Transcriptional Regulation of RIP2 Gene by NFIB Is Associated with Cellular Immune and Inflammatory Response to APEC Infection

Abstract

Avian pathogenic E. coli (APEC) can cause localized or systemic infection, resulting in large economic losses per year, and impact health of humans. Previous studies showed that RIP2 (receptor interacting serine/threonine kinase 2) and its signaling pathway played an important role in immune response against APEC infection. In this study, chicken HD11 cells were used as an in vitro model to investigate the function of chicken RIP2 and the transcription factor binding to the RIP2 core promoter region via gene overexpression, RNA interference, RT-qPCR, Western blotting, dual luciferase reporter assay, CHIP-PCR, CCK-8, and flow cytometry assay following APEC stimulation. Results showed that APEC stimulation promoted RIP2 expression and cells apoptosis, and inhibited cells viability. Knockdown of RIP2 significantly improved cell viability and suppressed the apoptosis of APEC-stimulated cells. Transcription factor NFIB (Nuclear factor I B) and GATA1 (globin transcription factor 1) binding site was identified in the core promoter region of RIP2 from −2300 bp to −1839 bp. However, only NFIB was confirmed to be bound to the core promoter of RIP2. Overexpression of NFIB exacerbated cell injuries with significant reduction in cell viability and increased cell apoptosis and inflammatory cytokines levels, whereas opposite results were observed in NFIB inhibition treatment group. Moreover, RIP2 was up-regulated by NFIB overexpression, and RIP2 silence mitigated the effect of NFIB overexpression in cell apoptosis, inflammation, and activation of NFκB signaling pathways. This study demonstrated that NFIB overexpression accelerated APEC-induced apoptosis and inflammation via up-regulation of RIP2 mediated downstream pathways in chicken HD11 cells.

Editorial of Special Issue “Roles of Inflammasomes and Methyltransferases in Inflammation”

“…The research article by Sun et al investigated the functional regulation of RIP2 (receptor-interacting serine/threonine kinase 2) mediated by transcription factors binding to a RIP2 promoter region in the immune response against avian pathogenic E. coli (APEC) infection. A previous study showed that the RIP2-mediated signaling pathway played a pivotal role in the immune response against APEC infection, and this study further demonstrated that the transcriptional regulation of RIP2 by transcription factor NFIB plays a key role in cellular immune and inflammatory response against APEC infection [ 13 ].…”

Genetic resilience in chickens against bacterial, viral and protozoal pathogens

“…E. coli infection promotes RIP2 expression and inhibits cell viability, whereas knockdown of RIP2 restores cell viability and represses the apoptosis of chicken HD11 cells. Nuclear factor I B increases the expression of RIP2, reduces cell viability, and accelerates E. coli-induced apoptosis, confirming that RIP2 supported E. coli proliferation in chicken cells (70). Mycoplasma gallisepticum infects the lungs of chickens and causes chronic respiratory disease.…”

Transcriptional regulation of NDUFA4L2 by NFIB induces sorafenib resistance by decreasing reactive oxygen species in hepatocellular carcinoma

“…Nuclear factor I B can directly or indirectly regulate gene transcription. Studies have shown that NFIB can directly promote the transcription of EZH2, 45 PINK1 6 , RIP2, 46 and ERO1A 47 or inhibit the transcription of p21, 12 CDK6, and CDK4 48 . However, it can also regulate gene expression by regulating chromatin accessibility 49 .…”