Enterovirus 71 Suppresses miR-17-92 Cluster Through Up-Regulating Methylation of the miRNA Promoter.

Yuxuan Fu,Rui Zhang,Shijie Xu,Yu Jin,Zhiwei Wu,Huanru Wang,Li Zhang

doi:10.3389/fmicb.2019.00625

Abstract

Enterovirus 71 (EV71), the etiological agent of hand-foot-and-mouth disease, has become an increasing public health challenge worldwide. Accumulating evidence suggests that mammalian microRNAs (miRNAs), a class of non-coding RNAs of 18 to 24 nucleotides (nt) with important regulatory roles in cellular processes, participate in host antiviral defense and studies have suggested roles of miRNAs in EV71 replication and pathogenesis. In the current study, we reported that the expression of hsa-miR-17∼92 cluster was significantly downregulated during EV71 infection. Overexpression of hsa-miR-17∼92 inhibited, while inhibition of endogenous hsa-miR-17∼92 facilitated EV71 replication. We identified two sequences located at nt 3024 to 3038 and nt 2838 to 2862 of the EV71 (strain FY0805) genome as potential targets for hsa-miR-17-5p and miR-19a/b, respectively, which were validated by luciferase reporter assays and Western blot. Meanwhile, we identified DNA methylation as a novel mechanism of hsa-miR-17∼92 regulatory roles. The methylation of the miR-17-92 promoter was significantly increased (50%) upon EV71 infection, which appeared to be caused by the increased expression of DNMT3B but not DNMT1 and DNMT3A. Furthermore, we demonstrated that the members of miR-17-92 cluster were decreased in the sera of EV71 infected patients, suggesting the clinical implication and the potential therapeutic application of miR-17-92.

Highlights

Enterovirus 71 (EV71), a small, non-enveloped, icosahedral RNA virus that belongs to the family Picornaviridae and an etiological agent for hand-foot and-mouth disease (HFMD), has caused several outbreaks worldwide and sometimes resulted in severe neurological disorders and mortality in children (McMinn, 2002; Solomon et al, 2010; Chang et al, 2016)
To investigate the impact of EV71 infection on the cellular miRNAs, we performed small RNA deep sequencing analysis on host cellular miRNAs in HT-29 cells infected with EV71 at a MOI of 1 for 24 h
On the basis of differentially expressed miRNAs, we identified 101 miRNAs that were modulated by EV71 infection (Supplementary Figures S1A,B)

Summary

Introduction

Enterovirus 71 (EV71), a small, non-enveloped, icosahedral RNA virus that belongs to the family Picornaviridae and an etiological agent for hand-foot and-mouth disease (HFMD), has caused several outbreaks worldwide and sometimes resulted in severe neurological disorders and mortality in children (McMinn, 2002; Solomon et al, 2010; Chang et al, 2016). Virus infections can alter host gene expression, including miRNAs, contributing to viral propagation and pathogenesis (Skalsky and Cullen, 2010). MicroRNAs (miRNAs) are abundant small non-coding RNAs (ncRNAs), ∼19–24 nucleotide nucleotides (nts) in length, and play crucial roles in regulating both cellular and viral gene expression (Gottwein and Cullen, 2008; Lee and Dutta, 2009). Our previous study showed that EV71 repressed the has-miR-30a expression to induce autophagic activity and benefit its replication (Fu et al, 2015). Those findings suggested that cellular miRNA-virus interaction may serve as a novel regulatory mechanism for antiviral therapy

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Conclusion