肠分化细胞黏蛋白O-型糖链合成抑制导致MUC2表达减低以及对细菌侵袭易感  

Inhibition of O-glycan chains synthesis in intestinal differentiated epithelial cells induces lower MUC2 expression and susceptibility to bacterial invasion

作　　者：叶钧[1] 宋丽丽[1] 刘韵[1] 田音[1] 潘琼[1] 彭志红[1] 汪荣泉[1] 

机构地区：[1]第三军医大学西南医院全军消化病研究所,重庆400038

出　　处：《第三军医大学学报》2013年第19期2056-2059,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金面上项目(81170340)~~

摘　　要：目的探讨O-型糖链合成的抑制对肠分化细胞内细菌侵袭数量和细胞内MUC2表达水平的影响。方法对肠分化细胞(HT-29-Gal)用O-型糖链抑制剂(benzyl-N-acetyl-α-D-galactosaminide,benzyl-α-GalNAc)处理,采用Real-time PCR和Western blot检测MUC2 mRNA和蛋白的表达情况。并将HT-29-Gal细胞及benzyl-α-GalNAc处理的HT-29-Gal细胞分别与肠致病性大肠杆菌(enteropathogenic E.coli,EPEC)和肠出血性大肠杆菌(EHEC O157∶H7)37℃孵育2 h,再加入100μg/mL的庆大霉素,杀灭细胞外及粘附于细胞表面的细菌。最后采用系列稀释克隆计数法观察benzyl-α-GalNAc处理的HT-29-Gal细胞对细菌侵袭的影响。结果 Real-time PCR和Western blot检测发现经benzyl-α-GalNAc处理的HT-29-Gal细胞MUC2的mRNA和蛋白表达水平明显降低(P<0.05)。侵袭入benzyl-α-GalNAc处理的HT-29-Gal细胞的EPEC和EHEC O157∶H7的数量较对照细胞显著增加(P<0.05)。结论抑制HT-29-Gal细胞黏蛋白O-型糖链的合成导致侵袭入细胞内细菌数量增加和MUC2的表达降低。Objective To determine the effect of inhibiting O-glycan chains synthesis in intestinal differentiated epithelial cells on the bacteria invasion into the cells and MUC2 expression. Methods The intestinal differentiated cell line HT-29-Gal was treated with O-glycan chains synthesis inhibitor, benzyl-N- acetyl-oL-D-galactosaminide （benzyl-oL-GalNAc）. The expression of MUC2 at mRNA and protein levels was detected by real-time PCR and Western blotting. The HT-29-Gal cells treated with or without benzyl-α-GalNAc were co-cultured with enteropathogenic E. coli （EPEC）and enterohemorrhage E. coli （EHEC O157：H7 ）for 2 h, then the gentamicin （ 100 μg/mL） was added in the culture medium for 2 h to exclude extracellular and cellular surface-adherent bacteria after 3 times of washing with PBS. Finally, serial dilution cloning counting was used to observe the numbers of invaded bacteria into the HT-29-Gal cells treated with or without benzyl-α-GalNAc. Results Real-time PCR and Western blotting indicated that the mRNA and protein Levels of MUC2 were significantly lower in HT-29-Gal cells treated with the benzyl-α-GalNAc than the untreated HT-29-Gal cells （P 〈 0.05 ）. The numbers of EPEC and EHEC O157：H7 invaded into the HT-29-Gal cells exposed to benzyl-α- GalNAe were significantly larger than those untreated （ P 〈 0.05 ）. Conclusion Inhibition of O-glyean chains synthesis in HT-29-Gal cells leads more bacteria to invade into the cells and lower expression of MUC2 at both mRNA and protein levels.

关 键 词：O-型糖链 benzyl-α-GalNAc HT-29-Gal细胞 

分 类 号：R322.45[医药卫生—人体解剖和组织胚胎学] R392.32[医药卫生—基础医学]