中文摘要：

目的 了解稀土元素镧对内毒素／脂多糖（LPS）诱导的小鼠腹腔巨噬细胞（Mφ）核因子KB（NF-κB）活化的影响，并探讨其机制。方法分离培养小鼠腹腔Mφ，分为：空白对照组，无刺激因素：LPS组，用1μg／mlLPS刺激30min；镧离子（La^3＋）组，用2，5μmol／L La^3＋刺激30min；La^3＋＋LPS组，先后用2，5-μmol／L La^3＋、1μg／ml LPS各刺激30min；La^3＋／L PS组，2．5μmol／L La^3＋刺激30min后，洗涤细胞，再加入1μg／ml LPS刺激30min。采用细胞免疫荧光染色法观察NF-κB在各组细胞中的分布与表达；酶联免疫吸附测定（ELISA）法检测胞核中NF-κB／p65蛋白活性；蛋白质印迹法检测细胞核内NF-κB／p65蛋白及胞质中核因子抑制蛋白α（IκBα）的表达量。ELISA法测定各组细胞培养上清液中肿瘤坏死因子α（TNF-α）的含量。结果 （1）免疫荧光染色显示，空白对照组、La^3＋组、La^3＋＋LPS组和La^3＋／LPS组M小绿色荧光多分布于胞质，胞核荧光强度分别为42±7、73±30、48±11和67±19；LPS组绿色荧光集中于胞核，荧光强度为116±14，明显高于其余4组（P〈0.01）。（2）胞核NF-κB／p65蛋白活性：LPS组吸光度值为0．435±0．066，与空白对照组（0．048±0．027）、La^3＋组（0．062±0．049）、La^3＋＋LPS组（0.066±0.031）、La^3＋／LPS组（0．108±0.017）比较．明显偏高（P〈0．01）。（3）LPS组M由胞核NF-κB／p65蛋白表达水平明显高于其余4组，胞质IκBα蛋白表达水平明显低于其余4组。（4）TNF-α含量：La^3＋组培养上清液中TNF-α含量低于试剂盒检测下限（25pg／m1）及空白对照组（P〈0.05），La^3＋＋LPS组和La^3＋／LPS组低于LPS组（P〈0．01），但高于空白对照组。结论 LPS可激活小鼠腹腔M由NF-κB／p65核移位，并使胞核中NF-κB／p65的表达量和活性升高、胞质IκBα蛋白表达下调，导致TNF-α分泌增多。镧可抑制上?

英文摘要：

Objective To investigate the influence of lanthanum on lipopolysaccharide（LPS） induced NF-κB activation in murine peritoneal macrophage. Methods Peritoneal macrophages were isolated and cultured by routine method, and randomly divided into 5 groups： i. e, control group, LPS group（ with LPS stimulation for 30 rain） , La^3＋ group （with 2.5μmol/L La^3＋ group for 30 min） , La^3＋ ＋ LPS group（ with 1 μg/ml LPS stimulation for 30rain after 30 rain incubation with DMEM-FI2 containing 2.5μM of lanthanum. ） ; La^3 ＋/LPS group （ with 2.5 μM of lanthanum stimulation for 30min, and then with 1μg/ml of LPS for another 30 min after lanthanum was removed. The location of NF-κB p65 subunit （ NF-κB/p65 ） in Mφ was detected by immunofluorescence and fluorescence microscope. The binding activity of NF-κB/p65 with DNA in nuclei was detected by TransAMTM NF-κB/p65 Transcription Factor assay kit. Meanwhile, the expression of NF-κB/p65 in nuclei, as well as IκBα in cytoplasm was measured by Western blotting. TNF-α content in culture supernatant were detected by ELISA. Results （1） The green fluorescence in control, La^3＋ ,La^3＋ LPS and La^3＋/LPS groups was mainly located in cytoplasm, while that in LPS group was loca ted in nuclei. The fluorescent intensity in LPS group was （116 ± 14） , which was obviously higher than that in other4 groups （42 ±7,73 ±30,48 ±ll and 67±19, respectively, P 〈0.01）. （2） The IκBα protein level in cytoplasm in control（0.048±0.027） , La^3＋ group （0.062 ±0.049） , La^3 ＋ LPS group（0. 066± 0. 031 ） and La^3＋/LPS group（0. 108 ±0. 017 ）was significantly lower than that in LPS group （0. 435±0. 066, P 〈 0.01 ）. （3） The expression and activation of nucleus p65 protein in Mφ in LPS group was obviously higher than the other 4 groups, but changes in the IκBα expression between LPS group and other 4 groups was of controversy. （4） TNFa level in the culture supernatant in La^3＋ group was low