动物造模 z-bio 2022-08-05 558

　　Objective To establish a mouse model of ulcerative colitis with dextran sodium sulfate (DSS) and 2,4,6-trinitrobenzenesulfonic acid (TNBS), and to compare the clinical symptoms, pathological damage of colon and colonic flora.

　　Methods Thirty C57BL/6 male mice were randomly divided into control group, DSS group and TNBS group. The modeling period was 7 d. Clinical symptoms, including body weight and fecal occult blood, were monitored daily. At the end of modeling, colons were taken for histopathological diagnosis, and 16S rDNA sequencing technology was used to detect the bacterial composition of colon contents.

　　Results The clinical results showed that the DSS group started to have soft stools from the 3rd day, the fecal occult blood was positive on the 5th day, and the body weight decreased; the TNBS group lost weight on the 2nd day, and 4 days before modeling, the fecal occult blood was positive. Necropsy showed that colon weights increased in both model groups, and only the DSS group had significantly shorter colons. Histopathologically, in the DSS group, the inherent structure of the colon ulcer was destroyed and the adjacent crypts expanded, and in the TNBS group, the crypt structure remained and the crypt cells were proliferated. There were differences in the characteristics of colonic flora disturbance between the two model groups. Compared with the control group, the abundance of Softwall and Cyanobacteria had no significant change in the DSS group but increased in the TNBS group (P<0.05); the abundance of Acidobacteria had no significant change in the DSS group but increased in the TNBS group (P<0.05). The TNBS group was significantly reduced (P < 0. 05); the abundances of Actinobacteria and Lactobacillus were decreased in the DSS group (P < 0. 05), but there was no significant change in the TNBS group; the abundance of Bacteroides in the DSS group increased and decreased significantly in the TNBS group (P<0.05).

　　Conclusion DSS and TNBS ethanol-induced UC models have both commonalities and their own characteristics in clinical symptoms, colonic histopathological damage characteristics and intestinal flora structure. The research results can provide some theoretical reference for animal model selection.