The Research On Relationship Between Intestinal Barrier And STAT3Signal Transduction Pathways In Ulcerative Colitis

ObjectiveUlcerative colitis is a chronic intestinal inflammatory disease with unknown etiology, mainly restricted to colorectal mucosa and submucosa. In recent years, the incidence of ulcerative colitis is increasing both in China and foreign countries. This study focuses on the expression of Claudin-1and STAT3in intestinal mucosa of ulcerative colitis patients. Relationship between intestinal barrier and signal transduction pathway with the clinical grading and pathogenesis of UC was investigated, and relationship between the expression of Claudin-1and STAT3was also studied. The aim of the study was to investigate the mechanism of UC and provide experimental basis for clinical treatment.Methods102cases of UC were collected from January2008to June2010in Tianjin Medical University General Hospital and divided into three groups (mild, moderate, and severe) according to Truelove grading.20cases of normal colonic tissue were regarded as control. Expression of Claudin-1and STAT3were evaluated by immunohistochemistry.Results1. Expression of Claudin-1in colonic tissue of UC patients is significantly decreased compared to that in control group (P<0.05). The expression of Claudin-1correlates with Truelove grading (P<0.05). The expression of Claudin-1has no correlation with age, sex, and extent of disease (P>0.05).2. Expression of STAT3in colonic tissue of UC patients is significantly increased compared to that in control group (P<0.05). The expression of STAT3correlates with Truelove grading (P<0.05). The expression of STAT3has no correlation with age, sex, and extent of disease (P>0.05).3. The expression of Claudin-1correlates with STAT3.(P<0.05) As the disease progresses, the expression of Claudin-1decreases and STAT3increases.Conclusion: The expression of Claudin-1in intestinal epithelial in UC patients is decreased, indicating that the intestinal barrier may be destroyed. This may serve as a useful candidate for evaluation of disease severity, therapeutic efficacy, and prediction of disease prognosis. The expression level of STAT3in UC patients is increased, demonstrating that it may play an important role in the pathogenesis of UC and be regarded as a novel therapeutic target for UC.As ulcerative colitis disease exacerbates, Claudin-1expression gradually decreased and STAT3expression gradually increased. Expression of Claudin-1and STAT3had negative correlation. These results imply a potential association between activation of STAT3signal transduction pathway and intestinal barrier.