Novel MicroRNA Involved in Host Response to Avian Pathogenic Escherichia coli Identified by Deep Sequencing and Integration Analysis

Avian pathogenic Escherichia coli (APEC) causes one of the most common bacterial diseases of poultry worldwide. Effective control methods are, therefore, desirable and will be facilitated by a better understanding of the host response to the pathogen. Currently, miRNAs involved in host resistance to APEC are unknown. Here, we applied RNA sequencing to explore the changed miRNAs and deregulated genes in the spleen of broilers from non-challenged (NC), APEC challenged-mild pathology (CM), and APEC challenged-severe pathology (CS) groups. Twenty-seven differentially expressed miRNAs (fold change > 1.5, p-value In vitro, gga-miR-429 directly repressed luciferase reporter gene activity via binding to 3’ -untranslated regions of TMEFF2, NTRK2 and SHISA2. Over-expression of gga-miR-429 in the HD11 macrophage cell line significantly inhibited TMEFF2 and SHISA2 expression, which are involved in the lipopolysaccharide-induced PDGF and Wnt signaling pathways. In summary, we provide the first report characterizing the miRNA changes during APEC infection, which may help to shed light on the roles of these recently identified genetic elements in the mechanisms of host resistance and susceptibility to APEC.