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Qanash H, Li Y, Smith RH, Linask K, Young-Baird S, Hakami W, Keyvanfar K, Choy JS, Zou J, Larochelle A. Eltrombopag Improves Erythroid Differentiation in a Human Induced Pluripotent Stem Cell Model of Diamond Blackfan Anemia. Cells 2021; 10:734. [PMID: 33810313 PMCID: PMC8065708 DOI: 10.3390/cells10040734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 12/15/2022] Open
Abstract
Diamond Blackfan Anemia (DBA) is a congenital macrocytic anemia associated with ribosomal protein haploinsufficiency. Ribosomal dysfunction delays globin synthesis, resulting in excess toxic free heme in erythroid progenitors, early differentiation arrest, and pure red cell aplasia. In this study, DBA induced pluripotent stem cell (iPSC) lines were generated from blood mononuclear cells of DBA patients with inactivating mutations in RPS19 and subjected to hematopoietic differentiation to model disease phenotypes. In vitro differentiated hematopoietic cells were used to investigate whether eltrombopag, an FDA-approved mimetic of thrombopoietin with robust intracellular iron chelating properties, could rescue erythropoiesis in DBA by restricting the labile iron pool (LIP) derived from excessive free heme. DBA iPSCs exhibited RPS19 haploinsufficiency, reduction in the 40S/60S ribosomal subunit ratio and early erythroid differentiation arrest in the absence of eltrombopag, compared to control isogenic iPSCs established by CRISPR/Cas9-mediated correction of the RPS19 point mutation. Notably, differentiation of DBA iPSCs in the presence of eltrombopag markedly improved erythroid maturation. Consistent with a molecular mechanism based on intracellular iron chelation, we observed that deferasirox, a clinically licensed iron chelator able to permeate into cells, also enhanced erythropoiesis in our DBA iPSC model. In contrast, erythroid maturation did not improve substantially in DBA iPSC differentiation cultures supplemented with deferoxamine, a clinically available iron chelator that poorly accesses LIP within cellular compartments. These findings identify eltrombopag as a promising new therapeutic to improve anemia in DBA.
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Affiliation(s)
- Husam Qanash
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (H.Q.); (Y.L.); (R.H.S.); (W.H.)
- Department of Biology, Catholic University of America, Washington, DC 20064, USA;
- Department of Medical Laboratory Science, College of Applied Medical Sciences, The University of Hail, Hail 55476, Saudi Arabia
| | - Yongqin Li
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (H.Q.); (Y.L.); (R.H.S.); (W.H.)
| | - Richard H. Smith
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (H.Q.); (Y.L.); (R.H.S.); (W.H.)
| | - Kaari Linask
- iPSC Core Facility, NHLBI, NIH, Bethesda, MD 20892, USA; (K.L.); (J.Z.)
| | - Sara Young-Baird
- Eunice Kennedy Shriver, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA;
- National Institute of General Medical Sciences (NIGMS), NIH, Bethesda, MD 20892, USA
| | - Waleed Hakami
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (H.Q.); (Y.L.); (R.H.S.); (W.H.)
- Department of Biology, Catholic University of America, Washington, DC 20064, USA;
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan 45142, Saudi Arabia
| | - Keyvan Keyvanfar
- Clinical Flow Core Facility, NHLBI, NIH, Bethesda, MD 20892, USA;
| | - John S. Choy
- Department of Biology, Catholic University of America, Washington, DC 20064, USA;
| | - Jizhong Zou
- iPSC Core Facility, NHLBI, NIH, Bethesda, MD 20892, USA; (K.L.); (J.Z.)
| | - Andre Larochelle
- Cellular and Molecular Therapeutics Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (H.Q.); (Y.L.); (R.H.S.); (W.H.)
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