1. Low iron promotes megakaryocytic commitment of megakaryocytic-erythroid progenitors in humans and mice.
- Author
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Xavier-Ferrucio J, Scanlon V, Li X, Zhang PX, Lozovatsky L, Ayala-Lopez N, Tebaldi T, Halene S, Cao C, Fleming MD, Finberg KE, and Krause DS
- Subjects
- Anemia, Iron-Deficiency complications, Animals, Cell Proliferation, Humans, Iron, Megakaryocyte Progenitor Cells cytology, Megakaryocytes cytology, Mice, Mice, Knockout, Thrombocytosis etiology, Thrombocytosis metabolism, Anemia, Iron-Deficiency metabolism, Cell Differentiation physiology, Megakaryocyte Progenitor Cells metabolism, Megakaryocytes metabolism
- Abstract
The mechanisms underlying thrombocytosis in patients with iron deficiency anemia remain unknown. Here, we present findings that support the hypothesis that low iron biases the commitment of megakaryocytic (Mk)-erythroid progenitors (MEPs) toward the Mk lineage in both human and mouse. In MEPs of transmembrane serine protease 6 knockout (Tmprss6-/-) mice, which exhibit iron deficiency anemia and thrombocytosis, we observed a Mk bias, decreased labile iron, and decreased proliferation relative to wild-type (WT) MEPs. Bone marrow transplantation assays suggest that systemic iron deficiency, rather than a local role for Tmprss6-/- in hematopoietic cells, contributes to the MEP lineage commitment bias observed in Tmprss6-/- mice. Nontransgenic mice with acquired iron deficiency anemia also show thrombocytosis and Mk-biased MEPs. Gene expression analysis reveals that messenger RNAs encoding genes involved in metabolic, vascular endothelial growth factor, and extracellular signal-regulated kinase (ERK) pathways are enriched in Tmprss6-/- vs WT MEPs. Corroborating our findings from the murine models of iron deficiency anemia, primary human MEPs exhibit decreased proliferation and Mk-biased commitment after knockdown of transferrin receptor 2, a putative iron sensor. Signal transduction analyses reveal that both human and murine MEP have lower levels of phospho-ERK1/2 in iron-deficient conditions compared with controls. These data are consistent with a model in which low iron in the marrow environment affects MEP metabolism, attenuates ERK signaling, slows proliferation, and biases MEPs toward Mk lineage commitment., (© 2019 by The American Society of Hematology.)
- Published
- 2019
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