Effect Of High-altitude Hypoxia On Immune Function Of Dextran Sulfate Sodium Induced Ulcerative Colitis In Mice

Objective: To study the effect of high-altitude hypoxia on the immune function of mice with ulcerative colitis induced by dextran sulfate sodium(DSS)Methods: 40 Balb /c mice were used and randomly divided into four groups: Control group and DSS group to induce ulcerative colitis at Xining city(2260 m,582 mm Hg).Hypoxia group and DSS hypoxia group have been treated in a hypobaric chamber for up to 7 days at a simulated altitude of 5000 m.Flow cytometry,ELISA,and RT-PCT were used to measure the level of IL-4,IL-10,1L-17,TNF?,and INF-?,and H&E stain to study the morphological and pathological changes in colon tissue.Results: A successful ulcerative colitis has been established under Hypobaric hypoxia in an animal model of mice.Furthermore,the results have shown that the mice exposed to high altitude plains significantly increased the severity of ulcerative colitis,including the bodyweight loss and colon length decreased with the gross bloody feces and diarrhea.Furthermore,the concentrations of inflammatory cytokines of TNF-?,IFN-?,IL-17,and IL-10 in the spleen and mesenteric lymph node were shown to be significantly higher than those in the control group,and the expression of the m RNA of those cytokines within the colon significantly higher than the control group.Moreover,colon tissue myeloperoxidase activity significantly increased.Interestingly,Histopathology analysis showed that hypoxia increased the severity of DSS induced colitis in mice as compared to the control group.Conclusion: High altitude hypoxia aggravates the ulcerative colitis which destroying the colon tissue through an expansion of inflammatory cell infiltration and neutrophil activation.