Linked Life Data

11949786

Source:http://linkedlifedata.com/resource/pubmed/id/11949786

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-4-12
pubmed:abstractText
In this study, we report on the apparent effect of increased tyrosine phosphorylation events on the assembly and integrity of adherens junctions (AJs) and on paracellular permeability in Caco-2 cells. Cell monolayers were incubated with the phosphotyrosine phosphatase inhibitor vanadate/H2O2. Addition of this compound to monolayer resulted in disruption of the AJs, as revealed by electron microscopy and by a loss of membrane association of the AJ-associated protein uvomorulin/E-cadherin (U/E-c). However, tight junctions (TJs) were unaltered, as determined by measuring the transepithelial resistance (Rt), by ruthenium red labeling, as seen by transmission electron microscopy, and the distribution of TJ strands as seen in freeze-fracture replicas and by hyperphosphorylation of triton-insoluble occludin. Also examination of vanadate/H2O2 treated cells indicated a specific increase in AJ-associated phosphotyrosine residues as evaluated by immunofluorescence microscopy, but no modification of F-actin distribution, as revealed by confocal laser scanning microscopy analysis. To verify that modulation of AJs was indeed related to tyrosine phosphorylation, we tested a range of distinct protein kinase inhibitors. Of the three inhibitors tested (tyrphostin 25, genistein and staurosporine), tyrphostin 25 completely blocked the effects of vanadate/ H2O2 on assembly and integrity of AJs, redistribution of U/E-c and phosphotyrosine labeling. Our results indicate that, after addition of vanadate/H2O2 to Caco-2 monolayers, specific tyrosine phosphorylation of proteins cause disruption of AJs, but no modifications of the TJs' structure and functionality. These observations suggest that, in contrast to what happens with epithelial cells, TJs and AJs of Caco-2 cells are regulated by independent mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0040-8166
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
500-13
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Evidence that increased tyrosine phosphorylation causes disassembly of adherens junctions but does not perturb paracellular permeability in Caco-2 cells.
pubmed:affiliation
Divisão de Biologia Celular, Coordenação de Pesquisa, Instituto Nacional de Câncer, Rio de Janeiro, Brasil. biocel@inca.org.br
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't