Role of protein tyrosine phosphorylation in acetaldehyde-induced disruption of epithelial tight junctions.
Am J Physiol Gastrointest Liver Physiol
; 280(6): G1280-8, 2001 Jun.
Article
em En
| MEDLINE
| ID: mdl-11352822
ABSTRACT
Acetaldehyde-induced cytotoxicity is an important factor in pathogenesis of alcohol-related diseases; however, the mechanism of this toxicity is unknown. We recently showed that acetaldehyde increases epithelial paracellular permeability. We asked whether protein tyrosine phosphorylation via modulation of tyrosine kinases and/or PTPases is a mechanism involved in acetaldehyde-induced disruption of the tight junctions in the Caco-2 cell monolayer. Immunofluorescence localization of occludin and ZO-1 showed disruption of the tight junctions in acetaldehyde-treated cell monolayer. Administration of genistein prevented acetaldehyde-induced permeability. Acetaldehyde increased tyrosine phosphorylation of three clusters of proteins with molecular masses of 30-50, 60-90, and 110-150 kDa; three of these proteins were ZO-1, E-cadherin, and beta-catenin. Acetaldehyde reduced PTPase activity in plasma membrane and soluble fractions, whereas tyrosine kinase activity remained unaffected. Treatment with acetaldehyde resulted in a 97% loss of protein tyrosine phosphatase (PTP)1B activity and a partial reduction of PTP1C and PTP1D activities. These results strongly suggest that acetaldehyde inhibits PTPases to increase protein tyrosine phosphorylation, which may result in disruption of the tight junctions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tirosina
/
Transativadores
/
Junções Íntimas
/
Epitélio
/
Acetaldeído
Limite:
Humans
Idioma:
En
Revista:
Am J Physiol Gastrointest Liver Physiol
Assunto da revista:
FISIOLOGIA
/
GASTROENTEROLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos