title: Enteropathogenic Escherichia coli changes distribution of occludin and ZO-1 in tight junction membrane microdomains in vivo.
abstract: Diarrhea is a disease caused by enteropathogenic Escherichia coli (EPEC) infection, which caused the deaths of several hundred thousand children each year. However, the molecular mechanisms underlying EPEC infection in vivo are not fully understood. In the present study, we used the C57BL/6J mouse as an in vivo model of EPEC infection and investigated the effect of EPEC on tight junction (TJ) structure and barrier function. TJ ultrastructure was studied by transmission electron microscopy and a small molecule tracer biotin was used to examine the paracellular permeability of the colon. The distribution of TJ proteins occludin and ZO-1 in the epithelium was investigated by immunofluorescence microscopy. Our results demonstrated that TJ structure was disrupted following EPEC infection. And the morphological changes of TJ were accompanied by increased paracellular permeability which led to impairment of TJ barrier function. Immunofluorescency analysis revealed that occludin and ZO-1 were translocated from villous membrane to the cytoplasm in intestinal epithelial cells during EPEC invasion. Moreover, wild-type EPEC and the mutant EPEC strain, DeltaespF, had similar effects on barrier function and TJ protein localization at 5 days postinfection. Our findings demonstrate that EPEC infection in vivo led to disruption of tight junction barrier function. These results may provide insights into the molecular mechanism of the pathogenesis of EPEC infection.
authors.affiliation: School of Medicine, Nanjing University, Nanjing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Qiurong
authors.initials: Q
authors.lastname: Li
authors.forename: Chenyang
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Liu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Jieshou
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D001710:Biotin / Q000378:metabolism; D003106:Colon / Q000382:microbiology / Q000473:pathology* / Q000648:ultrastructure; D054308:Enteropathogenic Escherichia coli / Q000472:pathogenicity*; D007413:Intestinal Mucosa / Q000382:microbiology / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D021962:Membrane Microdomains / Q000737:chemistry*; D008565:Membrane Proteins / Q000032:analysis*; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D062793:Occludin; D010539:Permeability; D010750:Phosphoproteins / Q000032:analysis*; D013194:Staining and Labeling / Q000379:methods; D019108:Tight Junctions / Q000737:chemistry*; D062826:Zonula Occludens-1 Protein
chemical_list: D008565:Membrane Proteins; D062793:Occludin; C568986:Ocln protein, mouse; D010750:Phosphoproteins; C569043:Tjp1 protein, mouse; D062826:Zonula Occludens-1 Protein; D001710:Biotin