TY - JOUR
T1 - Tyrosine phosphorylation of vascular endothelial cadherin and the regulation of microvascular permeability
AU - Nwariaku, Fiemu E.
AU - Liu, Zijuan
AU - Zhu, Xudong
AU - Turnage, Richard H.
AU - Sarosi, George A.
AU - Terada, Lance S.
N1 - Funding Information:
Supported in part by a Department of Veterans Affairs Merit Review Entry Program grant and Veterans Integrated Service Network 17 research grant.
PY - 2002/8
Y1 - 2002/8
N2 - Background. Adherens junctions (AJ), by their association with the endothelial cytoskleton, maintain microvascular barrier integrity. Phosphorylation states of AJ proteins, such as vascular endothelial (VE) cadherin, can potentially alter the interactions between component AJ proteins. Furthermore, AJ protein phosphorylation is susceptible to regulation by inflammatory mediators. We previously demonstrated the importance of VE cadherin in tumor necrosis factor (TNF)-mediated endothelial permeability. We now postulate that TNF-induced endothelial permeability is associated with tyrosine phosphorylation of VE cadherin. Methods. Confluent monolayers of human umbilical vein endothelial cells were exposed to saline solution, TNF-α (100 U/mL) or TNF and the Src-tyrosine kinase inhibitor, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine. Permeability was assessed by fluorescein isothiocyanate-dextran flux. VE-cadherin phosphorylation was determined by immunoprecipitation and immunoblotting with antiphosphotyrosine antibody. Data are expressed as mean ± SEM and analyzed by analysis of variance. Results. TNF-α-induced tyrosine phosphorylation of VE cadherin and increased intercellular gap formation. These changes were associated with increased endothdial-cell monolayer permeability, all of which were prevented by 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine. Exposure to an inactive tyrphostin, AG9 (negative control), did not prevent TNF-induced endothelial permeability. Conclusions. We conclude that tyrosine phosphorylation of VE cadherin is an important regulatory pathway associated with TNF-induced endothelial barrier dysfunction. Modulating AJ protein phosphorylation may provide targets for therapy during inflammation.
AB - Background. Adherens junctions (AJ), by their association with the endothelial cytoskleton, maintain microvascular barrier integrity. Phosphorylation states of AJ proteins, such as vascular endothelial (VE) cadherin, can potentially alter the interactions between component AJ proteins. Furthermore, AJ protein phosphorylation is susceptible to regulation by inflammatory mediators. We previously demonstrated the importance of VE cadherin in tumor necrosis factor (TNF)-mediated endothelial permeability. We now postulate that TNF-induced endothelial permeability is associated with tyrosine phosphorylation of VE cadherin. Methods. Confluent monolayers of human umbilical vein endothelial cells were exposed to saline solution, TNF-α (100 U/mL) or TNF and the Src-tyrosine kinase inhibitor, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine. Permeability was assessed by fluorescein isothiocyanate-dextran flux. VE-cadherin phosphorylation was determined by immunoprecipitation and immunoblotting with antiphosphotyrosine antibody. Data are expressed as mean ± SEM and analyzed by analysis of variance. Results. TNF-α-induced tyrosine phosphorylation of VE cadherin and increased intercellular gap formation. These changes were associated with increased endothdial-cell monolayer permeability, all of which were prevented by 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine. Exposure to an inactive tyrphostin, AG9 (negative control), did not prevent TNF-induced endothelial permeability. Conclusions. We conclude that tyrosine phosphorylation of VE cadherin is an important regulatory pathway associated with TNF-induced endothelial barrier dysfunction. Modulating AJ protein phosphorylation may provide targets for therapy during inflammation.
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U2 - 10.1067/msy.2002.125305
DO - 10.1067/msy.2002.125305
M3 - Article
C2 - 12219009
AN - SCOPUS:0036674284
SN - 0039-6060
VL - 132
SP - 180
EP - 185
JO - Surgery
JF - Surgery
IS - 2
ER -