NF-κB信号通路在异丙酚抑制脂多糖诱导RAW264．7细胞诱导型一氧化氮合酶基因表达上调中的作用

Role of NF-κB signaling pathway in propofol-induced suppression of up-regulation of inducible nitric oxide synthase gene expression in LPS-stimulated RAW264.7 cells

目的探讨NF-κB信号通路在异丙酚抑制脂多糖（LPS）诱导RAW264．7细胞诱导型一氧化氮合酶（iNOS）基因表达上调中的作用。方法体外培养RAW264．7细胞，以5×105／ml密度接种于6cm培养皿（3ml／皿）或6孔板（2ml／孔），采用随机数字表法，将其随机分为3组（n=18）：正常对照组（C组）、LPS组（L组）和12S＋异丙酚（LP组）。C组不做任何处理；L组和LP组均加入1μg／mlLPS，LP组于加入LPS前2h加入50μmol／L异丙酚。于LPS孵育30min时，每组取6皿和6孔，收集细胞，分别采用免疫印迹法测定磷酸化IxB激酶（p-IKK）和NF．KB活性；于LPS孵育6h时，每组取6皿，收集细胞，测定iNOSmRNA表达。结果与C组比较，L组p-IKK和iNOSmRNA表达上调，NF-κB活性升高（P〈0．05）；与L组比较，LP组p-IKK和iNOSmRNA表达下调，NF-κB活性降低（P〈0．05）。结论NF-κB信号通路参与了异丙酚抑制脂多糖诱导的RAW264．7细胞iNOS基因表达上调。

Objective To investigate the role of nuclear factor-kappa B （NF-κB）signaling pathway in propofol-induced suppression of up-regulation of inducible nitric oxide synthase （iNOS） gene expression in LPS- stimulated RAW264.7 cells. Methods RAW264.7 cells were purchased from cell bank of Chinese Academy of Sciences and cultured in DMEM culture medium containing 10% fetal bovine serum. The cells were seeded in 6 cm diameter dishes （3 ml/dish） or in 6-well plates （2 ml/well） with a density of 5 × 10^5/ml and randomly divided into 3 groups （ n = 18） ： normal control group （group C）, group LPS （group L）and group LPS ＋ propofol （group LP）. The cells were incubated with LPS 1 μg/ml in groups L and LP. Propofol 50 μmol/L was added to the culture medium at 2 h before LPS in group LP. Cells were harvested at 30 min after being stimulated with LPS. Phosphorylation of IκB kinase（p-IKK） and NF-κB activity were detected by Western blot. The expression of iNOS mRNA was determined after 6 h exposure of the cells to LPS. Results LPS significantly up-regulated the expression of p-IKK and iNOS mRNA and increased NF-κB activity in group L as compared with group C. Propofol pretreatment siguificandy attenuated the effects of LPS on p-IKK, iNOS mRNA expression and NF-κB activity. Conclusion NF-κB signaling pathway is involved in the propofol-induced suppression of up-regulation of iNOS mRNA expression in LPS-stimulated RAW264.7 ceils.