Hypoxia-inducible factor 2α regulates key neutrophil functions in humans, mice, and zebrafish

Blood. 2014 Jan 16;123(3):366-76. doi: 10.1182/blood-2013-05-500207. Epub 2013 Nov 6.

Abstract

Neutrophil lifespan and function are regulated by hypoxia via components of the hypoxia inducible factor (HIF)/von Hippel Lindau/hydroxylase pathway, including specific roles for HIF-1α and prolyl hydroxylase-3. HIF-2α has both distinct and overlapping biological roles with HIF-1α and has not previously been studied in the context of neutrophil biology. We investigated the role of HIF-2α in regulating key neutrophil functions. Human and murine peripheral blood neutrophils expressed HIF-2α, with expression up-regulated by acute and chronic inflammatory stimuli and in disease-associated inflammatory neutrophil. HIF2A gain-of-function mutations resulted in a reduction in neutrophil apoptosis both ex vivo, through the study of patient cells, and in vivo in a zebrafish tail injury model. In contrast, HIF-2α-deficient murine inflammatory neutrophils displayed increased sensitivity to nitrosative stress induced apoptosis ex vivo and increased neutrophil apoptosis in vivo, resulting in a reduction in neutrophilic inflammation and reduced tissue injury. Expression of HIF-2α was temporally dissociated from HIF-1α in vivo and predominated in the resolution phase of inflammation. These data support a critical and selective role for HIF-2α in persistence of neutrophilic inflammation and provide a platform to dissect the therapeutic utility of targeting HIF-2α in chronic inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cell Hypoxia
  • Gene Expression Regulation*
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Immunohistochemistry
  • Inflammation*
  • Mice
  • Mice, Inbred C57BL
  • Muramidase
  • Neutrophils / cytology
  • Neutrophils / metabolism*
  • Phagocytosis
  • Phenotype
  • RNA / metabolism
  • Respiratory Burst
  • Zebrafish

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Green Fluorescent Proteins
  • endothelial PAS domain-containing protein 1
  • RNA
  • Muramidase