miR-148 targets CiGadd45ba and CiGadd45bb to modulate the inflammatory response to bacterial infection in grass carp.

In grass carp (Ctenopharyngodon idella), septicemia is a systemic inflammatory response to bacterial infection. Once infected bacteria, a hyper-inflammatory state that could lead to septic shock and death. There is increasing evidence that microRNAs are involved in the regulation of the inflammatory response. Ctenopharyngodon idella growth arrest and DNA damage-inducible 45 ba and bb (CiGadd45ba and CiGadd45bb) are two subtypes of Gadd45b. In the present study, miR-148 was confirmed to be involved in the inflammatory response after infection with Aeromonas hydrophila. Dual-luciferase reporter assays and miRNA expression profiling confirmed that miR-148 targeted both CiGadd45ba and CiGadd45bb. Transfection with miR148 mimics and inhibitors altered the expression levels of proinflammatory genes, suggesting that miRNAs regulate the immune response in grass carp. Our results provide a theoretical basis for studying the molecular mechanism underlying the regulation of inflammation by miR-148 in grass carp.