Angiopoietin-1 acting via the Tie 2 receptor induces Akt phosphorylation and survivin up-regulation, protecting endothelial cells from apoptosis.
Does Angiopoietin-1 prevent endothelial cell apoptosis via the Akt/survivin pathway?
Angiopoietin-1 promotes endothelial cell survival and stabilizes vascular structures during angiogenesis by activating the Akt/survivin anti-apoptotic pathway.
A productive angiogenic response must couple to the survival machinery of endothelial cells to preserve the integrity of newly formed vessels. Angiopoietin-1 (Ang-1) is an endothelium-specific ligand essential for embryonic vascular stabilization, branching morphogenesis, and post-natal angiogenesis, but its contribution to endothelial cell survival has not been completely elucidated. Here we show that Ang-1 acting via the Tie 2 receptor induces phosphorylation of the survival serine-threonine kinase, Akt (or protein kinase B). This is associated with up-regulation of the apoptosis inhibitor, survivin, in endothelial cells and protection of endothelium from death-inducing stimuli. Moreover, dominant negative survivin negates the ability of Ang-1 to protect cells from undergoing apoptosis. The activation of anti-apoptotic pathways mediated by Akt and survivin in endothelial cells may contribute to Ang-1 stabilization of vascular structures during angiogenesis, in vivo.
Papapetropoulos et al. (Wed,) conducted a other in Endothelial cell apoptosis. Angiopoietin-1 was evaluated on Endothelial cell apoptosis and survival. Angiopoietin-1 acting via the Tie 2 receptor induces Akt phosphorylation and survivin up-regulation, protecting endothelial cells from apoptosis.