A meta-analysis of differentially expressed microRNA during mastitis disease in dairy cattle

Abstract

Abstract Background: Bovine mastitis is an important inflammation disease that affects the mammary gland and causing adverse effects on the quality and quantity of the produced milk, leads to a major economic lost in dairy industry. Streptococcus uberisis one of the bacteria commonly responsible for inducing mastitis in dairy cattle. Susceptibility to develop mastitis is a complex multifactorial phenotype and the improvement of the miRNAs and their target genes has not been comprehensively illustrated. Methods and Results:The purpose of this investigation was to perform a meta-analysis of the miRNAs expression profiling datasets to detect the key miRNAs, targets, and regulatory networks associated with mastitis. To this, publicly available miRNA datasets belong to three experiments on dairy cattle which challenged with S. uberiswere included in our meta-analyzed. The identified differentially expressed miRNAs were used in TargetScan to identify their target genes. The functional impacts of the meta-miRNAs were further analyzed using Gene ontology and Protein-Protein Interaction network analysis. Three meta-miRNAs, namely bta-miR-98, bta-miR-138 and bta-miR-193a-3p, were obtained to be associated with the progress of the immune system and cell differentiation of the mammary gland during the mastitis. A total of 2061 target genes were identified that which bta-miR-98, bta-miR-138 and bta-miR-193a-3p were regulated 1121, 268 and 672 target genes respectively. Gene ontology analysis results were represented 237 biological process, 41 molecular function, 54 cellular component roles and nine KEGG pathways in mastitis disease. A total of 319, 113 and 124 target genes for bta-miR-98, bta-miR-193a-3p and bta-miR-138, respectively were inputted to cytoscape. The resulted network analysis showed that bta-miR-98 and bta-miR-138 have nine, bta-miR-138 and bta-miR-193a-3p have six, and bta-miR-193a-3p and bta-miR-98 have four common target genes. Twenty-one common genes were revealed by combing 360 common meta-genes in our previous research and 2061 meta-miRNA target genes. The procedure reported in this research offers a comprehensive scheme for the identification of the key miRNAs and target genes in mastitis disease by using global transcriptome data, meta-analysis, gene ontology, enrichment analysis and protein protein interaction. Conclusion: The findings of the current work suggest miRNAs are crucial amplifiers of inflammatory response by controlling metabolic pathway and inhibitors of several biological processes during S. uberis infection.