HIF-1 alpha expression is associated with an atheromatous inflammatory plaque phenotype and upregulated in activated macrophages

Atherosclerosis. 2007 Dec;195(2):e69-75. doi: 10.1016/j.atherosclerosis.2007.05.026. Epub 2007 Jul 2.


Objective: Angiogenesis and inflammation are important features in atherosclerotic plaque destabilization. The transcription factor hypoxia-inducible factor-1 alpha (HIF-1 alpha) is a key regulator of angiogenesis and is also involved in inflammatory reactions. We studied HIF-1 alpha expression in different atherosclerotic plaque phenotypes.

Methods and results: HIF-1 alpha expression was observed in 18/37 (49%) carotid and in 9/15 (60%) femoral endarterectomy specimens. Expression of HIF-1 alpha was associated with the presence of a large extracellular lipid core (P=0.03) and macrophages (P=0.02). HIF-1 alpha co-localized with vascular endothelial growth factor (VEGF), an important downstream target of HIF-1 alpha. In addition, a strong association was observed between expression levels of HIF-1 alpha and VEGF (P=0.001). The average number of plaque microvessels was higher in plaques with no or minor HIF-1 alpha staining than in plaques with moderate or heavy HIF-1 alpha staining (P=0.03). In human macrophages, lipopolysaccharide activation induced HIF-1 alpha expression. In embryonic fibroblasts derived from wild-type mice, lipopolysaccharide activation induced an increase in HIF-1 alpha mRNA, whereas in Toll-like receptor 4 defective embryonic fibroblasts no effect was observed after lipopolysaccharide stimulation.

Conclusions: In atherosclerotic plaque, the transcription factor HIF-1 alpha is associated with an atheromatous inflammatory plaque phenotype and with VEGF expression. HIF-1 alpha expression is upregulated in activated macrophages under normoxic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carotid Artery Diseases / metabolism*
  • Carotid Artery Diseases / physiopathology
  • Cells, Cultured
  • Endarterectomy, Carotid
  • Femoral Artery / metabolism
  • Femoral Artery / pathology
  • Fibroblasts / metabolism
  • Foam Cells / metabolism*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Immunohistochemistry
  • Macrophages / metabolism*
  • Mice
  • Monocytes, Activated Killer / metabolism
  • Neovascularization, Pathologic / metabolism
  • Phenotype
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / metabolism


  • HIF1A protein, human
  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A