血吸虫卵对小鼠三硝基苯磺酸肠炎的预防作用

Effect of schistosome ova on Trinitrobenzenesulfonic acidinduced colitis in mice

目的研究腹腔内注射血吸虫卵对小鼠三硝基苯磺酸(TNBS)肠炎的预防作用及对肠道上皮 Toll 样受体4(TLR4)表达的影响。方法 40只 BALB/c 小鼠随机分成正常对照组(10只);TNBS 肠炎组(20只);血吸虫卵组(10只)。评价小鼠病死率,肠黏膜病理表现,血浆肿瘤坏死因子(TNF)-α含量,免疫组化法、逆转录(RT)-PCR 法检测结肠 TLR4的表达。结果血吸虫卵组小鼠病死率低于 TNBS 肠炎组(20%vs70%,P<0.05),肠道炎症轻于 TNBS 肠炎组(Ameho 标准评分1.4±0.5 vs 4.2±0.6,P<0.01)。结肠 TLR4表达(TLR4/β-肌动蛋白吸光度比值):TNBS 肠炎组>血吸虫卵组>正常对照组(0.762±0.054 vs 0.325±0.029 vs 0.237±0.021,均 P<0.01)。结论腹腔内注射血吸虫卵可预防小鼠 TNBS 肠炎,可能与其下调结肠 TLR4表达有关。

Objective To investigate the effects of intraperitoneal injected schistosome ova on TNBS-induced colitis and on the intestinal TLR4 expression in mice. Methods 40 BALB/c mice were randomized into 3 groups： normal control group （10 mice）,TNBS group （20 mice） in which mice were exposed to trinitrobenzesulfonic acid （TNBS） and were induced with colitis, and the schistosome ova group （ 10 mice） in which mice were intraperitoneal injected with freeze-killed schistosome ova and later exposed to TNBS. The following variables were observed： mortality, pathological appearance of the colon, histological scoring of the specimen, serum TNF-α level , and intestinal TLR4 expression detected by RT-PCR and Immunohistochemistry. Results Mortality of schistosome ova group was lower than that of the TNBS group （20% vs 70%, P 〈 0. 05 ）. Inflammation of the mice colon in the schistosome ova group was less severe than that of the TNBS group（ 1.4 ±0. 5 vs 4. 2 ±0.6, P 〈0.01 ,Ameho criteria scoring）. TLR4 expression of colon was up-regulated in mice of TNBS group and down-regulated in schistosome ova group which was still higher than that of normal controls （ 0. 762 ± 0. 054 vs 0. 325 ± 0. 029 vs 0. 237 ± 0. 021, P 〈 0. 01 ）. Conclusion Intraperitoneal injected schistosome ova can obviously reduce TNBS-induced colitis in mice, which may be attributed to down-regulated TLR4 expression in colon.