【摘要】 目的:探讨不可分型流感嗜血杆菌(NTHi)致肺泡上皮细胞炎症反应的分子机制。方法:A549肺泡上皮细胞株与NTHi(感染复数:10)共孵育15 min、30 min后收集细胞,用Western blotting检测p38丝裂原活化蛋白激酶(p38 MAPK)的磷酸化;4 h后用流式细胞仪检测胞内NF-κB p65亚单位的表达。预先用p38 MAPK抑制剂(SB203580)和NF-κB抑制剂(PDTC)与A549细胞共孵育1 h,然后加入NTHi,24 h后收集上清,以酶联免疫吸附法检测白介素8(IL-8)的水平。结果:NTHi能迅速地诱导p38 MAPK通路的磷酸化。NTHi刺激4 h后A549细胞胞内NF-κB p65的表达较与未加细菌组明显增加(P<0.05)。NTHi刺激A549细胞24 h后上清中的IL-8较未加细菌组显著增加,差异显著(P<0.05)。与细菌攻击组比较,阻断p38 MAPK或NF-κB通路,能显著地降低A549细胞生成IL-8(P<0.05)。结论:NTHi以p38 MAPK和NF-κB依赖的方式诱导肺泡上皮细胞的炎症反应。更多还原

【Abstract】 AIM: To investigate the key molecular mechanism of inflammatory response in alveolar epithelial cells induced by nontypeable haemophilus influenzae(NTHi).METHODS: A549 cells were co-cultured with NTHi(multiplicity of infection,MOI: 10) and harvested 15 min and 30 min after stimulation.The phosphorylation of p38 mitogen activated protein kinase(p38 MAPK) in A549 cells was detected by Western blotting.The intracellular expression of nuclear factor-κB(NF-κB) p65 was examined by flow cytometry 4 h after stimulation.A549 cells were preincubated with p38 inhibitor(SB203580) or NF-κB inhibitor(PDTC) for 1 h and then stimulated with NTHi for 24 h.The level of interleukin 8(IL-8) in the supernatants was determined by enzyme-linked immunosorbent assay(ELISA).RESULTS: The phosphorylation of p38 MAPK was rapidly induced by NTHi stimulation.The expression of NF-κB p65 in A549 cells after NTHi stimulation was significantly up-regulated compared with control group(P<0.05).The level of IL-8 in the supernatants was increased 24 h after bacterial stimulation compared with control group(P<0.05).Blockage of p38 MAPK or NF-κB remarkably decreased IL-8 secretion in A549 cells(P<0.05).CONCLUSION: NTHi induces inflammatory response in alveolar epithelial cells in a p38 MAPK and NF-κB dependent manner.更多还原