Erythroid Lineage-Restricted Expression of Jak2V617F Is Sufficient to Induce a Myeloproliferative Disease in Mice,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3861-3861
Author(s):  
Hajime Akada ◽  
Saeko Hamada ◽  
Golam Mohi
Keyword(s):  
Stem Cells ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Myeloproliferative Neoplasms ◽  
Jak2v617f Mutation ◽  
Target Cells ◽  
Dependent Manner ◽  
Myeloproliferative Disease ◽  
Erythroid Progenitors ◽  
Hematopoietic Stem

Abstract Abstract 3861 A somatic point mutation (V617F) in the JAK2 tyrosine kinase was found in most cases of Ph-negative myeloproliferative neoplasms (MPNs) including ∼95% patients with polycythemia vera (PV) and 50–60% patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). To investigate the contribution of JAK2V617F in MPNs, we generated a conditional Jak2V617F knock-in mouse (Akada et al., Blood 2010; 115: 3589–3597). Expression of Jak2V617F in all hematopoietic compartments including the hematopoietic stem cells (HSC) resulted in a PV-like disease associated with a marked expansion of erythroid progenitors in the bone marrow and spleen. Since Jak2 is essential for normal erythropoiesis and expression of Jak2V617F mutant enhances erythropoiesis, so we asked if erythroid progenitors are actual target cells for Jak2V617F mutation. To address this question, we have specifically expressed Jak2V617F in erythroid progenitors using the EpoR-Cre mice. Expression of heterozygous Jak2V617F in erythroid progenitors resulted in a polycythemia-like phenotype characterized by increase in hematocrit and hemoglobin, increased red blood cells, Epo-independent erythroid colonies, and splenomegaly. Erythroid lineage-specific expression of homozygous Jak2V617F resulted in significantly greater increase in hematocrit, hemoglobin, red blood cells, Epo-independent erythroid colonies, and splenomegaly compared to heterozygous Jak2V617F expression. These results suggest that erythroid lineage-restricted expression of Jak2V617F is sufficient to induce a polycythemia-like disease in a gene-dose dependent manner. However, transplantation of Jak2V617F-expressing erythroid progenitors (c-kithighTer119lowCD71high or c-kitlowTer119highCD71high) from the diseased mice into lethally irradiated recipients could not transfer the disease suggesting that Jak2V617F mutation does not confer self-renewal capacity to erythroid progenitors. We also observed that only Jak2V617F-expressing HSC has the unique capacity to serially transplant the myeloproliferative disease in mice. Taken together, our results suggest that HSCs are the disease-initiating cancer stem cells and erythroid progenitors are the target cells in Jak2V617F-evoked MPN. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Merocyanine 540-sensitized photoinactivation of human erythrocytes parasitized by Plasmodium falciparum

Blood ◽  
1992 ◽  
Vol 80 (1) ◽  
pp. 21-24 ◽  
Author(s):  
OM Smith ◽  
SA Dolan ◽  
JA Dvorak ◽  
TE Wellems ◽  
F Sieber
Keyword(s):  
Stem Cells ◽  
Plasmodium Falciparum ◽  
Hematopoietic Stem Cells ◽  
Red Blood Cells ◽  
Human Blood ◽  
Blood Cells ◽  
Potential Usefulness ◽  
Hematopoietic Stem ◽  
Infected Blood ◽  
Merocyanine 540

The purpose of this study was to evaluate the photosensitizing dye merocyanine 540 (MC540) as a means for extracorporeal purging of Plasmodium falciparum-infected erythrocytes from human blood. Parasitized red blood cells bound more dye than nonparasitized cells, and exposure to MC540 and light under conditions that are relatively well tolerated by normal erythrocytes and normal pluripotent hematopoietic stem cells reduced the concentration of parasitized cells by as much as 1,000-fold. Cells parasitized by the chloroquine- sensitive HB3 clone and the chloroquine-resistant Dd2 clone of P falciparum were equally susceptible to MC540-sensitized photolysis. These data suggest the potential usefulness of MC540 in the purging of P falciparum-infected blood.

