摘要
目的:研究肠上皮细胞(Caco-2)在侵袭性大肠杆菌(enteroinvasive Escherichia coli,EIEC)感染后,紧密连接(TJ)相关蛋白表达的改变及乳酸菌对Caco-2细胞的保护作用机制.方法:将Caco-2感染模型分为正常组、感染组、乳酸菌处理组和庆大霉素处理组.采用免疫金标记及电镜观察上皮细胞间TJ的位置和超微结构.免疫荧光观察TJ相关蛋白(Claudin-1,Occludin,JAM-1,ZO-1)及F-actin的表达分布和超微结构变化.结果:紧密连接结构位于相邻上皮细胞间的顶端,间隙大小约25-38nm.EIEC感染后,免疫胶体金定位不清,细胞骨架F-actin遭到破坏,相邻Caco-2细胞间TJ结构遭到破坏,TJ相关蛋白(Claudin-1蛋白,Occludin蛋白,JAM-1蛋白,ZO-1蛋白)的表达亦减少,而乳酸菌处理后F-actin的表达明显增多,可减轻EIEC引起的TJ结构受损,TJ相关蛋白的表达增多.结论:EIEC感染导致Caco-2细胞细胞骨架F-actin、TJ相关蛋白的表达和分布发生改变.乳酸菌可以明显抑制EIEC引起的单层细胞TJ结构和相关蛋白的破坏,并改善细胞骨架的分布表达.
AIM: To investigate the alteration of intestinal epithelial tight junction proteins after infection with enteroinvasive Escherichia coli and to study mechanism underlying protective effect of Lactobacillus plantarun on Caco-2 cells. METHODS: Caco-2 models were established and divided into normal group, infection group, Lactobacillus treatment group and gentamicin treatment group. Ultrastructure of tight junction structure was observed using immuno-gold labeling. The distribution and structure of tight junction proteins, such as Claudin-1, Occludin, ZO-1, JAM-1 as well as F-actin were examined using immunofluorescence assay.RESULTS: The tight junction structure was at the top of intestine epithelial cells. After infection with EIEC, the structure of tight junction was destroyed and the expression of F-actin and tight junction proteins (such as Claudin-1, Occludin, JAM-1, ZO-1) were diminished. But Lactobacillus plantarun prevented induced by EIEC. damage CONCLUSION: The Lactobacillus plantarun exerts a protective effect against the damage to the F-actin and distribution of TJ proteins promoted by enteroinvasive Escherichia coil infection.
出处
《世界华人消化杂志》
CAS
北大核心
2008年第30期3394-3399,共6页
World Chinese Journal of Digestology
基金
国家自然科学基金资助项目
No.30471687~~