Haematologica (May 2015)

Heme oxygenase-1 deficiency alters erythroblastic island formation, steady-state erythropoiesis and red blood cell lifespan in mice

  • Stuart T. Fraser,
  • Robyn G. Midwinter,
  • Lucy A. Coupland,
  • Stephanie Kong,
  • Birgit S. Berger,
  • Jia Hao Yeo,
  • Osvaldo Cooley Andrade,
  • Deborah Cromer,
  • Cacang Suarna,
  • Magda Lam,
  • Ghassan J. Maghzal,
  • Beng H. Chong,
  • Christopher R. Parish,
  • Roland Stocker

DOI
https://doi.org/10.3324/haematol.2014.116368
Journal volume & issue
Vol. 100, no. 5

Abstract

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Heme oxygenase-1 is critical for iron recycling during red blood cell turnover, whereas its impact on steady-state erythropoiesis and red blood cell lifespan is not known. We show here that in 8- to 14-week old mice, heme oxygenase-1 deficiency adversely affects steady-state erythropoiesis in the bone marrow. This is manifested by a decrease in Ter-119+-erythroid cells, abnormal adhesion molecule expression on macrophages and erythroid cells, and a greatly diminished ability to form erythroblastic islands. Compared with wild-type animals, red blood cell size and hemoglobin content are decreased, while the number of circulating red blood cells is increased in heme oxygenase-1 deficient mice, overall leading to microcytic anemia. Heme oxygenase-1 deficiency increases oxidative stress in circulating red blood cells and greatly decreases the frequency of macrophages expressing the phosphatidylserine receptor Tim4 in bone marrow, spleen and liver. Heme oxygenase-1 deficiency increases spleen weight and Ter119+-erythroid cells in the spleen, although α4β1-integrin expression by these cells and splenic macrophages positive for vascular cell adhesion molecule 1 are both decreased. Red blood cell lifespan is prolonged in heme oxygenase-1 deficient mice compared with wild-type mice. Our findings suggest that while macrophages and relevant receptors required for red blood cell formation and removal are substantially depleted in heme oxygenase-1 deficient mice, the extent of anemia in these mice may be ameliorated by the prolonged lifespan of their oxidatively stressed erythrocytes.