Effects of Salmonella Pullorum Infection on miRNA Expression Profiles in Spleen of Chicks

PurposeTo identify the differentially expressed miRNA in spleen of chicken infected with Salmonella Pullorum, providing a theoretical basis for clarifying the regulatory mechanism of miRNA in Salmonella Pullorum infection.

MethodsSpleens from SPF chicks infected and uninfected with Salmonella Pullorum were collected, spleen RNA was extracted, and six miRNA libraries were constructed. The differentially expressed miRNA were screened by Illumina Hiseq 2500 high-throughput sequencing technology and bioinformatics technology, the target genes were predicted by TargetScan and miRanda, and the predicted target genes were analyzed using GO functional enrichment and KEGG pathway enrichment. Finally, RT-qPCR was used to verify the sequencing results.

ResultsA total of 29 differentially expressed miRNAs were obtained, including 15 significantly up-regulated and 14 significantly down-regulated miRNAs. Immune-related biological processes such as positive regulation of lipopolysaccharide-mediated signaling pathways and negative regulation of NIK/NF-κB-mediated signaling pathways were significantly enriched in GO analysis. KEGG pathway enrichment showed that differentially expressed miRNA were mainly involved in immune-related pathways such as lysosome and endocytosis. In addition, the results of high-throughput sequencing were consistent with those of RT-qPCR.

ConclusionThe miRNA expression profile of chicks spleen infected with Salmonella Pullorum is successfully identified, and 29 potential miRNAs related to Salmonella Pullorum infection are obtained.