论文部分内容阅读
目的观察小胶质细胞中是否存在核苷酸结合寡聚化结构域蛋白2(NOD2)介导的免疫耐受现象,并探讨其与Caspase-1的关系。方法分别采用不同浓度的胞壁酸二肽(MDP)或肺炎链球菌刺激小胶质细胞24 h,Western blotting检测各组NOD2和核因子κB(NF-κB)的表达情况,ELISA检测白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)的表达情况;用MDP(100μg/m L)分别预刺激细胞0、3、24 h后再用同浓度MDP刺激24 h,用ELISA检测IL-6和TNF-α的表达量;Caspase-1活性被ATP激活或被其抑制剂抑制后检测IL-6和TNF-α的变化情况。结果与无刺激处理相比,MDP或肺炎链球菌刺激小胶质细胞24 h后,NOD2、NF-κB、IL-6和TNF-α的表达量均明显增加(P<0.05);MDP分别预刺激细胞0、3、24 h后再刺激24 h,发现预刺激3 h和24 h的细胞IL-6和TNF-α的表达量均低于预刺激0 h;通过ATP激活Caspase-1活性可抑制细胞IL-6和TNF-α的表达,抑制Caspase-1活性可促进IL-6和TNF-α的表达。结论长时间MDP刺激可以诱导小胶质细胞的免疫耐受现象,此现象与Caspase-1的活性具有一定关系。
Objective To observe the existence of nucleotide-binding oligomerization domain 2 (NOD2) -mediated immune tolerance in microglia and to explore its relationship with Caspase-1. Methods The microglial cells were stimulated with different concentrations of MDP or Streptococcus pneumoniae for 24 h respectively. The expressions of NOD2 and NF-κB in each group were detected by Western blotting. The levels of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected by flow cytometry. Cells were pre-stimulated with MDP (100μg / mL) for 0,3,24 h and then stimulated with the same concentration of MDP for 24 h. The expression of IL-6 and TNF-α were detected. The activity of Caspase-1 was activated by ATP or inhibited by inhibitors. The changes of IL-6 and TNF-α were detected. Results Compared with non-stimulated group, the expression of NOD2, NF-κB, IL-6 and TNF-α significantly increased after MDP or S. pneumoniae stimulation of microglia for 24 h (P <0.05) The cells were stimulated for 24 h at 0, 3 and 24 h after stimulation, and the expression of IL-6 and TNF-α in cells pre-stimulated for 3 h and 24 h were lower than that of pre-stimulation for 0 h. Caspase-1 activation by ATP was Inhibit the expression of IL-6 and TNF-α, and inhibit the activity of Caspase-1 to promote the expression of IL-6 and TNF-α. Conclusion MDP stimulated for a long time can induce the immune tolerance of microglia, which is related to the activity of Caspase-1.