【摘要】 目的探讨大肠杆菌(E.coli)感染与人巨噬细胞系U937细胞凋亡的关系及核转录因子(nuclear factorkappa B,NF-κB)表达的变化。方法以Annexin V FITC/PI双染流式细胞仪检测及Hoechst 33258荧光染色观察为指标,研究E.coli感染对人巨噬细胞系U937细胞凋亡的诱导作用;用Western blot方法检测NF-ΚB的表达。结果Ho-echst 33258荧光染色结果表明当细胞与细菌浓度比较低时(1:10)可引起部分细胞凋亡,Annexin V FITC/PI双染流式细胞仪结果表明,当细胞与细菌浓度比为1:20,1:50及1:100时,细胞凋亡率与对照组相比明显增高,有显著性差异(P<0.001)。NF-κB的表达随着E.coli浓度的增加而逐渐降低。结论E.coli以剂量依赖的方式诱导U937细胞凋亡,在此过程中NF-κB的表达逐渐降低。更多还原

【Abstract】 Objective To study the relationship of E.coli to human monocytic U937 cell apoptosis and expression of nuclear factor kappa B(NF-κB).Methods The U937 apoptosis induced by E.coli was detected with Annexin V FITC/PI assay and Hoechst 33258 fluorochrome staining.Western blot was used to detect the expression of NF-κB.Results Annexin V FITC/PI assay and Hoechst 33258 fluorochrome staining found the apoptotic cells at multiplicity of infections(MOI) of 10:1 after E.coli had infected U937,and the percentage of apoptotic cells increased with the increase in the concentration of E.coli.The infection groups at MOI of 20:1,50:1 and 100:1 induced significantly more U937 apoptosis than in the control group(P<0.001).The expression of NF-κB was reduced.Conclusion E.coli can induce apoptosis in human U937 cells with a down-regulated expression of NF-κB,and this might be related to the induction of apoptosis of the infected cells.更多还原