氧化应激条件下CD200对MG炎性反应的调控作用

目的探讨氧化应激条件下CD200如何参与调控MG（d＇胶质细胞）激活后的炎性反应。方法对原代培养的MG进行氧化应激处理，并利用急性分离的皮质神经元进行干预。“对照组”和“H2O2组”分别采用生理盐水和H2O2（100μmol／L）进行处理，“H2O2＋CD200组”在H2O2（100μmol／L）处理之前30min采用急性分离的神经元（约含1×10^6细胞）进行预处理。于处理后第0．5h、1h、2h、3h和4h时，采用Western blotting法对MG内p-p38 MAPK和IκB-α的蛋白表达量进行检测；以及第0h和72h时，采用ELISA法对培养介质内的TNF-α和IL-1β的含量进行检测。结果p-p38 MAPK和IκB—α的蛋白表达：“对照组”各时间点均无明显变化；“H2O2组”和“H2O2＋CD200组”0．5b时表达量亦基本相同；而3h时“H2O2组”p-p38 MAPK蛋白表达量明显高于“H2O2＋CD200组”；4h时“H2O2组”IκB-α的蛋白表达量明显低于“H2O2＋CD200组”。TNF-α和IL-1β含量：各组培养介质内0h时均未检出含有TNF-α和IL-1β；第72h时两细胞因子含量高低次序相同，即“对照组”〈“H2O2＋CD200”〈“H2O2组”。结论氧化应激条件下，CD200分子通过抑制MG胞质内p38 MARK的磷酸化，进而抑制了NF—κB的激活和炎性因子表达水平。

The Regulation of CD200 to the Inflammatory Reactions Provoked by Microglia under Oxidative Stress Condition

Objective The aim of the study was to explore the regulation roles of CD200 to the inflammatory reaction provoked by microglia（MG） under oxidative stress in vitro. Method The cultured microglia cells were treated with H202 in vitro, and co-cultured with the neurons isolated from cerebral cortex. Control group and H2O2-group were treated with saline and H2O2（100 μmol/L） respectively. H2O2＋CD200-group was treated with neurons （1×10^6 cells）, 30 mins before H2O2 （100 μmol/L） administration. The expression levels of p-p38 MAPK and IκB-α were detected with Western blotting at 0.5, 1, 2, 3, and 4 h post treatment. The TNF-α and IL-1β contents in the culture medium were assayed using ELISA kit at Oh and 72 h post treatment. Result The levels of p-p38 MAPK and IκB-α remained unchanged in the control group and at 0.5 h post treatment of both H2O2-group and H2O2＋CD200-group. The level of p-p38 MAPK of H2O2-group was higher than that of H2O2＋CD2OO-group at 3 h post treatments. However the level of IκB-α of H2O2-group was obviously lower than that of and H2O2＋CD200-group at 4 h post treatment. TNF-α and IL-1β could not be detected in the culture medium of all groups at 0 h. At 72 h post treatment, the amount TNF-α and IL-1β detected in the culture medium in the control group 〈 H2O2＋CD200-group 〈 H202-group. Conclusion Under oxidative stress, through inhibiting the phosphorylation of p38 MAPK, CD200 suppressed the activation of NF- κB and expression of pro-inflammatory eytokines in microglia.