Peripheral blood miR-372 as a biomarker for ulcerative colitis via direct targeting of NLRP12

The present study aimed to investigate the expression pattern and underlying mechanism of microRNA-372 (miR-372) in the progression of ulcerative colitis (UC). Reverse transcription-quantitative polymerase chain reaction was used to measure miR-372 expression levels in the blood and colonic mucosa tissue samples from patients with UC. The present study demonstrated that levels of miR-372 were significantly increased in the blood and colonic mucosa tissue samples from patients with UC compared with healthy controls. Furthermore, the level of serum miR-372 was positively correlated with the level of serum c-reactive protein. Receiver operating characteristic analysis indicated that levels of miR-372 detected in serum and tissue samples could be used to screen for patients with UC from healthy controls. These results indicated a potential role of miR-372 as a diagnostic marker and therapeutic target for patients with UC. Furthermore, a conserved miR-372 binding site in the 3'untranslated region of the NLR family pyrin domain containing 12 (NLRP12) was identified. Dual luciferase assay demonstrated that overexpression of miR-372 significantly reduced the relative luciferase activity of pmirGLO-NLRP12-3'UTR compared with control pmirGLO. In addition, western blot analysis indicated that overexpression of miR-372 significantly decreased the protein expression level of NLRP12. Therefore it was hypothesized that miR-372 may promote the progression of UC by suppressing NLRP12 protein expression and thereby inducing the excessive production of inflammatory cytokines. In conclusion, high levels of miR-372 detected in peripheral blood samples may serve a role as a potential biomarker to screen potential patients with UC from healthy controls.