脂多糖诱导肺泡上皮细胞炎性损伤及损伤机制  

A study on the inflammatory responses of alveolar epithelial cells induced by lipopolysaccharide andthe underlying mechanisms

作　　者：刘瑞吉 徐淑凤 陈良安[2] 王平[2] 梁志新[2] 孙继萍[2] 赵晓巍[2] 李爱民[2] 

机构地区：[1]第一医院呼吸科,秦皇岛市066000 [2]解放军总医院呼吸科

出　　处：《中华结核和呼吸杂志》2011年第5期367-370,共4页Chinese Journal of Tuberculosis and Respiratory Diseases

摘　　要：目的探讨细菌脂多糖（LPS）诱导的肺泡上皮细胞（AEC）炎症反应及可能的反应机制。方法将人肺腺癌细胞系A549细胞株分为2组：对照组和LPS干预组，分别培养并于0．5h、2h、6h和12h时留取标本进行相关细胞因子检测。酶联免疫吸附法（ELISA）检测细胞间黏附分子-1（ICAM-1），放射免疫法检Nile瘤坏死因子-α（TNF-α）和白细胞介素-8（IL-8）的水平。实时荧光定量PCR检测TLR-4mRNA的表达；蛋白质免疫印迹（Westernblot）法检测核转录因子．KB（NF-KB）抑制蛋白IKB-α和NF-KBp65蛋白水平，观察NF-KB的活性变化。结果与对照组比较，LPS使AECs分泌的ICAM-1，TNF-α和IL-8于2h、6h和12h均升高，ICAM．1，TNF-α于2h、IL-8于12h达分泌高峰；作用2h后TLR-4mRNA表达明显升高并达到峰值（27．884±13．31），6h后（19．824±15．58）仍高于对照组（1．004-0．00），组间比较差异有统计学意义（P〈0．05），12h时（12．864±11．45）组间比较差异无统计学意义（P〉0．05）；NF-KB活性于刺激后0．5h、2h、6h和12h均明显增加，表现为抑制蛋白IKB-α迅速降解，NF．KBp65蛋白同步释出并转入细胞核内。结论LPS能够激活肺泡上皮细胞使其释放大量炎性因子，这一过程可能是通过激活TLR-4并进而激活NF．KB而诱导了AECs的炎性损伤。Objective Lipopolysaccharide （LPS） can activate alveolar epithelial cells （AECs） and induce inflammatory injury. Toll-like receptor-4 （TLR-4） is integrally involved in LPS signaling and plays a requisite role in the activation of NF-KB. NF-KB is a key intercellular signaling event that mediates cell inflammatory responses. The aim of the study was to investigate in an in vitro model the inflammatory responses of AECs induced by LPS and the underlying mechanisms. Methods The study was performed on A549 cells （Human lung adenocarcinoma cell line）. A549 cells were divided into 2 groups： a control group and a LPS stimulation group. Proinflammatory cytokines ICAM-I, TNF-ct and IL-8 were detected by ELISA or radioimmunological methods. The expression of TLR-4 mRNA was detected by real time PCR. The activation of NF-KB was detected by Western blot （ proteins of I-KBct and NF-KB p65 ）. Results Compared with the control group, the ICAM-1 and TNF-oL levels of the LPS-stimulated group were significantly higher, peaked after 2 h, and then gradually decreased at 6 and 12 h. IL-8 was also significantly increased after 2 h, which continued up to 12 h. The expression of TLR-4 mRNA in the LPS group was significantly higher, peaked after 2 h and gradually decreased at 6 and 12 h. NF-KB was activated after O. 5, 2, 6 and 12 h, indicated by the significant degradation of IKB-ct and the significant release of NF-KB P65 and its subsequent translocation into the nucleus approximately synchronized. Conclusion The results demonstrate that LPS induced inflammatory injury in AECs via activating TLR-4 and subsequently NF-KB.

关 键 词：脂多糖类 TOLL样受体4 NF-KB 肺泡上皮细胞 

分 类 号：R363[医药卫生—病理学]