TNF-α影响肠黏膜上皮细胞间紧密连接蛋白的表达  

Effect of TNF-a on tight junctions between the epithelial cells of intestinal mucosal barrier

作　　者：宋红丽[1] 吕飒[1] 马力[1] 李颖[1] 刘沛[1] 

机构地区：[1]中国医科大学附属第二医院感染科,辽宁省沈阳市110004

出　　处：《世界华人消化杂志》2004年第6期1303-1306,共4页World Chinese Journal of Digestology

基　　金：卫生部临床重点项目;No.97100252~~

摘　　要：目的:探讨肿瘤坏死因子(TNF-α)对肠黏膜上皮细胞间紧密连接的影响. 方法:应用免疫荧光方法检测在肿瘤坏死因子(TNF-α)0, 50,100和200μg/L作用下,与结肠癌上皮细胞株(CaCo- 2细胞株)共同培养24 h,以及用TNF-α100 μg/L与CaCo- 2细胞共同培养0,4,8和24 h,观察TNF一-α对紧密连接蛋白(zonula occluden 1,ZO-1)表达的影响.并应用半定量RT-PCR方法检测TNF-α用上述相应的时间和浓度作用后对肠黏膜上皮细胞ZO-1 mRNA表达的影响. 结果:用TNF-α100和200 μg/L作用24 h后ZO-1的免疫荧光明显减少,并呈剂量依赖性;用TNF-α100 μg/L作用24 h时ZO-1免疫荧光明显减少,并呈时间依赖性.应用半定量RT-PCR的方法检测结果:TNF-α作用24 h时, ZO-1 mRNA从TNF-α0μg/L的1.1926降至100μg/L的0.7834和200 μg/L的0.7081;TNF-α100μg/L作用4 h, ZO-1mRNA为(95.5±5.5%);8 h为(82.0±5.4%);24 h 降至最低为(67.7±5.7%),与对照组相比P<0.01. 结论:TNF-α是通过抑制肠上皮细胞间紧密连接蛋白ZO-1 表达引起肠黏膜上皮细胞间紧密连接破坏.并且是通过抑制ZO-1 mRNA引起肠上皮细胞ZO-1蛋白表达降低.AIM: To investigate the effect of TNF-α on tight junctions between the epithelial cells of the intestinal mucosal barrier. METHODS: Colon cancer cell line (CaCo-2) was cultured. The localizations of zonula occluden-1 (ZO-1) in CaCo-2 epithelial cells were detected by immunofluorescence after exposure to TNFα (0, 50, 100 and 200 μg/L) for 24 h and the TNF-α treatment with 100 μg/L for 0, 4, 8 and 24 h. The expression level of ZO-1 was analyzed by semi-quantitative reverse transcriptase-PCR after exposure to TNFα with the above time and concentration. RESULTS: Different expression levels of ZO-1 depended on different time and concentration of TNF-a treated on CaCo-2 epithelial cells. The integrity of tight junctions was disrupted and the expression level of ZO-1 decreased after treatment with TNF-α. The intensity of the immunof-luorescent signal was less intensive after exposure to TNFα 100 and 200 μg/L than that to 0 and 50 μg/L. The intensity of the immunofluorescent signal was less intensive after exposure to TNFa 100 μg/L for 24 hours than those for 0 h, 4 h and 8 h. The RT-PCR results showed that after CaCo-2 cells were treated for 24h with the indicated concentrations (0, 50, 100 and 200 μg/L) of TNF-a and the TNF-α treatment with 100 μg/L for 0 h, 4 h, 8 h and 24 h, the expression levels of ZO-1 mRNA in CaCo-2 cells were decreased by TNF-a with 100 μg/L for 24 h, as compared with control (P <0.01). CONCLUSION: Tight junctions between the epithelial cells of the intestinal mucosal barrier can be destroyed by TNF-α, and decreased expression level of ZO-1 induced by TNF-α is one of the most important molecular mechanisms.

关 键 词：TNF-Α 肠黏膜 上皮细胞 紧密连接蛋白 基因表达 肝炎 

分 类 号：R574[医药卫生—消化系统]