益生菌VSL#3对DSS大鼠结肠炎TLR4-NF-κB通路的调节作用

目的 阐明益生菌VSL#3对硫酸葡聚糖钠(DSS)诱导结肠炎大鼠TLR4-NF-κB通路的影响，深入探讨VSL#3对结肠黏膜炎症免疫调控机制。方法 将33只Sprague-Dawly大鼠(SD大鼠)分为正常组、DSS造模组以及益生菌治疗组。5% DSS溶液自由饮用一周，构建溃疡性结肠炎模型。观察和评价大肠黏膜的组织学损伤，计算DAI评分以及病理学评分；使用real-time PCR检测结肠组织TLR4、NF-κB、TNF-α、IL-1β mRNA的表达水平；Western-Blot检测TLR4、NF-κB蛋白的表达水平；应用酶联免疫吸附测定(ELISA)检测血清中TNF-α和IL-1β的表达。结果 益生菌治疗组DAI评分、病理学评分均低于DSS造模组(P<0.05)；益生菌治疗组大鼠结肠组织中TLR4、NF-κB、TNF-α、IL-1β的mRNA水平与DSS造模组相比表达下调，差异具有统计学意义(P＜0.05)；与DSS造模组相比，益生菌治疗组SD大鼠结肠组织TLR4、NF-κB p65蛋白水平下调，血清TNF-α、IL-1β表达水平降低，差异具有统计学意义(P＜0.05)。结论 益生菌VSL#3可能是通过抑制TLR4-NF-κB通路，发挥其抑制免疫，减轻炎症反应的作用，从而达到治疗溃疡性结肠炎的目的。

The regulating effects of probiotics VSL#3 on the TLR4-NF-κB pathway in rats with DSS-induced colitis

Objective To elucidate the effects of probiotic VSL#3 on the TLR4-NF-κB pathway in rats with DSS-induced colitis, and to further investigate the immunoregulatory mechanism of VSL#3 on colon mucosa inflammation. Methods 33 Sprague-Dawly rats (SD rats) were randomly divided into three groups. Those rats were given access to 5% dextran sulfate sodium (DSS) solution ad libitum for a week to build the model of experimental acute enteritis. Observe and evaluate the histological damage of colorectal mucosa, calculate the DAI score and pathological score. Real-time PCR was used to detect the mRNA levels of TLR4, NF-κB, IL-1β, and TNF-α in the rat colon mucosa. Western-Blot was used to detect the protein levels of TLR4 and NF-κB in colon mucosa. Serum IL-1β and TNF-α in rats were detected by ELISA. Results DAI scores and pathology scores in probiotics groups were lower than those in the model group (P<0.05). The mRNA levels of TLR4, NF-κB, TNF-α, and IL-1β in the colonic tissue of the probiotic treatment group were down regulated compared with those of the DSS mod model, and thedifferences were statistically significant (P<0.05). Compared with the DSS model group, the levels of TLR4 and NF-κB p65 protein in the colon of the SD rats treated with probiotics were decreased, and the levels of serum TNF-α and IL-1β were decreased, the differences were statistically significant (P<0.05). Conclusion VSL#3 may achieve the goal of treating ulcerative colitis by inhibiting the TLR4-NF-κB pathway so as to inhibit immune and suppress inflammatory