CircNFIC Balances Inflammation and Apoptosis by Sponging miR-30e-3p and Regulating DENND1B Expression

Abstract

Disordered inflammation and apoptosis are closely related to diseases, and inflammation can also promote cell apoptosis, where growing evidence has shown that circular RNAs (circRNAs) play important roles. Lipopolysaccharide (LPS) is the main component of the cytoderm of gram-negative bacterium, which can cause inflammatory responses in macrophages. We constructed an inflammatory model by exposing chicken macrophage cell lines (also known as HD11) to LPS for in vitro experiments. In this study, we validated a novel circRNA—circNFIC—which was dramatically up-regulated in tissues infected by coccidia and cells exposed to LPS. Besides, circNFIC could significantly promote the expression levels of pro-inflammation factors, including (IL-1β, TNFα, and IFNγ) and pro-apoptosis maker genes (caspase 3 and caspase 8) in HD11 exposed to LPS or not. In terms of mechanism, circNFIC exerted notable effects on DENND1B to regulate cell inflammation and apoptosis by sponging miR-30e-3p. The molecular functions played by miR-30e-3p and DENND1B have been explored, respectively. In addition, the effects of circNFIC knockdown suppressing the expression of pro-inflammatory and pro-apoptosis functions could be reversed by a miR-30e-3p inhibitor. On the whole, circNFIC promoted cell inflammation and apoptosis via the miR-30e-3p/DENND1B axis.