百草枯对人肺泡上皮屏障的影响及机制研究  

Impacts of paraquat on human alveolar epithelial barrier and the exploration of the underlying mechanism

作　　者：刘艳琴[1] 史红阳[1] 邓文静[1] 李芳侠[1] Liu Yanqin;Shi Hongyang;Deng Wenjing;Li Fangxia(Department of Respiration and Critical Care Medicine ,the Second Affiliated Hospital of Xi'an Jiaotong University ,Xi'an 710004,China)

机构地区：[1]西安交通大学第二附属医院呼吸与危重症医学科,710004

出　　处：《国际呼吸杂志》2018年第23期1787-1791,共5页International Journal of Respiration

摘　　要：目的用体外人肺泡上皮屏障模型,研究百草枯对人肺泡上皮屏障的影响,并初步探讨其潜在的机制。方法通过噻唑蓝(MTT)试验和细胞计数研究百草枯对H441细胞增殖的影响,使用跨上皮电阻率(TERR)测量和荧光素标记的葡聚糖(FITC‐Dextran)通透性试验研究上皮屏障的通透性,使用蛋白质印迹法(WB)研究百草枯对H441细胞中钙黏附连接蛋白E((E‐cadherin)和紧密连接蛋白‐1(ZO‐1)表达的影响。结果处理24h后,从200μM浓度开始,百草枯可显著抑制细胞的增殖(P<0.05)。H441单层细胞可形成上皮屏障,表现为随着培养时间的延长,TERR值逐渐升高(P<0.05),而FITC‐Dextran通透性逐渐降低(P<0.05),且从第9天开始趋于平稳(P>0.05)。待H441单层细胞上皮屏障完全建立后,百草枯可显著破坏H411单层细胞的上皮屏障,表现为TERR值的降低(P<0.05)和FITC‐Dextran通透性的升高(P<0.05)。百草枯处理24h后,细胞中E‐cadherin和ZO‐1的表达均显著降低(P<0.05)。结论百草枯通过抑制E‐cadherin和ZO‐1的表达,破坏体外人肺泡上皮屏障模型H441单层细胞的上皮屏障,为百草枯引起急性肺损伤的机制提供了一定的理论基础。Objective To investigate the impacts of paraquat on human alveolar epithelial barrier using an in vitro human alveolar epithelial barrier model and to further explore its underlying mechanisms .Methods The impacts of paraquat on the proliferation of H441 cells were determined by methyl thiazolyl tetrazolium ( MTT ) assay and cell counting assays .The transepithelial resistance rate ( TERR) measurement and the FITC‐Dextran permeability assay were used to evaluate the permeability of epithelial barriers .The influence of paraquat on the expression of adherin junction protein ( E‐cadherin) and tight junction protein zonula occludens‐1 ( ZO‐1 ) in H441 cells was determined by western‐blot (WB) .Results After 24 h treatment ,paraquat significantly inhibited cell proliferation ( P < 0 .05) from a concentration of 200 μM .Epithelial barrier was formed in H441 monolayers ,because TERR value increased ( P < 0 .05 ) while FITC‐Dextran permeability decreased ( P < 0 .05 ) gradually with the prolongation of culture time ,and from the 9th day on ,TERR value and FITC‐Dextran permeability stayed unchanged ( P > 0 .05) .After the formation of epithelial barrier in H441 monolayers ,paraquat treatment significantly disrupted the epithelial barrier ,which was evidenced in the decrease of TERR value ( P < 0 .05) and the increase of FITC‐Dextran permeability ( P < 0 .05) .24 h paraquat treatment significantly down‐regulated the expression of E‐cadherin and ZO‐1 ( P < 0 .05) .Conclusions Paraquat disrupted the epithelial barrier of human alveolar epithelial barrier model ( H441 monolayer) in vitro ,and the downregulation of E‐cadherin and ZO‐1 was the underlying mechanism ,providing a theoretical basis for the mechanisms of acute lung injury induced by paraquat .

关 键 词：百草枯 急性肺损伤 肺泡上皮屏障 钙黏附蛋白E 紧密连接蛋白‐1 

分 类 号：R595.4[医药卫生—内科学]