Analysis of miRNAs Involved in Mouse Brain Damage upon Enterovirus 71 Infection

Enterovirus 71 (EV71) infects the central nervous system (CNS) and causes brainstem encephalitis in children. MiRNAs have been found to play various functions in EV71 infection in human cell lines. To identify potential miRNAs involved in the inflammatory injury in CNS, our study, for the first time, performed a miRNA microarray assay in vivo using EV71 infected mice brains. Twenty differentially expressed miRNAs were identified (four up- and sixteen down-regulated) and confirmed by qRT-PCR. The target genes of these miRNAs were analyzed using KEGG (Kyoto Encyclopaedia of Genes and Genomes) analysis, revealing that the miRNAs were mainly involved in the regulation of inflammation and neural system function. MiR-150-5p, -3082-5p, -3473a, -468-3p, -669n, -721, -709, and -5107-5p that regulate MAPK and chemokine signaling were all down-regulated, which might result in increased cytokine production. In addition, miR-3473a could also regulate focal adhesion and leukocyte trans-endothelial migration, suggesting a role in virus-induced blood-brain barrier disruption. The miRNAs and pathways identified in this study could help to understand the intricate interactions between EV71 and the brain injury, offering new insight for the future research of the molecular mechanism of EV71 induced brainstem encephalitis.