The PVT1/miR-216a-5p/TLR4 Signaling Axis Regulates the Inflammation and Intestinal Epithelial Barrier Function of Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic, relapsing disease, imposing a heavy disease burden and severely reducing the quality life of patients. This study verified the influence of the PVT1/miR-216a-5p/TLR4 signaling axis on UC. LPS-stimulated RAW264.7 cells were co-cultured with Caco-2 cells to establish an in vitro model. The C57BL/6 J mice induced by 3% DSS were used as an in vivo model. Cytotoxicity and barrier function were evaluated in Caco-2 cells. The PVT1, miR-216a-5p, and TLR4 levels were detected by RT-qPCR. ELISA was used to detect the level of pro-inflammatory factors in RAW264.7 supernatant and colon tissue, and the level of ZO-1 and occludin in Caco-2 cells and colon tissue. TEER was used to evaluate the integrity of the barrier function of Caco-2 cells. The targeting relationships between PVT1, miR-216a-5p, and TLR4 were verified by dual-luciferase reporter gene assay. The PVT1 and TLR4 levels were increased, but miR-216a-5p was decreased in the LPS-treated RAW264.7, co-cultured Caco-2, and colon tissue of DSS mice. The pro-inflammatory factor levels in RAW264.7 and colon tissue of DSS mice were increased, while in Caco-2, the cytotoxicity was aggravated, and the integrity of the barrier function was disrupted. The levels of ZO-1 and occludin were decreased in Caco-2 cells and tissue. If the PVT1 expression was inhibited, the results showed an opposite trend. In contrast, inhibition of miR‑216a‑5p reversed the protective effects induced by PVT1 knockdown. The PVT1/miR-216a-5p signaling axis affects the inflammation and intestinal epithelial cell barrier function in UC, which may be a possible therapeutic target for UC.