Differential Requirements for Survivin in Hematopoietic Cell Development.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1257-1257
Author(s):  
Yanfei Xu ◽  
Sandeep Gurbuxani ◽  
Ganesan Keerthivasan ◽  
Amittha Wickrema ◽  
John D. Crispino
Keyword(s):  
Cell Cycle ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Caspase 3 ◽  
Terminal Differentiation ◽  
Dependent Manner ◽  
Erythroid Cells ◽  
Hematopoietic Stem ◽  
Stage Of Development ◽  
Primary Mouse

Abstract The development of the complete repertoire of blood cells from a common progenitor, the hematopoietic stem cell, is a tightly controlled process that is regulated, in part, by the activity of lineage specific transcription factors. Despite our knowledge of these factors, the mechanisms that regulate the formation and growth of distinct, but closely related lineages, such as erythroid cells and megakaryocytes, remain largely uncharacterized. Here we show that Survivin, a member of the inhibitor of apoptosis (IAP) family that also plays an essential role in cytokinesis, is differentially expressed during erythroid versus megakaryocyte development. Erythroid cells express Survivin throughout their maturation, up to the terminal stage of differentiation (orthochromatic), even after the cells exit the cell cycle. This is surprising because Survivin is generally expressed in a cell cycle dependent manner and not thought to be expressed in terminally differentiated cells. In contrast, purified murine megakaryocytes express nearly 5-fold lower levels of Survivin mRNA compared to erythroid cells. To investigate whether Survivin is involved in the differentiation and/or survival of hematopoietic progenitors, we infected primary mouse bone marrow cells with retroviruses harboring either the human Survivin cDNA or a mouse Survivin shRNA, and then induced erythroid and megakaryocyte differentiation in both liquid culture and colony-forming assays. These studies revealed that overexpression of Survivin promoted the terminal differentiation of red blood cells, while its reduction, by RNA interference, inhibited their differentiation. In contrast, downregulation of Survivin facilitated the expansion of megakaryocytes, and its overexpression antagonized megakaryocyte formation. In addition, consistent with a role for survivin in erythropoiesis, downregulation of Survivin expression in MEL cells led to a block in terminal differentiation. Finally, since caspase activity is known to be required for erythroid maturation, we investigated whether survivin associated with cleaved caspase-3 in erythroid cells. Immunofluorescence revealed that Survivin and cleaved caspase-3 co-localized to discrete foci within the cytoplasm of erythroid cells at the orthochromatic stage of development. Based on these findings, we hypothesize that Survivin cooperates with cleaved caspase-3 in terminal maturation of red blood cells. Together, our findings demonstrate that Survivin plays multiple, distinct roles in hematopoiesis.

Ex vivo generation of fully mature human red blood cells from hematopoietic stem cells

2005 ◽  
Vol 23 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Marie-Catherine Giarratana ◽  
Ladan Kobari ◽  
Hélène Lapillonne ◽  
David Chalmers ◽  
Laurent Kiger ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Ex Vivo ◽  
Hematopoietic Stem ◽  
Human Red Blood Cells

scholarly journals In VitroLarge Scale Production of Human Mature Red Blood Cells from Hematopoietic Stem Cells by Coculturing with Human Fetal Liver Stromal Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jiafei Xi ◽  
Yanhua Li ◽  
Ruoyong Wang ◽  
Yunfang Wang ◽  
Xue Nan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cord Blood ◽  
Red Blood Cells ◽  
Stromal Cells ◽  
Blood Cells ◽  
Fetal Liver ◽  
Erythroid Differentiation ◽  
Erythroid Cells ◽  
Hematopoietic Stem

In vitromodels of human erythropoiesis are useful in studying the mechanisms of erythroid differentiation in normal and pathological conditions. Here we describe an erythroid liquid culture system starting from cord blood derived hematopoietic stem cells (HSCs). HSCs were cultured for more than 50 days in erythroid differentiation conditions and resulted in a more than 109-fold expansion within 50 days under optimal conditions. Homogeneous erythroid cells were characterized by cell morphology, flow cytometry, and hematopoietic colony assays. Furthermore, terminal erythroid maturation was improved by cosculturing with human fetal liver stromal cells. Cocultured erythroid cells underwent multiple maturation events, including decrease in size, increase in glycophorin A expression, and nuclear condensation. This process resulted in extrusion of the pycnotic nuclei in up to 80% of the cells. Importantly, they possessed the capacity to express the adult definitiveβ-globin chain upon further maturation. We also show that the oxygen equilibrium curves of the cord blood-differentiated red blood cells (RBCs) are comparable to normal RBCs. The large number and purity of erythroid cells and RBCs produced from cord blood make this method useful for fundamental research in erythroid development, and they also provide a basis for future production of available RBCs for transfusion.

