纳豆菌糖肽对RAW264.7巨噬细胞NF-κB核转位的影响

Effect of Bacillus natto Glycopeptide on Nuclear Translocation of Nuclear Factor-κB in RAW264.7 Macrophages

摘要:

本文采用免疫荧光法分析纳豆菌糖肽(BNGP)对RAW264.7巨噬细胞NF-κB p65核转位的影响，Western blot检测BNGP对NF-κB p65在细胞质及细胞核的表达的影响，流式细胞术分析BNGP对LPS-FITC与细胞表面受体结合的影响。结果显示：62.5~500 μg/mL BNGP组的发生NF-κB p65核转位的细胞比例均极显著高于空白对照组；高浓度BNGP（500 μg/mL）能显著减少由LPS诱导发生NF-κB p65核转位的细胞比例，而低浓度BNGP（≤250 μg/mL）则与LPS组无显著差异。62.5~500 μg/mL BNGP单独作用于细胞时，NF-κB p65在细胞质中表达量下降而在细胞核中表达量上升，表明BNGP可促进巨噬细胞NF-κB p65从胞质转移入核；62.5~500 μg/mL BNGP与LPS共同作用时，则NF-κB p65在细胞质中表达量上升而细胞核中表达量下降，表明BNGP可抑制LPS诱导的NF-κB p65大量从胞质转移入核。62.5~500 μg/mL BNGP均能减少LPS-FITC 结合到巨噬细胞上的量，其中500 μg/mL BNGP作用极显著，表明BNGP对LPS-FITC与细胞表面受体的结合具有干扰作用。

Abstract:

The effect of Bacillus natto glycopeptide (BNGP) on the nuclear translocation of nuclear factor (NF)-κB p65 into the nucleus of RAW264.7 macrophages was studied using immunofluorescence; its effect on NF-κB p65 expression in the cytoplasm and nucleus was detected by western blot, while its effect on fluorescein isothiocyanate-lipopolysaccharide (LPS-FITC) binding to cell receptors was determined by flow cytometry. The results showed that the percentage of the cells with NF-κB p65 nuclear translocation in 62.5~500 μg/mL BNGP groups was significantly higher than that in the control group. High-dose BNGP (500 μg/mL) significantly reduced the percentage of cells with NF-κB p65 nuclear translocation induced by LPS and no significant changes were found between the low dose (≤ 250 μg/mL) BNGP and LPS groups. When macrophages were treated with 62.5~500 μg/mL BNGP alone, NF-κB p65 expression level increased in the nucleus and decreased in the cytoplasm, suggesting that BNGP promoted the translocation of NF-κB p65 from cytoplasm to nucleus. When macrophages were treated with 62.5~500 μg/mL BNGP and LPS, the expression level of NF-κB p65 increased in the cytoplasm and decreased in the nucleus, suggesting that BNGP inhibited the LPS-induced nuclear translocation of NF-κB p65 from the cytoplasm to the nucleus in RAW264.7 cells. BNGP also reduced the amount of LPS-FITC bound to macrophages at doses ranging from 62.5 to 500 μg/mL, where 500 μg/mL BNGP showed a significant effect, indicating that BNGP interferes with the binding of LPS-FITC to macrophages.