Regulation of tie2 expression by angiopoietin--potential feedback system
To study a potential feedback system in the angiopoietin (Ang)-Tie2 system, the authors examined effects of Ang1 and Ang2 on Tie2 expression on human umbilical vein endothelial cells (HUVECs) with or without stimulation by a potent inflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha). Ang1, but not Ang2, down-regulated Tie2 expression on HUVECs without TNF-alpha stimulation. Both Ang1 and Ang2 attenuated TNF-alpha-induced Tie2 up-regulation. Regulation of Tie2 expression by Ang1 or Ang2 was not dependent on phosphatidylinositol 3-kinase. The Ang-Tie2 system appears to have an autoregulatory feedback system that may be regulating the overall activity of the Tie2 system in both physiological and pathological conditions.
Medical Subject Headings
Angiopoietin-1 (metabolism, pharmacology); Angiopoietin-2 (metabolism, pharmacology); Cell Line; Down-Regulation (drug effects, physiology); Endothelial Cells (drug effects, metabolism); Feedback, Physiological (drug effects, physiology); Homeostasis (drug effects, physiology); Humans; Phosphatidylinositol 3-Kinases (drug effects, metabolism); Receptor, TIE-2 (drug effects, metabolism); Tumor Necrosis Factor-alpha (antagonists & inhibitors, metabolism); Up-Regulation (drug effects, physiology)
Endothelium : journal of endothelial cell research
Digital Object Identifier (DOI)
Hashimoto, Tomoki; Wu, Yongqin; Boudreau, Nancy; Li, Jenny; Matsumoto, Melissa; and Young, William, "Regulation of tie2 expression by angiopoietin--potential feedback system" (2004). Translational Neuroscience. 1695.