LncRNA NEAT1 mediates intestinal inflammation by regulating TNFRSF1B

Inflammatory bowel disease (IBD) is a chronic nonspecific intestinal disease. Our previous work showed that long non-coding RNA (LncRNA) nuclear enriched abundant transcript 1 (NEAT1) plays an important role in IBD. In the current study, we aimed to explore the underlying mechanism by which NEAT1 participates in the development of the disease.

Real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression of NEAT1 and tumor necrosis factor superfamily member 1B (TNFRSF1B) in clinical specimens and dextran sulfate sodium (DSS) colitis mice. Inflammatory cell models were established by stimulating human normal intestinal epithelial cell line NCM460 and human colon cancer cell line HT-29 with tumor necrosis factor alpha (TNF-α). Expressions of inflammatory cytokines such as interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) were detected by enzyme-linked immunosorbent assay (ELISA) or RT-qPCR, TNFRSF1B, NF-κB p65 and p-NF-κB p65 followed by the knockdown or overexpression of NEAT1 and TNFRSF1B were analyzed by western blotting, and the regulatory effects of NEAT1 on TNFRSF1B were detected by RNA pull-down experiments and RNA-decay assay. The translocation of NF-κB p65 to the nucleus was detected by immunofluorescence.

In patients' specimens and DSS colitis mouse models, NEAT1 and TNFRSF1B expression were up-regulated compared with the control group. TNF-α stimulation increased NEAT1 and TNFRSF1B expression and activated NF-κB signaling pathway by increasing the translocation of NF-κB p65 to the nucleus. In the presence of TNF-α stimulation, NEAT1 knockdown reduces the expression of TNFRSF1B and the translocation of NF-κB p65, thereby relieves cell inflammation. These effects can be reversed by the overexpression of TNFRSF1B.In addition, NEAT1 is involved in inflammatory response by up-regulating the mRNA levels of TNFRSF1B, and knocking down NEAT1 can alleviate inflammation by down-regulating TNFRSF1B. Moreover, NEAT1 co-precipitates TNFRSF1B mRNA in RNA-pulldown assay, and the presence of NEAT1 stabilizes the mRNA of TNFRSF1B.

Our results showed that LncRNA NEAT1 promotes NF-κB p65 translocation and mediates intestinal inflammation by regulating TNFRSF1B.