876-5p，证明了 miR-876-5p 促进 EV-A71 的复制和表达。尽管 miR-876-5p 抑制了 CREB5 的表达，但荧光素酶报告基因检测证实了这一点。我们还通过转染抗 miR-876-5p 抑制剂或与 si-CREB5 质粒联合，评估了 miR-876-5p 在 EV-A71 感染周期中的作用。
MicroR-876-5p 在 EV-A71 感染的神经母细胞瘤细胞中上调。miR-876-5p 的过表达或 CREB5 的敲低促进了 EV-A71 的复制。miR-876-5p 的下调抑制了病毒 RNA 的积累和病毒蛋白的产生。有趣的是，CREB5 的过表达也抑制了 EV-A71 的复制。我们的体外研究表明，miR-876-5p 可以直接靶向 CREB5。最后，下调 CREB5 蛋白减弱了抗 miR-876-5p 的抑制作用，并诱导了 EV-A71 复制的抑制作用。
我们的结果表明，细胞内 miR-876-5p 通过靶向宿主 CREB5 蛋白间接促进 EV-A71 的复制。
