Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells

Stem Cells Dev. 2015 Jun 1;24(11):1342-51. doi: 10.1089/scd.2014.0402. Epub 2015 Mar 3.

Abstract

Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs.

Publication types

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

MeSH terms

  • Animals
  • Antioxidants / pharmacology*
  • Apoptosis*
  • Catalase / pharmacology*
  • Cells, Cultured
  • DNA Damage
  • Hematopoiesis*
  • Hematopoietic Stem Cells / drug effects*
  • Hematopoietic Stem Cells / metabolism
  • Hematopoietic Stem Cells / radiation effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Radiation, Ionizing
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction

Substances

  • Antioxidants
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • Catalase