Differential expression and bioinformatics analysis of microRNAs in exosomes of sheep poxvirus-infected cells

Sheep pox is widespread worldwide and is the most severe animal pox virus infection. This study aimed to identify the key microRNAs (miRNAs) differentially expressed in the exosomes of sheep poxvirus-infected cells and their target genes and related pathways and provide a theoretical basis for an in-depth understanding of the molecular mechanisms of sheep poxvirus-infected cells. In this study, the differentially expressed miRNAs were verified by quantitative polymerase chain reaction (qPCR), and the target genes of miRNAs were predicted and analyzed by bioinformatics. The qPCR results showed that the expression trends of oar-miR-21, oar-miR10b, oar-let-7f, oar-let-7b, and oar-miR-221 were consistent with the sequencing results. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes results showed that differentially expressed miRNAs were mainly involved in the immune system processes of the Arf6 downstream pathway. The target genes Reactome pathways were mainly enriched in the RAC1 GTPase cycle, CDC42 GTPase cycle, RHO GTPase cycle, RHOV GTPase cycle, and post-transcriptional silencing of small RNAs. The transcription factors SP4, NKX6-1, MEF2A, SP1, EGR1, and POU2F1 that may be connected to sheep pox virus (SPPV)-infected cells were discovered by transcription factor annotation screening. In conclusion, this study screened for differentially expressed miRNAs in SPPV-infected cells and performed a series of bioinformatic analyses of their target genes to provide a theoretical basis for the molecular mechanism of SPPV infections of cells. The data can be used as basic information in future studies on the defense mechanisms against poxvirus infections.