Iron status influences the response of cord blood megakaryocyte progenitors to eltrombopag in vitro

Zhi Jian Liu, Emoke Deschmann, Haley E. Ramsey, Henry A. Feldman, Bethan Psaila, Nichola Cooper, Evangelia Vlachodimitropoulou, John Porter, James Bussel, Michael Georgieff, Martha Sola-Visner

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Eltrombopag (ELT) is a thrombopoietic agent approved for immune thrombocytopenia and also a potent iron chelator. Here we found that ELT exhibited dose-dependent opposing effects on in vitro megakaryopoiesis: low concentrations (≤6 µM, ELT6) stimulated megakaryopoiesis, but high concentrations (30 µM, ELT30) suppressed megakaryocyte (MK) differentiation and proliferation. The suppressive effects of ELT30 were reproduced by other iron chelators, supporting iron chelation as a likely mechanism. During MK differentiation, committed MK progenitors (CD34+/CD41+ and CD34-/CD41+ cells) were significantly more sensitive than undifferentiated progenitors (CD34+/CD41- cells) to the suppressive effects of ELT30, which resulted from both decreased proliferation and increased apoptosis. The antiproliferative effects of ELT30 were reversed by increased iron in the culture, as were the proapoptotic effects when exposure to ELT30 was short. Because committed MK progenitors exhibited the highest proliferative rate and the highest sensitivity to iron chelation, we tested whether their iron status influenced their response to ELT during rapid cell expansion. In these studies, iron deficiency reduced the proliferation of CD41+ cells in response to all ELT concentrations. Severe iron deficiency also reduced the number of MKs generated in response to high thrombopoietin concentrations by ∼50%, compared with iron-replete cultures. Our findings support the hypothesis that although iron deficiency can stimulate certain cells and steps in megakaryopoiesis, it can also limit the proliferation of committed MK progenitors, with severity of iron deficiency and degree of thrombopoietic stimulation influencing the ultimate output. Further studies are needed to clarify how megakaryopoiesis, iron deficiency, and ELT stimulation are clinically interrelated.

Original languageEnglish (US)
Pages (from-to)13-27
Number of pages15
JournalBlood Advances
Issue number1
StatePublished - Jan 11 2022

Bibliographical note

Publisher Copyright:
© 2021 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.


Dive into the research topics of 'Iron status influences the response of cord blood megakaryocyte progenitors to eltrombopag in vitro'. Together they form a unique fingerprint.

Cite this