Homeostatic Role of the Krüppel-Like Factor 4 (KLF4) in Proliferation and Differentiation of Primitive Hematopoietic Progenitor Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1497-1497 ◽  
Author(s):  
Chun Shik Park ◽  
Takeshi Yamada ◽  
H. Daniel Lacorazza
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Progenitor Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Proliferative Potential ◽  
Dependent Manner ◽  
Hematopoietic Stem ◽  
Deficient Mice

Abstract Abstract 1497 Poster Board I-520 KLF4 is a tumor suppressor in the gastrointestinal tract known to induce cell cycle arrest in a cell context dependent manner. We recently reported that KLF4 maintains quiescence of T lymphocytes downstream of T-cell receptor signaling (Yamada et al., Nature Immunology, 2009). The role of KLF4 in reprogramming adult somatic cells into pluripotent stem cells along with Oct3/4, c-Myc and Sox2 suggests that KLF4 restricts proliferation of undifferentiated cells. In spite of a redundant role of KLF4 in fetal liver hematopoietic stem cells (HSC), its role in the maintenance of adult bone marrow HSCs has not been studied yet. To study the role of KLF4 in the hematopoietic system we used gain- and loss-of-function mouse models. Retroviral transfer of KLF4 into wild type bone marrow (BM) cells led to significant reduction of colony forming units (CFU) in methylcellulose cultures due to increased apoptosis and lower proliferation. Then, Mx1-Cre was used to induce deletion of Klf4-floxed mice by polyI:C administration. Analysis of peripheral blood cells up to 6-9 months post polyI:C administration showed significant reduction of monocytes, as previously reported, and expansion of CD8+CD44+ T cells due to their increased proliferative potential. BM cells from Klf4-deficient mice exhibited increased number of myeloid progenitor cells measured by flow cytometry (Lin-Sca-1-c-kit+FcRII/III+CD34+ cells), CFU and CFU-S8. Cytoablation with 5-fluorouracil (5-FU) showed lower nadir of peripheral white blood cells in Klf4-deficient mice compared to control mice. In spite of normal multilineage reconstitution in BM transplants experiments, competitive reconstitution with Klf4-deficient and normal BM cells resulted in reduced contribution of Klf4-deficient cells to peripheral blood, likely due to homing and proliferative differences. Collectively, our data shows that KLF4 has an important role in function of hematopoietic stem and progenitor cells. Disclosures: No relevant conflicts of interest to declare.

Depletion of Jak2V617F MPN Stem Cells by IFNα in a Murine Model of Polycythemia Vera

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 806-806
Author(s):  
Ann Mullally ◽  
Claudia Bruedigam ◽  
Dirk Heckl ◽  
Luke Poveromo ◽  
Florian H. Heidel ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Murine Model ◽  
Myeloproliferative Neoplasms ◽  
Spleen Weight ◽  
Erythroid Progenitors ◽  
Hematopoietic Stem ◽  
Type 1 Interferon

Abstract Abstract 806 Interferon alpha (IFNα) is an effective treatment for patients with myeloproliferative neoplasms (MPN). In addition to inducing hematological responses in most MPN patients, IFNα reduces the JAK2V617F allelic burden and can render the JAK2V617F mutant clone undetectable in some patients. The mechanism underlying these responses is incompletely understood and whether the molecular responses that are seen occur due to the effects of IFNα on JAK2V617F mutant stem cells is debated. Using a murine model of Jak2V617F MPN, we investigated the effects of IFNα on Jak2V617F MPN stem cells in vivo. Chimeric transplant recipients were generated with purified stem cell enriched populations (lin−Kit+Sca1+) and these were treated for 4 weeks with either IFNα or vehicle control. IFNα treatment caused a reduction in extramedullary hematopoiesis (spleen weight, vehicle 262mg vs IFNα 192mg, p<0.01), hematocrit (vehicle 76.0% vs IFNα 65.5%, p<0.05) and white blood cell count (vehicle 13.9×109/L vs IFNα 7.5×109/L, p<0.01) in this disease model. IFNα treatment caused a reduction in early (CD71+Ter119+) erythroid progenitors that had accumulated in the spleen of Jak2V617F mice. IFNα treatment caused selective depletion of Jak2V617F MPN hematopoietic stem cells (HSC, lin−kit+Sca1+CD150+CD48−) over time and this was associated with reduced Jak2V617F chimerism in the long-term HSC compartment (Jak2V617F chimerism Vehicle 41.4% vs. IFNα 23.9%, p<0.05). IFNα treatment impaired the transmission of Jak2V617F-MPN and reduced Jak2V617F chimerism in transplanted recipient mice, demonstrating functional depletion of disease-specific stem cells. Mechanistically, IFNα treatment preferentially induced cell-cycle activation of Jak2V617F mutant long-term HSCs. Gene expression profiling revealed relative enrichment of cell cycle genes and depletion of quiescence related genes in IFNα treated Jak2V617F HSC compared to IFNα treated WT HSC. IFNα treatment promoted a predetermined terminal erythroid-lineage differentiation program within myeloid progenitor cells. The effects on Jak2V617F long-term HSC were absent in Jak2V617F+/−IFNAR1−/− (lacking the type 1 interferon receptor) chimeric mice demonstrating that the effects of IFNα treatment were cell autonomous and specific for type 1 interferon signalling. These findings provide insights into the differential effects of IFNα on Jak2V617F mutant and normal hematopoiesis and suggest that IFNα achieves molecular remissions in MPN patients through its effects on MPN stem cells. Furthermore, these results support combinatorial therapeutic approaches in MPN, by concurrently depleting dormant JAK2V617F MPN-propagating stem cells with IFNα and targeting the proliferating downstream progeny with JAK2-inhibitors or cytotoxic chemotherapy. Disclosures: Heidel: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ebert:Celgene: Consultancy; Genoptix: Consultancy.

