title: Altered distribution of tight junction proteins after intestinal ischaemia/reperfusion injury in rats.
abstract: Tight junction (TJ) disruptions have been demonstrated both in vitro and more recently in vivo in infection. However, the molecular basis for changes of TJ during ischaemia-reperfusion (I/R) injury is poorly understood. In the present study, intestinal damage was induced by I/R in an animal model. As assessed by TUNEL and propidium iodide uptake, we showed that I/R injury induced apoptosis as well as necrosis in rat colon, and the frequency of apoptotic and necrotic cells reached the maximum at 5 hrs of reperfusion. Immunofluorescence microscopy revealed that claudins 1, 3 and 5 are strongly expressed in the surface epithelial cells of the colon; however, labelling of all three proteins was present diffusely within cells and no longer focused at the lateral cell boundaries after I/R. Using Western blot analysis, we found that distribution of TJ proteins in membrane microdomains of TJ was markedly affected in I/R injury rats. Occludin, ZO-1, claudin-1 and claudin-3 were completely displaced from TX-100 insoluble fractions to TX-100 soluble fractions, and claudin-5 was partly displaced. The distribution of lipid raft marker protein caveolin-1 was also changed after I/R. I/R injury results in the disruption of TJs, which characterized by relocalization of the claudins 1, 3 and 5 and an increase in intestinal permeability using molecular tracer measurement. I/R injury altered distribution of TJ proteins in vivo that was associated with functional TJ deficiencies.
authors.affiliation: Institute of General Surgery, Jinling Hospital, Nanjing, China. liqiurong@yahoo.com
authors.forename: Qiurong
authors.initials: Q
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Chenyang
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Liu
authors.forename: Linlin
authors.initials: L
authors.lastname: Qu
authors.forename: Lili
authors.initials: L
authors.lastname: Gu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Jieshou
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D062445:Claudin-1; D062465:Claudin-3; D062507:Claudin-5; D057167:Claudins / Q000096:biosynthesis; D003902:Detergents / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000473:pathology*; D008297:Male; D021962:Membrane Microdomains / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis; D018613:Microscopy, Confocal / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology*; D019108:Tight Junctions / Q000473:pathology*
chemical_list: D062445:Claudin-1; D062465:Claudin-3; D062507:Claudin-5; D057167:Claudins; C568114:Cldn1 protein, rat; C568124:Cldn3 protein, rat; C491510:Cldn5 protein, rat; D003902:Detergents; D008565:Membrane Proteins; C551282:polyethylene glycol monooctylphenyl ether; D011092:Polyethylene Glycols