2. The peripheral blood Th1, Th17 cell numbers are remarkable higher in IBD patients, which suggests that there are important relations on the changes of proportion of Th1 and Th17 cells with IBD pathogenesis and progression. Key Word(s): 1. IBD; 2. MDSC; 3. Th1 cells; 4. Th17 cells; Presenting Author: CHENWEI CHANG Additional Authors: LIYUE QIN, GAO NAN, ZHANGGUANG BO Corresponding Author: CHENWEI CHANG Affiliations: Department of Gastroenterology. Objective: To tentative approach to the therapeutic effects and mechanisms of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] against DSS (dextran sulfate sodium)-induced ulcerative colitis (UC) in mice. Methods: Thirty

BALB/c mice were randomly assigned small molecule library screening into five groups: group A (control group, n = 6), group B (model group, n = 6), group C (low-dose intervention group, n = 6), group D (moderate-dose intervention group, n = 6), group E (large-dose intervention group, n = 6). drinking 5% DSS solution for seven days in groups B, C, D, E were induced UC model, while group A was given equal volume of distilled water. As to start of the DSS exposure, groups C, D, E were intraperitoneally injected on 1, 3, 5, and 7 days to each mouse with low dose (50 ng), medium dose (100 ng), high-dose (200 ng) of 1,25(OH)2D3, respectively. While group A, B were intraperitoneally injected with sterile soybean oil soluble drug

carrier. On 8 days after molding, all mice were executed. The disease activity index (DAI) in mice were estimated by selleck general

observation and histopathological score (HPS) were calculated by routine pathologic examination. The expressions of IFN-γmRNA, IL-17 mRNA and IL-21 mRNA in distal colon, and IFN-γ, IL-17 and IL-21 of spleen lymphocytes of mice were measured by RT-PCR or by flow cytometry, and the protein expression of IFN-γ, IL-17 and IL-21 in distal colon of mice were measured by immunohistochemistry. Results: (1) The DAI heptaminol and HPS in the model group (B group) were significantly higher than in group A (7.33 ± 1.03 vs 0.33 ± 0.52, 12.00 ± 0.63 vs 0.17 ± 0.41, P < 0.01). The DAI (2.83 ± 0.40, 2.83 ± 0.75, 2.33 ± 0.52, respectively) and HPS (10.83 ± 0.98, 7.50 ± 0.84, 6.67 ± 0.52, respectively) in the three intervention groups were significantly decreased than in group B (P < 0.01). (2) The expressions of IFN-γmRNA, IL-17mRNA and IL-21mRNA in group B (3.11 ± 0.24, 1.38 ± 0.38, 3.32 ± 0.16, respectively) were significantly higher than in group A (1.38 ± 0.16, 0.52 ± 0.15, 1.47 ± 0.19, respectively)(P < 0.01), and were significantly lower in group C (2.48 ± 0.21, 0.75 ± 0.14, 0.72 ± 0.19, respectively), group D (2.02 ± 0.22, 0.56 ± 0.16, 0.73 ± 0.16, respectively), group E (2.00 ± 0.20, 0.53 ± 0.19, 0.76 ± 0.09, respectively) (P < 0.01). The expressions of IFN-γ, IL-17 of spleen lymphocytes in mice were significantly higher in group B [(58.98 ± 3.