Sun Ying, Feng Long, Li Jiansheng, Xu Huaming, Mei Xue, Feng Lingyan, Sun Huijuan, Gao Jianfeng, Zhang Xiaoli
Basic Medicine College, Henan University of Chinese Medicine, Zhengzhou, Henan, China.
Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, Henan, China.
J Cell Physiol. 2019 Sep;234(9):15686-15697. doi: 10.1002/jcp.28222. Epub 2019 Jan 29.
Enterovirus 71 (EV71) is a small, nonenveloped icosahedral RNA virus and is the predominant causative pathogen of hand-foot-and-mouth disease. Recently, microRNAs (miRNAs) are reported to play important roles in the pathogenesis of EV71 replication. This study investigated the role of miR-545 in the EV71 replication and explored the underlying molecular mechanisms. We showed that miR-545 was upregulated in the EV71-infected human embryonic kidney (HEK) 293 cells and rhabdomyosarcoma (RD) cells. Overexpression of miR-545 promoted the viral replication of EV71 and attenuated the inhibitory effects of EV71 on cell viability in HEK293 and RD cells; while knockdown of miR-545 significantly suppressed the EV71 replication in these two cell lines. Bioinformatics analysis and luciferase reporter assay showed that miR-545 directly targeted the 3'untranslated region of phosphatase and tensin homolog (PTEN) and tumor necrosis factor receptor-associated factor 6 (TRAF6) in HEK293 cells. Furthermore, miR-545 negatively regulated the messenger RNA (mRNA) and protein expression of PTEN and TRAF6. The mRNA and protein expression of PTEN and TRAF6 was also suppressed by EV71 infection, which was attenuated by miR-545 knockdown in HEK293 cells. Overexpression of PTEN and TRAF6 both suppressed the EV71 replication in HKE293 cells, and also attenuated the enhanced effects of miR-545 overexpression on the EV71 replication in HEK293 cells. Collectively, our study for the first time showed that miR-545 had an enhanced effect on the EV71 replication in HEK293 and RD cells. Further mechanistic results indicated that miR-545 promoted EV71 replication at least partly via targeting PTEN and TRAF6.
肠道病毒71型（EV71）是一种小型、无包膜的二十面体RNA病毒，是手足口病的主要致病病原体。最近，有报道称微小RNA（miRNA）在EV71复制的发病机制中发挥重要作用。本研究调查了miR-545在EV71复制中的作用，并探索其潜在的分子机制。我们发现，在EV71感染的人胚肾（HEK）293细胞和横纹肌肉瘤（RD）细胞中，miR-545表达上调。miR-545的过表达促进了EV71的病毒复制，并减弱了EV71对HEK293和RD细胞活力的抑制作用；而敲低miR-545则显著抑制了这两种细胞系中EV71的复制。生物信息学分析和荧光素酶报告基因检测表明，miR-545在HEK293细胞中直接靶向磷酸酶和张力蛋白同源物（PTEN）以及肿瘤坏死因子受体相关因子6（TRAF6）的3'非翻译区。此外，miR-545负向调节PTEN和TRAF6的信使核糖核酸（mRNA）和蛋白质表达。PTEN和TRAF6的mRNA和蛋白质表达也受到EV71感染的抑制，而在HEK293细胞中敲低miR-545可减弱这种抑制作用。PTEN和TRAF6的过表达均抑制了HKE293细胞中EV71的复制，并且也减弱了miR-545过表达对HEK293细胞中EV71复制的增强作用。总体而言，我们的研究首次表明，miR-545对HEK293和RD细胞中EV71的复制具有增强作用。进一步的机制研究结果表明，miR-545至少部分通过靶向PTEN和TRAF6促进EV71复制。
