Angiopoietin‐1 is an apoptosis survival factor for endothelial cells

Abstract

We examined the effect of angiopoietin-1 (Ang1) on apoptosis in human umbilical vein endothelial cells (HUVECs). Ang1 (5^1000 ng/ml) dose-dependently inhibited apoptosis under a serum-deprived state. A significant apoptotic inhibition occurred with as low as 50 ng/ml. Two hundred ng/ml of Ang1 inhibited to approximately 50% of the control apoptotic rates for 96 h. Furthermore, an augmented antiapoptotic effect of Ang1 by the addition of 20 ng/ml vascular endothelial growth factor was observed. This Ang1-induced strong antiapoptotic effect in endothelial cells is a novel and intriguing finding and could be an additional description of Ang1-induced direct biological function.z 1999 Federation of European Biochemical Societies.

Angiogenesis and Multiple Myeloma

“…Ang-1 does not induce endothelial cell proliferation directly [50], but acts as a survival factor for endothelial cells [51], induces vessel stabilization [52], tubule formation [53] and plays a key role in mediating interactions between endothelial and matrix cells [54]. Ang-1 is also produced by mast cells in the microenvironment that promotes plasma cell growth and stimulates angiogenesis together with tumor-derived VEGF [59].…”

Apoptosis in the vasculature: mechanisms and functional importance

“…Angiopoietin-1 ligation to its receptor Tie-2 has recently been shown to provide survival signals for the endothelial cell (Fujikawa et al, 1999;Hayes et al, 1999;Kwak et al, 1999). Growth-deprived endothelial cells are rescued from apoptosis by addition of angiopoietin-1.…”

Angiopoietin 1 inhibits ocular neovascularization and breakdown of the blood–retinal barrier

“…9 Ang1* promotes survival of cultured endothelial cells and stabilizes tubular networks. [10][11][12] Since Ang1* does not behave exactly like Ang1, it cannot be concluded that Ang1 has the same functions, but such studies at least provide some support for a potential Ang1 vascular maintenance function. However, there is also evidence suggesting that Ang1 may stimulate chemotaxis, tubule formation, and vascular sprouting and hence act as a proangiogenic agent.…”