RUNX1 and NF-E2 Transcriptional Upregulation Is Not Specific For Myeloproliferative Neoplasms But Is Seen In Those Polycythemic Disorders With Augmented HIFs Signaling

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2177-2177
Author(s):  
Katarina Kapralova ◽  
Lucie Lanikova ◽  
Felipe R Lorenzo V ◽  
Monika Horvathova ◽  
Vladimir Divoky ◽  
...  
Keyword(s):  
Stem Cells ◽  
Myeloproliferative Neoplasms ◽  
Cell Mass ◽  
Homozygous Mutation ◽  
Erythroid Progenitors ◽  
Gain Of Function ◽  
Erythroid Progenitor ◽  
Hematopoietic Stem ◽  
Exon 2 ◽  
Secondary Polycythemia

Abstract RUNX1 and NF-E2 are transcription factors that regulate hematopoietic stem cell homeostasis. It has been reported that increased RUNX1 expression in the granulocytes is present in all three classical myeloproliferative neoplasms (MPN): polycythemia vera (PV), essential thrombocythemia and primary myelofibrosis (Wang et al, Blood 2010), and that elevated NF-E2 promotes erythropoietin (EPO)-independent erythroid maturation of hematopoietic stem cells in vitro (Bogeska et al, Stem Cells Transl Med 2013). A mouse model overexpressing the NF-E2 transgene in hematopoietic cells was reported to be a new model of myeloproliferative neoplasms (Kaufmann et al, J Exp Med 2012). Polycythemic states can be divided into primary polycythemias, characterized by intrinsically hyperproliferative erythroid progenitors that are hypersensitive to EPO, and secondary polycythemias, wherein erythroid progenitors respond normally to EPO but circulating EPO is elevated or inappropriately normal for the level of increased red cell mass. Some congenital disorders including those with mutations in the hypoxia sensing pathway may share features of both primary and secondary polycythemias. We considered the possibility that increased transcripts of RUNX1 and NF-E2 might be the feature of other primary polycythemic states as well. We report a study of 19 polycythemic patients with primary or secondary polycythemia with diverse etiologies including mutations in positive and negative regulators of hypoxia sensing pathway. RUNX1 and NF-E2 transcripts were quantitated in granulocytes and BFU-E colonies by qPCR. All primary polycythemic patients had erythroid progenitors hypersensitive to or independent to EPO; all secondary polycythemic subjects had normal erythroid progenitor response to EPO. RUNX1 and NF-E2 gene transcripts were increased in granulocytes and BFU-E colonies in all PV patients, two unrelated subjects with the VHLR200W homozygous mutation (Chuvash polycythemia), one polycythemic patient homozygous for the VHLP138L exon 2 mutation, and a patient with the HIF2αM535V gain-of-function mutation. We also found upregulated expression of RUNX1 and NF-E2 in granulocytes and BFU-Es from a polycythemic patient (with no detectable EPOR, JAK2V617F or JAK2 exon 12 mutations and low level of EPO < 1 mU/mL) who was heterozygous for a SNP in exon 3 (rs147341899) in the LNK gene. We examined transcripts of RUNX1 and NF-E2 genes in granulocytes from two Croatian polycythemic patients with a homozygous VHLH191D exon 3 mutation whose erythroid progenitors were not hypersensitive to EPO and whose RUNX1, but not NF-E2, transcript was increased. We found similar results in two compound heterozygotes for VHLT124A exon 2 and VHLL188V exon 3 mutations. These two polycythemic siblings had hypersensitive erythroid colonies, increased RUNX1 transcripts and decreased NF-E2 transcripts in granulocytes. RUNX1 and NF-E2 transcripts were normal in two subjects with primary polycythemia due to the EPOR gain-of-function EPORQ434Xmutation, and in five unrelated subjects with secondary polycythemia. We next examined granulocyte transcripts of HIF-regulated genes: TFRC, SLC2A1, VEGF, BNIP3 and HK1, and found them to be increased in all PV patients and all studied polycythemic patients with VHL, HIF2α or LNK mutations, but not in polycythemic EPORQ434Xpatients or five patients with secondary polycythemia. Increased transcripts of HIF regulated genes are compatible with the previously unappreciated Warburg effect in PV (see S. Sana's Abstract at this ASH meeting). We propose that increased expression of RUNX1 and NF-E2 is not specific for myeloproliferative neoplasms but also is not universal for primary polycythemic disorders. Therefore, increased expression of RUNX1 and NF-E2 do not seem to be underlying mechanism for MPNs development but rather represent factors associated with diverse primary polycythemia states with augmented HIF signaling. (Note: KK and LL contributed equally to this work.) This work was supported by 1P01CA108671-O1A2 (NCI) Myeloproliferative Disorders (MPD) Consortium (PI Ron Hoffman) project#1 (PI Prchal) and the Leukemia & Lymphoma Society. Work by KK, LL, MH and VD was in part supported by the European Structural Funds (project CZ.1.07/2.3.00/20.0164 and CZ.1.07/2.3.00/30.0041), grant LF_2013_010 and by Czech Science Foundation (Project-P301/12/1503). Disclosures: No relevant conflicts of interest to declare.

