Roles Of TCF-4and NOD2in The Pathogenesis Of Ulcerative Colitis Induced By DSS In Balb/c Mice

Abstract:To study the roles of TCF-4and NOD2in the pathogenesis of ulcerative colitis (UC), the healthy Balb/c mice were used as the object of study in this experiment.7%DSS solution were drunk by the experimental mice freely, and the model of acute UC would be built after7days. The duodenum, jejunum, ileum and colon of the mice will be take and store after treatment1d,3d,5d and7d respectively, and then the TCF-4mRNA and NOD2mRNA will be detected by RT-PCR, the protein of TCF-4will be detected by immunohistochemistry. According to the dynamic expression pattern of TCF-4and NOD2, the roles of them in the pathogenesis of UC will be investigated in this study. The main results are as follows:1. After drinking7%DSS solution7days, the body weight of mice declined dramatically, while the DAI score increased gradually. Compared with the control mice, significant changes of acute UC have been observed in the colon of the experimental mice, explained that the acute UC model has been replicated successfully.2. The results of RT-PCR showed that the expression levels of TCF-4mRNA presented dynamic change in the different periods of acute UC model, and also had significant differences. The conditions of small intestinal tissues are as follow:the expression level of TCF-4mRNA in the duodenum reached highest at5d, and at this time with the significant difference (P<0.01) compared to that of Od in the duodenum; the expression level of TCF-4mRNA in the jejunum reached highest at1d, with the significant difference (P<0.01) compared to that of0d、3d、5d、7d in the jejunum; the expression level of TCF-4mRNA in the ileum reached highest at5d, with the significant difference (P<0.01) compared to that of0d、1d、3d in the ileum, with the significant difference (P<0.05) compared to that of7d; the expression level of TCF-4mRNA in the colon reached highest at7d, with the no significant difference (P>0.05) compared to that of0d in the colon. with the significant difference (P<0.01) compared to that of1d in the colon.3. The results of RT-PCR showed that the expression levels of NOD2mRNA presented dynamic change in the different periods of acute UC model, and also had significant differences. The conditions of small intestinal tissues are as follow:the expression level of NOD2mRNA in the duodenum reached highest at1d, and at this time with no significant difference (P>0.05) compared to that of0d、3d、5d、7d in the duodenum; the expression level of NOD2mRNA in the jejunum reached highest at7d, with the significant difference (P<0.01) compared to that of Od in the jejunum; and with the significant difference (P<0.05) compared to that of1d、3d、5d in the jejunum; the expression level of NOD2mRNA in the ileum reached highest at Id, with no significant difference (P>0.05) compared to that of0d、3d、5d、7d in the ileum, the expression level of NOD2mRNA in the colon reached highest at5d, with the significant difference (P<0.01) compared to that of1d in the colon.4. The results of immnohistochemistry showed that most of the TCF-4protein expressed in the shedding of epithelium cells, inflammatory cells in the enteric cavity of colon, connective tissue hyperplasia, inflammatory cells infiltrating into the submucosa and intestinal crypt hyperplasia; in addition, the TCF-4protein also can be found in the Paneth cells of small intestinal, and presented dynamic change in all the intestinal tissues in the different periods of acute UC model with significant differences, of which the expression of TCF-4protein in the duodenum reached highest at5d, with the significant difference (P<0.01) compared to that of0d、1d, which is the lowest one, with the significant difference (P<0.01) compared to that of3d,5d, and7d; the expression of TCF-4protein in the jejunum reached highest at1d, with significant difference (P<0.01) compared to that of0d, and with significant difference(P<0.05) compared to that of3d; the expression of TCF-4protein in the ileum reached highest at5d, with the significant difference (P<0.01) compared to that of Od and3d, and with the significant difference (P<0.05) compared to that of1d; the expression of TCF-4protein in the colon reached highest at7d,with the significant difference (P<0.01) compared to that of1d.All of these results indicated that, the acute UC model has been replicated successfully in this experiment. It is also found that the TCF-4has been detected in the normal and UC intestinal tissues of mice, especially in the Paneth cells of small intestinal and colon tissues. The expression level of TCF-4presented dynamic change and had significant differences, which showed that TCF-4have close relationship with the Paneth cells and the development of UC disease, and also play an important role in the pathogenesis of UC, providing a theoretical basis for the further illumination of the nosogenesis of UC, also providing a experimental basis for the clinical treatment of UC.