Insulin-like growth factor binding protein-3 mediates vascular repair by enhancing nitric oxide generation

Circ Res. 2009 Oct 23;105(9):897-905. doi: 10.1161/CIRCRESAHA.109.199059. Epub 2009 Sep 17.

Abstract

Rationale: Insulin-like growth factor binding protein (IGFBP)-3 modulates vascular development by regulating endothelial progenitor cell (EPC) behavior, specifically stimulating EPC cell migration. This study was undertaken to investigate the mechanism of IGFBP-3 effects on EPC function and how IGFBP-3 mediates cytoprotection following vascular injury.

Objective: To examine the mechanism of IGFBP-3-mediated repair following vascular injury.

Methods and results: We used 2 complementary vascular injury models: laser occlusion of retinal vessels in adult green fluorescent protein (GFP) chimeric mice and oxygen-induced retinopathy in mouse pups. Intravitreal injection of IGFBP-3-expressing plasmid into lasered GFP chimeric mice stimulated homing of EPCs, whereas reversing ischemia induced increases in macrophage infiltration. IGFBP-3 also reduced the retinal ceramide/sphingomyelin ratio that was increased following laser injury. In the OIR model, IGFBP-3 prevented cell death of resident vascular endothelial cells and EPCs, while simultaneously increasing astrocytic ensheathment of vessels. For EPCs to orchestrate repair, these cells must migrate into ischemic tissue. This migratory ability is mediated, in part, by endogenous NO generation. Thus, we asked whether the migratory effects of IGFBP-3 were attributable to stimulation of NO generation. IGFBP-3 increased endothelial NO synthase expression in human EPCs leading to NO generation. IGFBP-3 exposure also led to the redistribution of vasodilator-stimulated phosphoprotein, an NO regulated protein critical for cell migration. IGFBP-3-mediated NO generation required high-density lipoprotein receptor activation and stimulation of phosphatidylinositol 3-kinase/Akt pathway.

Conclusion: These studies support consideration of IGFBP-3 as a novel agent to restore the function of injured vasculature and restore NO generation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Astrocytes / metabolism
  • Cell Adhesion Molecules / metabolism
  • Cell Death
  • Cell Movement*
  • Cell Proliferation
  • Cells, Cultured
  • Ceramides / metabolism
  • Cerebral Arteries / metabolism
  • Cerebral Arteries / physiopathology
  • Cytoprotection
  • Disease Models, Animal
  • Endothelial Cells / metabolism*
  • Endothelial Cells / pathology
  • Female
  • Gene Transfer Techniques
  • Green Fluorescent Proteins / genetics
  • Humans
  • Infant, Newborn
  • Insulin-Like Growth Factor Binding Protein 3 / genetics
  • Insulin-Like Growth Factor Binding Protein 3 / metabolism*
  • Male
  • Mesenteric Arteries / metabolism
  • Mesenteric Arteries / physiopathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Microfilament Proteins / metabolism
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type III / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoproteins / metabolism
  • Pregnancy
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Neovascularization / metabolism*
  • Retinal Neovascularization / pathology
  • Retinal Neovascularization / physiopathology
  • Retinal Vessels / metabolism*
  • Retinal Vessels / pathology
  • Retinal Vessels / physiopathology
  • Retinopathy of Prematurity / metabolism*
  • Retinopathy of Prematurity / pathology
  • Retinopathy of Prematurity / physiopathology
  • Scavenger Receptors, Class B / metabolism
  • Signal Transduction
  • Sphingomyelins / metabolism
  • Stem Cells / metabolism*
  • Stem Cells / pathology
  • Vasodilation

Substances

  • Cell Adhesion Molecules
  • Ceramides
  • Insulin-Like Growth Factor Binding Protein 3
  • Microfilament Proteins
  • Phosphoproteins
  • SCARB1 protein, human
  • Scavenger Receptors, Class B
  • Sphingomyelins
  • vasodilator-stimulated phosphoprotein
  • Green Fluorescent Proteins
  • Nitric Oxide
  • NOS3 protein, human
  • Nitric Oxide Synthase Type III
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt