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

BACKGROUND: 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).

MATERIALS AND METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.