Brief Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Nov 21, 2011; 17(43): 4810-4816
Published online Nov 21, 2011. doi: 10.3748/wjg.v17.i43.4810
Schistosoma japonicum ova maintains epithelial barrier function during experimental colitis
Chen-Mei Xia, Yuan Zhao, Li Jiang, Jie Jiang, Shun-Cai Zhang
Chen-Mei Xia, Yuan Zhao, Li Jiang, Jie Jiang, Shun-Cai Zhang, Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
Author contributions: Xia CM and Zhao Y performed majority of the experiments and contributes equality to this work; Jiang L and Jiang J were responsible for the pathology and bacterial translocation parts; Zhang SC designed the study and provided financial support.
Correspondence to: Shun-Cai Zhang, Professor, MD, PHD, Department of Gastroenterology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China. doctorzhangsc@163.com
Telephone: +86-21-64041990-2424 Fax: +86-21-64035399
Received: May 1, 2011
Revised: June 24, 2011
Accepted: July 1, 2011
Published online: November 21, 2011
Abstract

AIM: To evaluate the impacts of Schistosoma japonicum (S. japonicum) ova on the tight junction barriers in a trinitrobenzenesulfonic acid (TNBS)-induced colitis model.

METHODS: Balb/c mice were randomly divided into three groups: control group; TNBS+ova- group and TNBS+ova+ group. TNBS was used intracolonic to induce colitis and mice of the TNBS+ova+ group were pre-exposed to S. japonicum ova as a prophylactic intervention. Colon inflammation was quantified using following variables: mouse mortality, weight loss, colon extent and microscopic inflammation score. Serum expression of tumor necrosis factor-α and interferon-γ were assessed to evaluate the systemic inflammatory response. NOD2 and its mRNA were also tested. Bacterial translocations were tested by culturing blood and several tissues. ZO-1 and occludin were chosen as the representations of tight junction proteins. Both the proteins and mRNA were assessed.

RESULTS: Ova pre-treatment contributed to the relief of colitis and decreased the mortality of the models. NOD2 expression was significantly downregulated when pretreated with the ova. The TNBS injection caused a significant downregulation of ZO-1 and occludin mRNA together with their proteins in the colon; ova pre-exposure reversed these alterations. Treatment with S. japonicum ova in the colitis model caused lower intestinal bacterial translocation frequency.

CONCLUSION: S. japonicum ova can maintain epithelial barrier function through increasing tight junction proteins, thus causing less exposure of NOD2 to the luminal antigens which may activate a series of inflammatory factors and induce colitis.

Keywords: Crohn’s disease, Schistosoma japonicum ova, Tight junction protein, ZO-1, Occludin