NF-κB信号通路对BLP耐受巨噬细胞iNOS表达的影响

目的　通过检测细菌脂蛋白（BLP）耐受巨噬细胞感染细菌时诱导型一氧化氮合酶（iNOS）表达情况及其表达是否受NF-κB信号通路调控，探讨BLP耐受巨噬细胞对细菌清除能力增强的机制。 方法     比较BLP耐受和非耐受（Naive）小鼠骨髓来源的巨噬细胞（BMM）对大肠杆菌的吞噬及杀灭情况，评价BLP耐受巨噬细胞的细菌清除能力；用定量PCR技术检测BLP耐受的BMM内iNOS mRNA表达情况和细胞免疫荧光技术观察p65从胞质向胞核的移位情况；最后观察抑制NF-κB通路活化对iNOS mRNA表达的影响。    结果     BLP耐受巨噬细胞吞噬细菌和杀灭细菌的能力较Naive细胞显著增强（P<0.05）；iNOS mRNA表达水平较Naive细胞显著（P<0.05）；如果抑制BLP耐受巨噬细胞NF-κB通路活化对iNOS mRNA表达有显著影响（P<0.05）。    结论     本研究结果提示细菌脂蛋白耐受通过NF-κB通路活化增强细菌感染巨噬细胞iNOS表达。

The effect of NF-κB signaling pathway on iNOS expression in BLP-tolerized macrophages

Objective　In order to explore mechanisms underlying enhanced bacterial clearance of BLP-tolerized macrophages，we detected the expression of inducible nitric oxide synthase (iNOS) and investigated whether this expression was regulated by NF-κB signaling pathway in BLP-tolerized macrophages to bacterial infection.　Methods 　Through comparison of the phagocytosis and intracellular bacterial killing of E.coli between Naive and BLP-tolerized mice bone marrow-derived macrophages (BMMs), we evaluated the bacterial clearing capability of BLP-tolerized macrophages. Next, the mRNA level of iNOS in BLP-tolerized macrophages was detected by real-time PCR, and the translocations of p65 from cytoplasm to nucleus were shown by immunofluorescence.Finally, the activation of NF-κB signaling pathway was inhibited and the mRNA expression of iNOS in BLP-tolerized BMMs were observed.　Results　Compared to Naive macrophages, the phagocytosis and intracellular bacterial killing of BLP-tolerized macrophages were significantly enhanced (P<0.05). The mRNA level of iNOS in BLP-tolerized macrophages was significantly increased (P<0.05), which could be significantly affected when the activation of NF-κB signaling pathway was inhibited (P<0.05).　Conclusion　The study suggests that iNOS expression increases through the activation of NF-κB signaling pathway in BLP-tolerized macrophages to bacterial infection.