Mechanisms of cell protection by heme oxygenase-1

Annu Rev Pharmacol Toxicol. 2010:50:323-54. doi: 10.1146/annurev.pharmtox.010909.105600.


Heme oxygenases (HO) catabolize free heme, that is, iron (Fe) protoporphyrin (IX), into equimolar amounts of Fe(2+), carbon monoxide (CO), and biliverdin. The stress-responsive HO-1 isoenzyme affords protection against programmed cell death. The mechanism underlying this cytoprotective effect relies on the ability of HO-1 to catabolize free heme and prevent it from sensitizing cells to undergo programmed cell death. This cytoprotective effect inhibits the pathogenesis of a variety of immune-mediated inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Biliverdine / physiology
  • Carbon Monoxide / physiology
  • Cytoprotection*
  • Gene Expression Regulation, Enzymologic
  • Heme / metabolism
  • Heme / toxicity
  • Heme Oxygenase-1 / genetics
  • Heme Oxygenase-1 / physiology*
  • Humans
  • Inflammation / prevention & control
  • Tumor Necrosis Factor-alpha / pharmacology


  • Tumor Necrosis Factor-alpha
  • Heme
  • Carbon Monoxide
  • Heme Oxygenase-1
  • Biliverdine