脑源性神经营养因子在ATP活化BV2小胶质细胞中的作用

摘要

目的：探讨脑源性神经营养因子（BDNF）在腺苷三磷酸（ATP）激活BV2小胶质细胞过程中的作用。方法以不同浓度ATP孵育BV2小胶质细胞后，采用Western blot法定量检测细胞中CD11b、BDNF表达水平，ELISA测定上清液中肿瘤坏死因子α（TNF‐α）的分泌水平。再将BV2细胞用不同浓度BDNF清除剂原肌球蛋白相关激酶B（TrkB）／Fc预处理后给予ATP孵育，检测细胞中CD11b、BDNF表达水平的变化及上清液中 TNF‐α的分泌水平。最后加入外源性重组BDNF ，检测细胞内CD11b表达和上清液中TNF‐α的水平变化。结果 ATP孵育BV2细胞后，细胞内 CD11b、BDNF及上清液中 TNF‐α水平在一定范围内呈剂量时间依赖性增加。加入TrkB／Fc后，BV2细胞中 CD11b、BDNF及上清液中TNF‐α表达水平在一定范围内呈剂量和时间依赖性降低。加入外源性BDNF后，细胞内CD11b及上清液中TNF‐α水平又出现增加。结论 BV2小胶质细胞活化后细胞内BDNF增多，外源性补充BDNF可激活小胶质细胞，BDNF在小胶质细胞的活化过程中可能发挥了重要作用。%Objective To study the effect of brain‐derived neurotrophic factor (BDNF) in the process of adenosine triphos‐phate (ATP) activating BV2 microglia .Methods BV2 microglia was cultured by adding different concentrations of ATP .Then the expression level of intracellular CD11b and BDNF and the secretion level of TNF‐α in the supernatant were quantitatively deter‐mined by Western blot .BV2 microglia was treated by different concentrations of BDNF scavenger tyrosine kinase receptors B (TrkB)/Fc and incubated by ATP .The expression level of intracellular CD11b and BDNF and the secretion level of TNF‐αin the supernatant were measured .Finally adding exogenous recombinant BDNF into cultured BV 2 microglia ,intracellular changes of CD11b and supernatant TNF‐αlevels were detected .Results After adding ATP for cultivating BV2 microglia ,intracellular CD11b and BDNF expression levels and supernatant TNF‐αlevel were increased with a dose‐and time‐dependent manner in some ranges . After adding TrkB/Fc ,the levels of intracellular CD11b and BDNF expression and supernatant TNF‐αlevel were decreased with a dose‐and time‐dependent manner in some range .CD11b and BDNF expression levels was decreased in a dose‐and time‐dependent manner .Adding exogenous BDNF ,the levels of intracellular CD11b and BDNF expression and supernatant TNF‐α level were in‐creased again .Conclusion Intracellular BDNF expression is increased when BV2 microglia is activated and replenishing exogenous BDNF can activate microglia .Therefore BDNF may play an important role in the microglia activation process .