中文摘要：

【目的】本研究通过体外实验,分析植物乳杆菌NDC75017对免疫相关基因白细胞介素6（il-6）表达的影响,并进一步揭示其机制。【方法】植物乳杆菌NDC 75017作用于Caco-2细胞0、2、4、6、8、10和12 h,采用Real Time PCR方法检测il-6基因和toll样受体2（tlr2）的表达。植物乳杆菌NDC 75017与Caco-2细胞共培养0、0.5、1、2和4 h,用western blot方法检测NF-κB的磷酸化水平;NF-κB的特异性抑制剂PDTC预处理Caco-2细胞30 min后,再加入植物乳杆菌NDC 75017作用2 h,用Real Time PCR方法检测il-6基因及tlr2的表达量。【结果】植物乳杆菌NDC 75017诱导Caco-2细胞中il-6和tlr2基因的表达,并且分别在诱导8 h和6 h时表达量达到最大。植物乳杆菌NDC 75017能够快速诱导NF-κB的磷酸化作用,在加入其特异性抑制剂PDTC后,il-6和tlr2基因的表达显著下降。【结论】植物乳杆菌NDC 75017能通过tlr2介导的NF-κB信号通路来诱导细胞因子il6短暂性的表达。

英文摘要：

[Objective] We tested the expression of immune-related gene interleukin 6（il-6） in vitro to understand the influence from Lactobacillus plantarum NDC 75017 on host cells and further to reveal the regulatory mechanism.[Methods] Caco-2 cells were cocultured with L.plantarum NDC 75017 for 0,2,4,6,8,10 and 12 h,the total RNA were extracted;then the expressions of il-6 and tlr2 genes were analyzed by Real Time RT-PCR.The phosphorylation level of NF-κB was analyzed by Western Blot after the Caco-2 cells stimulation with L.plantarum NDC 75017 at 0,0.5,1,2 and 4 h.Caco-2 cells were pretreated with pyrrolidine dithiocarbamate for 30 min before being treated with L.plantarum NDC 75017 for 2 h,then the total RNA was extracted and the expressions of il-6 and tlr2 genes were analyzed by Real Time RT-PCR.[Results] Lactobacillus plantarum NDC 75017 could induce the expressions of il-6 and tlr2 in Caco-2 cells,the il-6 and tlr2 expressions peaked at 8 h and 6 h after cocultured with L.plantarum NDC 75017.L.plantarum NDC 75017 could rapidly activate the phosphorylation of NF-κB,and the expressions of il-6 and tlr2 were decreased notably after pretreated with pyrrolidine dithiocarbamate.[Conclusion] L.plantarum NDC 75017 could up-regulate and then down-regulate the expression of il6 through rapidly activating tlr2-mediated NF-κB signaling pathway in Caco-2 cells.