特定双歧杆菌菌株对炎症性肠病小鼠的影响

Effect of specific Bifidobacteria strain on the inflammatory bowel disease mice

摘要:

为了观察特定双歧杆菌菌株对葡聚糖硫酸钠(DSS)诱导的Balb/c 小鼠结肠炎的影响, 探讨该双歧杆菌菌株对炎症性肠病(IBD)的防治作用及其可能机制。将小鼠分为3 组: 正常对照组、模型组(DSS 组)、实验组(DSS+Bf 组)。用已挑选好的双歧杆菌菌株预先处理小鼠4 周后, 用4% DSS 溶液诱导急性结肠炎。实验结束后, 检测每组小鼠结肠的长度及结肠炎炎症程度, 利用半定量RT-PCR 法检测小鼠肠道派伊尔结细胞中IL-10 的表达, 利用免疫组化实验检测肠道黏膜中IL-10 分泌阳性细胞。结果实验组小鼠结肠的平均长度为7.8 cm±0.21 cm, 虽较正常对照组(9.1 cm±0.82 cm)缩短, 但较模型组(6.8 cm±0.31 cm)其缩短程度减少; 结肠炎炎症程度肉眼评分结果: 模型组和实验组分别为8.6±0.24 分和6.6±0.68 分, 两组之间均有显著性差异(P<0.05), 显微镜下评分结果为实验组(6.8±0.73 分)较模型组(8.8±0.37 分)明显减少(P<0.05); 实验组小鼠肠道派伊尔结细胞IL-10 的表达和肠道黏膜IL-10 分泌阳性细胞数明显多于模型组。该实验所用的双歧杆菌菌株减轻了DSS 诱导的小鼠肠道炎症反应, 并且增强了肠道免疫细胞的IL-10 的表达及分泌。

Abstract:

In the present paper we investigated the effects of specific bifidobacteria strain as supplementation on acute inflammatory bowel disease (IBD) induced by dextran sulfate sodium (DSS) and the possible mechanism was also discussed. Mice were divided into three groups as control, DSS, and experiment (DSS+Bf) group. The mice in DSS group were fed with 4% DSS (W/V) solution for 7 days to induce colitis, and the mice in DSS+Bf group, were then given bifidobacteria by oral gavage for next 4 weeks. Boththe colonic lengths and the magnitude of colonic inflammation were measured for three groups. Furter, expression of IL-10 mRNA in Peyer’s patch (PP) cells and secretion of IL-10 in intestinal mucosa were also assessed by reverse transcription- polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. It was found that the average colonic length observed in the DSS+Bf group was shorter than those in the control group but longer than those in the DSS group. Both macro-and micro-disease scorring showed that the values of the DSS+Bf goup significantly decreased compared with the DSS group, while both the expression of IL-10 mRNA in PP cells and the IL-10 positive cells in intestinal mucosa of the samples in the DSS+Bf group were also significantly higher than those of DSS group. It is obvious that the bifidobacteria strain involved in the present studies could prevent the DSS-induced murine colitis and improve the expression levels of anti-inflammatory cytokine IL-10 in intestinal mucosa.