Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression

Nature. 2001 Nov 29;414(6863):550-4. doi: 10.1038/35107085.

Abstract

Alteration of gene expression is a crucial component of adaptive responses to hypoxia. These responses are mediated by hypoxia-inducible transcription factors (HIFs). Here we describe an inhibitory PAS (Per/Arnt/Sim) domain protein, IPAS, which is a basic helix-loop-helix (bHLH)/PAS protein structurally related to HIFs. IPAS contains no endogenous transactivation function but demonstrates dominant negative regulation of HIF-mediated control of gene expression. Ectopic expression of IPAS in hepatoma cells selectively impairs induction of genes involved in adaptation to a hypoxic environment, notably the vascular endothelial growth factor (VEGF) gene, and results in retarded tumour growth and tumour vascular density in vivo. In mice, IPAS was predominantly expressed in Purkinje cells of the cerebellum and in corneal epithelium of the eye. Expression of IPAS in the cornea correlates with low levels of expression of the VEGF gene under hypoxic conditions. Application of an IPAS antisense oligonucleotide to the mouse cornea induced angiogenesis under normal oxygen conditions, and demonstrated hypoxia-dependent induction of VEGF gene expression in hypoxic corneal cells. These results indicate a previously unknown mechanism for negative regulation of angiogenesis and maintenance of an avascular phenotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • COS Cells
  • Cell Hypoxia
  • Cerebellum / metabolism
  • Cornea / metabolism
  • DNA-Binding Proteins*
  • Endothelial Growth Factors / biosynthesis
  • Endothelial Growth Factors / genetics*
  • Gene Expression Regulation*
  • HeLa Cells
  • Helix-Loop-Helix Motifs
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Lymphokines / biosynthesis
  • Lymphokines / genetics*
  • Mice
  • Molecular Sequence Data
  • Neovascularization, Physiologic / genetics
  • Neovascularization, Physiologic / physiology
  • Oxygen / metabolism*
  • Protein Structure, Tertiary
  • Receptors, Aryl Hydrocarbon*
  • Recombinant Fusion Proteins / genetics
  • Sequence Homology, Amino Acid
  • Transcription Factors / biosynthesis
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors

Substances

  • ARNT protein, human
  • Arnt protein, mouse
  • DNA-Binding Proteins
  • Endothelial Growth Factors
  • HIF1A protein, human
  • Hif3a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Lymphokines
  • Receptors, Aryl Hydrocarbon
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Oxygen