CIRC_0085323 SILENCING INHIBITS TNF-Α-INDUCED NORMAL HUMAN COLONIC EPITHELIAL CELL INFLAMMATION AND APOPTOSIS THROUGH THE MIR-495-3P/TRAF3 AXIS

Abstract

ABSTRACT Background: Previous data have suggested the involvement of circular RNA (circRNA) in ulcerative colitis (UC) development. However, the role and mechanism of circ_0085323 in UC occurrence have not been reported. Methods: Normal human colonic epithelial cells (NCM460) were treated with TNF-α to simulate UC-like cell inflammation and injury in vitro. The expression of circ_0085323, microRNA-495-3p (miR-495-3p), and TNF receptor–associated factor 3 (TRAF3) was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blotting analysis. Cell viability, cell proliferation, and cell apoptosis were investigated by cell counting kit-8 assay, 5-ethynyl-29-deoxyuridine assay, and flow cytometry analysis, respectively. IL-1β, IL-6, and IL-8 production were analyzed by enzyme-linked immunosorbent assays. Lactate dehydrogenase activity was assessed by a lactate dehydrogenase activity detection assay. The interactions among circ_0085323, miR-495-3p, and TRAF3 were identified by dual-luciferase reporter assay and RNA immunoprecipitation assay. Results: Circ_0085323 was overexpressed in the colonic mucosal tissues of UC patients and TNF-α–stimulated NCM460 cells. Circ_0085323 knockdown relieved TNF-α–induced inhibitory effect on the proliferation of NCM460 cells and promoting effects on cell apoptosis and inflammation. Circ_0085323 acted as a miR-495-3p sponge, and the effects of circ_0085323 silencing on TNF-α–induced NCM460 cell injury were attenuated by decreasing miR-495-3p expression. TRAF3 was targeted by miR-495-3p, and circ_0085323 combined with miR-495-3p to regulate TRAF3. TRAF3 depletion not only alleviated TNF-α–induced NCM460 cell damage but also partially revoked the effect of circ_0085323 silencing combined with miR-495-3p depletion on TNF-α–induced NCM460 cell injury. Conclusions: Circ_0085323 knockdown ameliorated TNF-α–induced NCM460 cell injury by regulating the miR-495-3p/TRAF3 axis, which suggested that circ_0085323 might be a therapeutic target for UC.