Objective: To investigate the effect of cysteine protease inhibitor derived from Schistosoma japonicum (SjCystatin) on dextran sodium sulfate (DSS)-induced acute ulcerative colitis in mice.
Methods: Eighteen C57BL/6 mice were randomly divided into three groups: a control group treated with PBS (Group A), a DSS-induced-colitis group treated with PBS (Group B), and a DSS-induced-colitis group treated with SjCystatin (Group C). Colitis was induced in mice by giving 3% DSS orally for 7 days. During this period, the mice were daily injected with 10 μg of SjCystatin or PBS only as a control intraperitoneally. The mice were monitored daily for their clinical manifestations and given scores based on disease activity index (DAI). The severity of colonic inflammation was monitored by the macroscopic score and pathological change. The cytokine profile including TNF-α, IL-4, IL-6 and IL-10 in the supernatants of colon homogenate was detected by ELISA.
Results: Compared with Group A (0.50 ± 0.28), the DAI score increased significantly in Group B (9.30 ± 1.30) (F = 86.86, P < 0.01), with remarkable pathological damages seen in colon tissues. and the levels of TNF-α and IL-6 were (321.33±67.01) and (403.58 ±180.51) pg/mL. The DAI score significantly reduced in Group C (6.67±1.57) as compared to Group B (F = 86.86, P < 0.01), with improvements in the macroscopic and microscopic pathology in mouse colon specimens. As compared to Group B, the levels of TNF-α [(188.14 ± 40.14) pg/mL] and IL-6 ([ 209.71 ± 48.47) pg/mL] significantly decreased (F = 17.46 and 9.89, both P < 0.01).
Conclusions: SjCystatin has a significantly inhibitory effect for alleviating DSS-induced acute ulcerative colitis in C57BL/6 mice.
[摘要] 目的 探讨日本血吸虫半胱氨酸蛋白酶抑制剂 (Schistosoma japonicum cysteine protease inhibitor, SjCystatin) 对葡 聚糖硫酸钠 (Dextransulphate sodium, DSS) 诱导的小鼠急性溃疡性结肠炎的抑制作用。方法 18只雌性C57BL/6小鼠随 机分为3组: A组为对照组, B组为肠炎组, C组为SjCystatin治疗组。A组给予蒸馏水, B、C组连续饮用3%DSS溶液7 d诱 发肠炎; C组每天经腹腔注射10 μg SjCystatin, A和B组注射PBS。观察各组小鼠临床表现, 进行临床疾病活动指数 (Dis- ease activity index, DAI) 评分。第7天处死小鼠, 观察结肠大体及组织病理改变。同时提取小鼠结肠组织匀浆, 采用酶联 免疫吸附实验 (ELISA) 测定其上清中肿瘤坏死因子-α (TNF-α) 、白细胞介素-4 (IL-4) 、IL-6及IL-10水平。结果 与A组 ([ 0.50 ± 0.28) 分]相比, B组小鼠DAI评分 ([ 9.30 ± 1.30) 分]明显增加, 建模后小鼠结肠病理损伤显著, 结肠组织匀浆上清 中TNF-α为 (321.33 ± 67.01) pg/mL, IL-6为 (403.58 ± 180.51) pg/mL, 均明显上升。C组小鼠DAI评分为 (6.67 ± 1.57) 分, 显著下降 (F =86.86, P <0.01); 小鼠结肠大体及组织病理明显缓解, 结肠组织匀浆上清中TNF-α为 (188.14±40.14) pg/mL, IL-6为 (209.71 ± 48.47) pg/mL, 均显著下降 (F = 17.46、9.89, P < 0.01) 。结论 SjCystatin对DSS诱导的C57BL/6小鼠急性溃疡 性结肠炎有抑制效果。.
Keywords: Cysteine protease inhibitor; Dextransulphate sodium; Schistosoma japonicum; Ulcerative colitis.