Screening, verification, and diagnostic value of differentially expressed miRNAs in serum of sheep infected with Echinococcus granulosus

Objective To identify the value of differentially expressed miRNAs in the diagnosis of Echinococcosis granulosis, the expression profiles of serum miRNAs between Echinococcus granulosus-infected and un-infected sheep were analyzed and the value of differentially expressed miRNAs in diagnosis of Echinococcosis was validated by the real-time fluorescence quantitative PCR (qRT-PCR) technology. Methods Total RNAs were extracted from the sheep sera of Echinococcus granulosus-infected group and uninfected group, and the differentially expressed miRNAs were identified and screened by high-throughput sequencing, and miRNAs with significant differential expressions were selected to be validated by qRT-PCR. The target genes of differentially expressed miRNAs were predicted, and Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed. Results Twenty-six differentially expressed miRNAs were screened out from the serum of the Echinococcus granulosus infected group and the healthy control group, of which 21 miRNAs were up-regulated and 5 miRNAs were down-regulated. The target genes of some differentially expressed miRNAs may be involved in the regulation of genes related to inflammatory response, autophagy, and apoptosis. The relative expression levels of oar-miR-191 and oar-miR-150 in the serum of the Echinococcus granulosus infected group showed an upward trend compared with the control group and the difference was statistically significant (P < 0.05). The ROC curve analysis showed serum oar-miR-191 yielded an AUC of 0.858 (95CI: 0.719-0.997, P < 0.008), with 71.43% sensitivity and 85.71% specificity. The serum oar-miR-150 yielded an AUC of 0.738 (95CI: 0.550-0.926, P<0.026), with 53.33% sensitivity and 86.67% specificity. Conclusion The existence of numerous differentially expressed miRNAs in the serum from Echinococcus granulosus-infected sheep has revealed by high-throughput sequencing. Through the qRT-PCR detection and ROC curve analysis, it was found that oar-miR-191 showed good sensitivity and specificity in the diagnosis of Echinococcus granulosus infection, which has the potential to be a biomarker for Echinococcosis.