Down-regulated gga-miR-223 inhibits proliferation and induces apoptosis of MG-infected DF-1 cells by targeting FOXO3

Mycoplasma gallisepticum (MG) is a major poultry pathogen that can induce Chronic Respiratory Disease (CRD) in chickens, causing serious economic losses the industry worldwide. Increasing evidence suggests microRNAs (miRNAs) act as vital role resisting microbial pathogenesis and maintaining cellular mechanism. Our previous miRNAs sequencing data showed gga-miR-223 expression level significantly decreased MG-infected chicken lungs. The aim of this study was to reveal MG-induced CRD progression. We found remarkably down regulated forkhead box O3 (FOXO3) up-regulated both embryos lungs embryonic fibroblast cell line (DF-1) by qPCR. FOXO3 verified target gene through bioinformatics analysis dual-luciferase reporter assay. Further studies overexpressed could promote proliferation, cycle, inhibit apoptosis notably promoting cycle marker genes cyclin-dependent kinase 1 (CDK1), 6 (CDK6) Cyclin D1 (CCND1) inhibiting markers Bcl-2-like 11(BIM), FAS ligand (FASLG) TNF-related apoptosis-inducing (TRAIL). As expected, knockdown group got similar results. Overexpression observably promoted multiplication, progression, inhibited DF-1 cells, while had opposite effect. Taken together, upon MG-infection, downregulated decrease increase directly targeting exert an aggravating MG-infectious