MicroRNA-34a-5p plays a role in regulating chicken enteritis and intestinal barrier

Chicken enteritis severely reduces poultry productivity by impairing nutrient absorption and growth. Given the critical regulatory roles of small RNAs – particularly miR-34a-5p – in intestinal inflammation, this study investigated its specific function and underlying mechanisms in the pathogenesis of chicken intestinal inflammation. This study showed that dextran sodium sulphate (DSS)-induced enteritis in chickens led to reduced body weight, impaired intestinal structure, decreased hepatic antioxidant capacity, upregulated intestinal pro-inflammatory factor mRNA, and downregulated barrier protein mRNA. qRT-PCR analysis showed that gga-miR-34a-5p expression was significantly upregulated in the rectum of chickens with enteritis compared with controls. Target gene prediction and bioinformatics analysis revealed that the mature sequence of miR-34a-5p was highly conserved across species, and transcription factor binding sites (including NFYA, ZEB1, and NFAT5) were identified in its promoter region. Using the TargetScan and miRDB data platforms to predict target genes of miR-34a-5p, 107 target genes were identified, including NOTCH1, DLL1, PPP3R1, BCL2, SATB2, and FOXP2. We identified NOTCH1 and SATB2 as hubs for the critical pathways through protein–protein interaction (PPI) network analysis. qRT-PCR confirmed the expression levels of the predicted target genes in the control and model groups. The predicted target genes of gga-miR-34a-5p, including NOTCH1, DLL1, PPP3R1, BCL2, SATB2 and FOXP2, are involved in regulating multiple signalling pathways such as the NOTCH, WNT, and P53 pathways. In the DSS-induced intestinal inflammation model, gga-miR-34a-5p regulates the initiation and progression of intestinal inflammation and mucosal impairment by targeting both the NOTCH1 signalling pathway (via its ligand DLL1) and SATB2/FOXP2.