不同分期溃疡性结肠炎结肠黏膜血清素再摄取转运体的表达分析

Objective: To detect the expression of serotonin reuptake transporter (SERT) in mucosa of patients with ulcerative colitis (UC) of different stages and investigate the pathogenesis of irritable bowel syndrome (IBS) in UC patients. Methods: We enrolled 31 UC patients (17 males and 14 females) from 2011 to 2015. Their average age was (47.2±5.3) years old. There were 11 patients at active stage and 20 patients at remission stage. We collected the history data and used the results of conventional colonoscopy which determined the stages of UC. Colonic mucosa in remission could be divided into regular and irregular vascular patterns by narrow band imaging. Matts' degree was evaluated by HE staining. The expressions of SERT, TPH-1 and inflammatory factor were detected by Real-time PCR and IHH. Expressions of inflammation- and angiogenesis-related genes in colonic mucosa with unregular pattern and regular vessel pattern were detected by using high-throughput PCR analysis system. The expressions of SERT and inflammatory genes in colonic mucosa were detected dynamically at different time points in mouse model of colitis by DSS. All data were treated with SPSS 21.0. Results: The relative concentration of SERT gene and tissue expression in intestinal epithelial cells (active mucosa) were significantly lower than that of inactive mucosa (P<0.001). The expression of SERT was negatively correlated with the IBS-like symptoms. The relative concentration of IL-8 mRNA in intestinal epithelial cells (active mucosa) was significantly higher than that of inactive mucosa (P<0.001). The relative concentration of SERT mRNA was negatively related to the relative concentration of IL-8 mRNA and the Matts score (r=-0.38, P<0.001, r=-0.59, P=0.002). The expressions of TPH-1 mRNA and IL-8 mRNA were not significantly correlated (r=0.28, P=0.100). The Matts score and TPH-1 mRNA were lower in regular vascular type mucosa than in irregular vascular type, while SERT expression of regular vascular type mucosa was higher. The relative expressions of IL-1, IL-8, CXCL3, CXCL5 and CXCL1 were significantly increased in irregular type mucosa. SERT expression in DSS mice was lower than those in control group (P=0.001). Conclusion: SERT expression is down-regulated both in colonic mucosa in active-stage UC patients and in mucosa of irregular vascular pattern. SERT is involved in the pathogenesis of IBS-like symptoms in UC related to inflammation and pre-vascular mechanism.