LncRNA TUG1 regulates the balance of HuR and miR-29b-3p and inhibits intestinal epithelial cell apoptosis in a mouse model of ulcerative colitis.

This study aimed to investigate the role of long non-coding RNA (lncRNA) taurine up-regulated 1 (TUG1) in the development of ulcerative colitis (UC) and to explore the underlying mechanisms. A murine model of UC was induced by dextran sodium sulfate (DSS) exposure. The colonic epithelial YAMC cells were treated with TNF-α to simulate the inflammatory environment of intestinal epithelial cells (IECs). RNA pull-down and RIP assays were performed to analyze the interaction between TUG1 and HuR. Luciferase activity assay was conducted to evaluate the interaction between TUG1 and miR-29b-3p. Cell proliferation was evaluated by MTT assay. Cell apoptosis was assessed by flow cytometry and western blot analysis of apoptosis-related proteins. TUG1 overexpression promoted cell proliferation and inhibited cell apoptosis in the TNF-α-stimulated YAMC cells. The mechanistic analysis showed that TUG1 positively regulated the HuR/c-myc axis via its interaction with HuR, leading to upregulation of c-myc expression; meanwhile, TUG1 negatively regulated the miR-29b-3p/CDK2 signaling via binding to miR-29b-3p, leading to derepression of CDK2 expression. Further animal experiments showed that TUG1 overexpression attenuated UC progression in the DSS-induced UC in mice. Collectively, TUG1 inhibits IEC apoptosis and UC progression by regulating the balance of HuR and miR-29b-3p.