scholarly journals Analysis of Jak2 signaling reveals resistance of mouse embryonic hematopoietic stem cells to myeloproliferative disease mutation

Blood ◽  
2016 ◽  
Vol 127 (19) ◽  
pp. 2298-2309 ◽  
Author(s):  
Maria I. Mascarenhas ◽  
Wendi A. Bacon ◽  
Chrysa Kapeni ◽  
Simon R. Fitch ◽  
Gillian Kimber ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Jak2v617f Mutation ◽  
Pi3k Signaling ◽  
Myeloproliferative Disease ◽  
Hematopoietic Stem ◽  
Disease Mutation ◽  
Key Points

Key Points Emerging HSCs require Jak2 and Pi3k signaling for proliferation and survival. Embryonic HSCs are unaffected by the JAK2V617F mutation.

scholarly journals ABCG2 Is Overexpressed on Red Blood Cells in Ph-Negative Myeloproliferative Neoplasms and Potentiates Ruxolitinib-Induced Apoptosis

2021 ◽  
Vol 22 (7) ◽  
pp. 3530
Author(s):  
Ralfs Buks ◽  
Mégane Brusson ◽  
Sylvie Cochet ◽  
Tatiana Galochkina ◽  
Bruno Cassinat ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
High Risk ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Kinase Inhibitor ◽  
Myeloproliferative Neoplasms ◽  
Specific Inhibitor ◽  
Risk Scores ◽  
Interferon Α ◽  
Hematopoietic Stem

Myeloproliferative neoplasms (MPNs) are a group of disorders characterized by clonal expansion of abnormal hematopoietic stem cells leading to hyperproliferation of one or more myeloid lineages. The main complications in MPNs are high risk of thrombosis and progression to myelofibrosis and leukemia. MPN patients with high risk scores are treated by hydroxyurea (HU), interferon-α, or ruxolitinib, a tyrosine kinase inhibitor. Polycythemia vera (PV) is an MPN characterized by overproduction of red blood cells (RBCs). ABCG2 is a member of the ATP-binding cassette superfamily transporters known to play a crucial role in multidrug resistance development. Proteome analysis showed higher ABCG2 levels in PV RBCs compared to RBCs from healthy controls and an additional increase of these levels in PV patients treated with HU, suggesting that ABCG2 might play a role in multidrug resistance in MPNs. In this work, we explored the role of ABCG2 in the transport of ruxolitinib and HU using human cell lines, RBCs, and in vitro differentiated erythroid progenitors. Using stopped-flow analysis, we showed that HU is not a substrate for ABCG2. Using transfected K562 cells expressing three different levels of recombinant ABCG2, MPN RBCs, and cultured erythroblasts, we showed that ABCG2 potentiates ruxolitinib-induced cytotoxicity that was blocked by the ABCG2-specific inhibitor KO143 suggesting ruxolitinib intracellular import by ABCG2. In silico modeling analysis identified possible ruxolitinib-binding site locations within the cavities of ABCG2. Our study opens new perspectives in ruxolitinib efficacy research targeting cell types depending on ABCG2 expression and polymorphisms among patients.

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