论文部分内容阅读
目的研究肺炎链球菌表面暴露的毒性表面蛋白A(PspA)促进CXCL8分泌的可能机制。方法使用炎症相关的信号分子NF-κB、p38MARK、ERK、JNK的抑制剂预处理人嗜中性粒细胞后,观察PspA对CXCL8分泌作用的影响。从受PspA刺激的人嗜中性粒细胞中分别提取细胞总蛋白和细胞核提取物,用ELISA法测定p38MAPK蛋白的活力和NF-κB的浓度的改变,并且采用Western blot方法进一步验证PspA对p38MAPK和IkB-α蛋白磷酸化水平的影响。结果使用NF-κB,p38MARK的抑制剂预处理人嗜中性粒细胞后,可以扭转PspA促中性粒细胞分泌CXCL8的现象;而ERK,JNK的抑制剂无此效果。另一方面,PspA可以上调中性粒细胞中的P38 MAPK蛋白的含量和NF-κB的浓度,也可以提高p38MAPK和NF-κB通路抑制蛋白IkB-α的磷酸化水平。结论肺炎链球菌PspA诱导人体中性粒细胞释放CXCL8受p38蛋白和NF-κB途径的调控。
Objective To investigate the possible mechanism of CXCL8 secretion induced by Streptococcus pneumoniae surface exposed toxic surface protein A (PspA). Methods The effect of PspA on CXCL8 secretion was observed after pretreatment of human neutrophils with inhibitors of NF-κB, p38MARK, ERK and JNK. Cell total protein and nuclear extracts were extracted from PspA-stimulated human neutrophils, respectively, and the changes of p38MAPK protein activity and NF-κB concentration were determined by ELISA. Western blot was used to further verify the effect of PspA on p38MAPK and Effect of IkB-α Protein Phosphorylation. Results The pretreatment of human neutrophils with inhibitors of NF-κB and p38MARK reversed the phenomenon that CXCL8 was secreted by PspA-induced neutrophils, whereas inhibitors of ERK and JNK did not. On the other hand, PspA up-regulated the content of P38 MAPK and the concentration of NF-κB in neutrophils, and also increased the phosphorylation levels of p38MAPK and NF-κB pathway inhibitor IkB-α. Conclusion Streptococcus pneumoniae PspA induces the release of CXCL8 from human neutrophils by the p38 protein and NF-κB pathway.