Pathogenic effect of bacterial flagellin in TNBS-induced colitis in mice / 中国病理生理杂志

ABSTRACT

AIM:To detect the expression of CBir1 in the serum and colon tissue and mast cell degranulation in the tissue of 2,4,6-trinito-benzene-sulfonic acid ( TNBS)-induced colitis in mice with different interventions. ME-THODSSPF male BALB/c mice were randomized into 6 groups (12 mice in each group)normal control group, normal saline group, 50% alcohol group, 50% alcohol+TNBS group, 50% alcohol+TNBS+lipopolysaccharide (LPS) +ovalbu-min (OVA) group and 50% alcohol+TNBS+ketotifen group. Corresponding treatment was given to each group, and the disease activity index (DAI) of the mice was evaluated. The mice were sacrificed on day 22 after treatment. The colon tis-sues were evaluated by histological index (HI) scoring. Serum concentrations of anti-CBir1, mast cell tryptase (MCT) and histamine were measured by ELISA. The expression of CBir1, toll-like receptor 5 (TLR5) and MCT in the colon tissues was detected by immunohistochemistry. RESULTS:Compared with the normal control group, the DAI score, HI score and CBir1, anti-CBir1, MCT, TLR5, histamine concentrations in colon tissues and serum were all significantly higher in 50% alcohol+TNBS group, 50% alcohol+TNBS+ketotifen group and 50% alcohol+TNBS+LPS+OVA group (P<0.05). The DAI score, HI score and anti-CBir1, CBir1, MCT, histamine levels in 50% alcohol+TNBS group were lower than those in 50% alcohol+TNBS+LPS+OVA group (P<0.05). The DAI score, HI score and anti-CBir1, TLR5, hista-mine, CBir1 Levels in 50% alcohol+TNBS group were higher than those in 50% alcohol+TNBS+ketotifen group ( P<0.05). Normal saline group and 50% alcohol group had no statistically significant difference in comparison with normal control group. In TNBS model group, serum concentration of anti-CBir1 was positively correlated with MCT concentration (r=0.648, P<0.01) and histamine concentration (r=0.751, P<0.01). CONCLUSION:The heavier degree of in-flammation in TNBS-induced colitis, the higher levels of the CBir1 and the degranulation of mast cells. There is a positive correlation between the expression of CBir1 and the degranulation of mast cells in TNBS-induced colitic mice.