Tyrosine phosphatase beta regulates angiopoietin-Tie2 signaling in human endothelial cells.
Angiogenesis
; 12(1): 25-33, 2009.
Article
em En
| MEDLINE
| ID: mdl-19116766
ABSTRACT
OBJECTIVES:
The endothelial cell (EC)-selective receptor tyrosine kinase, Tie2, and its ligands angiopoietin Ang-1 and Ang-2, are essential for blood vessel maintenance and repair. Ang-1 is an agonist of Tie2 receptor activation, whereas Ang-2 is a context-dependent antagonist/agonist. Therefore, we investigated the role of the EC-selective phosphatase, human protein tyrosine phosphatase beta (HPTPbeta), in regulating Tie2 activity. METHODS ANDRESULTS:
siRNA silencing of HPTPbeta enhanced Ang-1 and Ang-2-induced Tie2 phosphorylation at 10 min (2.5-fold, P < 0.001; and 1.8-fold, P < 0.05, respectively). The cell survival response to Ang-1, but not Ang-2, was enhanced by HPTPbeta silencing as measured by flow cytometry (0.85-fold to 0.66-fold, P < 0.05) and ELISA (0.88-fold to 0.53-fold, P < 0.01). Hypoxia, which upregulated HPTPbeta expression in endothelial cells, impaired Ang-1-induced Tie2 phosphorylation.CONCLUSIONS:
These results reveal a novel role for HPTPbeta in modulating Ang-1-Tie2 signaling and endothelial cell survival.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Células Endoteliais
/
Receptor TIE-2
/
Angiopoietinas
/
Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article