MicroRNA expression profiling in fowl adenovirus serotype 4-infected Leghorn male hepatoma cells using small RNA deep...

Fowl adenovirus serotype 4 (FAdV-4) is the causative agent of hydropericardium-hepatitis syndrome (HHS), a disease that causes severe economic losses to the global poultry industry. MicroRNAs (miRNAs) are key regulators of host-pathogen interactions; yet, their temporal expression dynamics and functional roles during FAdV-4 replication in chicken-derived cells remain poorly defined. This study characterized the temporal expression profile of host miRNAs during FAdV-4 infection in Leghorn male hepatoma (LMH) cells to elucidate their regulatory roles in viral replication through small RNA deep sequencing and functional validation. We identified 63 and 126 differentially expressed (DE) miRNAs at 12 hpi and 24 hpi, respectively. These DE miRNAs exhibited time-dependent regulatory functions throughout FAdV-4 infection, and KEGG enrichment confirmed persistent enrichment of their potential target genes within the MAPK signaling and metabolic pathways at both 12 hpi and 24 hpi. Moreover, we also revealed that gga-miR-184-5p could inhibit FAdV-4 replication, while gga-miR-7447-3p could promote FAdV-4 replication. Dual-luciferase reporter assays demonstrated that Family with Sequence Similarity 135 Member B (FAM135B) is directly targeted by gga-miR-184-5p. Overexpression of FAM135B suppressed FAdV-4 replication, an effect that was partially reversed by the introduction of gga-miR-184-5p. These findings deepen our understanding of host-FAdV-4 interaction mechanisms and provide valuable candidate targets for future development of antiviral strategies against FAdV-4 infection in poultry.