| Objective: To explore transcription and translation levels of KRT1 and proinflammatory cytokines (tumor necrosis factor,TNF-a ; Interleukin, IL-1β) in dextran sulfate sodium (DSS) -induced experimental colitis.Methods:1, Sixty-seven male C57BL/6 mice were randomly grouped as fellow: control group(n=15), 2%DSS model group (n=15), 4%DSS model group (n=17), 6%DSS model group(n=20). The colitis model was established by administration of 2%、4%、 6%DSS for 7 days. Mice were sacrificed to obtain specimens at 8th day;2, Colitis was assessed by disease activity index(DAI), weight change, colonic injury/inflammation, colonic length/weight, splenic length /weight;3, The expression of KRT1, TNF-a, IL-1β in the colonic mucosa were detected by polymerase chain reaction (RT-PCR), Serum concentrations of KRT1, TNF-a, IL-1βwere detected using ELISA method;4,Statistics analysis was performed using SPSS to explore the expression correlations between KRT1 and TNF-α, IL-1β.Results:1,Compared with that in control group, with the increasing of the concentration ,body weight had significantly loss in DSS model group(P < 0.05); DAI score and the macroscopic observation score of colon injure significantly increased (0±0 vs 2.91±0.46 vs 3.75±0.23 vs 3.93± 0.15, P < 0.01; 0 ±0 vs 1.73±0.46 vs 3 ±0.53 vs 3.67±0.50;P < 0.01),accompanied with colonic length shortened (7.75cm±0.55cm vs 5.77cm±0.36cm vs 5.01cm±0.55cm vs 4.67cm±0.29cm ;P < 0.01),weight decreased (0.30g±0.06g vs 0.30g±0.03g vs 0.26g±0.03g vs 0.23g±0.02g,P < 0.01); splenic length increased (1.33cm±0.13cm vs 1.37cm±0.12cm vs 1.41cm±0.15cm vs 1.48cm ± 0.12cm,P < 0.05),weight increased (0.058g±0.016g vs 0.061g ± 0.015g vs 0.070g±0.037g vs 0.080g±0.02g,P<0.05);2, Compared with the control group, the serum concentrations of TNF-a and IL-1β were higher in DSS group, and the difference between the groups was statistically significant(22.05±3.43 vs 34.27±3.34 vs 60.18±3.37 vs 72.92±3.24; 200.59±7.62 vs 245.95±9.31 vs 276.92±14.81 vs 308.09±10.93;p<0.01).3,Compared with the control group, The expression of KRT1 in 2%, 4%, 6%DSS model group decreased in varying degrees(1.00±0.00 vs 0.86±0.07 vs 0.59±0.09 vs 0.42±0.03,p<0.01), and TNF- a, IL-1β were increased in different degree, the difference was statistically significant(1.00±0.00 vs 5.50±2.68 vs 15.25±2.86 vs 25.70±4.58; 1.00±0.00 vs 24.91±6.41 vs 39.88±5.72 vs 81.70±8.66,p<0.01).4, The expression of KRT1 was negatively correlated with TNF-α and IL-1βin colonic mucosa. (r=-0.846, r=-0.904, P < 0.01).Conclusions:1,DSS induced colitis model is safe and reliable,and is proportional to the concentration of drug;2,KRT1, TNF-α、IL-1β are involved in the pathogenesis of ulcerative colitis;3,KRT1 might be a new evaluation marker used for inflammation activity levels in UC. |
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