Estrogen-induced redox sensitive Id3 signaling controls the growth of vascular cells

Atherosclerosis. 2008 May;198(1):12-21. doi: 10.1016/j.atherosclerosis.2007.12.048. Epub 2008 Feb 20.


In this study, we investigated a mechanism by which estrogen-induced oxidants control endothelial cell differentiation into tubelike structures via redox sensitive signaling molecule Id3. Using a matrigel cell culture, we determined whether superoxide or hydrogen peroxide signaled estrogen-induced tube formation. Overexpression of the superoxide scavenger MnSOD and the hydrogen peroxide scavenger catalase inhibited tube formation in estrogen treated endothelial cells. Since tube formation on matrigel is not specific for endothelial cells, we verified our results in a co-culture model that better represents tube formation in vivo. Antioxidants ebselen and N-acetylcysteine as well as overexpression of MnSOD and catalase inhibited tube formation in estrogen exposed endothelial cells co-cultured with fibroblasts. We previously showed that estrogen-induced mitochondrial oxidants depended on the cytoskeleton so we tested tube formation dependence on the cytoskeleton. Estrogen-induced tube formation was inhibited by the actin cytoskeleton disruptor cytochalasin D and the microtubule destabilizer colchicine. Estrogen increased Id3 phosphorylation which was reduced by catalase and N-acetylcysteine treatments. We determined the functional role of Id3 in tube formation by RNA intereference and showed Id3 siRNA to inhibit tube formation in estrogen exposed cells. The major novel findings presented here are that: (i) estrogen-induced tube formation requires the presence of Id3, a member of the helix-loop-helix family of transcriptional factors and (ii) estrogen increases Id3 phosphorylation via a redox-dependent process. Furthermore, these studies demonstrate Id3 to be an important signaling molecule in estrogen stimulated vascularization and may serve as a therapeutic target in the prevention and treatment of vasculoproliferative disorders.

MeSH terms

  • Antioxidants / pharmacology
  • Cells, Cultured
  • Coculture Techniques
  • Collagen
  • Dermis / cytology
  • Drug Combinations
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Estradiol / metabolism*
  • Estradiol / pharmacology
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Gene Expression / drug effects
  • Gene Expression / physiology
  • Humans
  • Inhibitor of Differentiation Proteins / genetics
  • Inhibitor of Differentiation Proteins / metabolism*
  • Laminin
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Neovascularization, Physiologic / drug effects
  • Neovascularization, Physiologic / physiology*
  • Oxidation-Reduction
  • Phosphorylation / drug effects
  • Proteoglycans
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Umbilical Veins / cytology


  • Antioxidants
  • Drug Combinations
  • Inhibitor of Differentiation Proteins
  • Laminin
  • Neoplasm Proteins
  • Proteoglycans
  • matrigel
  • ID3 protein, human
  • Estradiol
  • Collagen