Correlation of Intestinal Mucosal Healing and Tight Junction Protein Expression in Ulcerative Colitis Patients

The aim of this study was to investigate the relationship between intestinal mucosal healing and tight junction (TJ) protein expression in patients with ulcerative colitis (UC).A total of 40 patients with UC were included as an experimental group and UC disease activity was evaluated using the Mayo clinic score (MCS) and 8 patients with normal distal colon served as the control group. The expression of TJ proteins including occludin, ZO-1 and claudin-2 were determined by immunohistochemistry and their correlation with clinical characteristics were also analyzed.Statistically significant differences regarding the MCS and Mayo endoscopic subscore (MES) were observed in both groups (P < 0.01). The Geboes index was significantly increased in patients with active UC compared to patients with quiescent UC and normal controls (P < 0.01). Patients with active and quiescent UC had upregulated expression of claudin-2 and reduced expression of occludin and ZO-1 compared to those of normal controls. The expression of ZO-1 was significantly higher in patients with quiescent UC with mucosa healing (P < 0.05) compared with those without mucosal healing. The expression of ZO-1 and occludin was negatively correlated with MCS, MES, Geboes, C-reaction protein and erythrocyte sedimentation rate. The expression of claudin-2 was positively correlated with MCS, MES, Geboes, C-reaction protein and erythrocyte sedimentation rate.These findings suggest that TJ proteins play a crucial role in mucosal healing, and may be a potential marker of response when evaluating therapeutic interventions.