scholarly journals Hyperleukocytic Acute Leukemia Circulating Exosomes Regulate HSCs and BM-MSCs

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanmei Yang ◽  
Haiping He ◽  
Jigang He ◽  
Xuezhong Gu ◽  
Peng Hu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Leukemia ◽  
Support Function ◽  
Hematopoietic Differentiation ◽  
Related Factors ◽  
Hematopoietic Stem ◽  
Colony Forming Unit ◽  
Dkk1 Expression ◽  
Marrow Mesenchymal Stem Cells

Hyperleukocytic acute leukemia (HLAL) circulating exosomes are delivered to hematopoietic stem cells (HSCs) and bone marrow mesenchymal stem cells (BM-MSCs), thereby inhibiting the normal hematopoietic process. In this paper, we have evaluated and explored the effects of miR-125b, which is carried by HLAL-derived exosomes, on the hematopoietic function of HSCs and BM-MSCs. For this purpose, we have isolated exosomes from the peripheral blood of HLAL patients and healthy volunteers. Then, we measured the level of miR-125b in exosomes cocultured exosomes with HSCs and BM-MSCs. Moreover, we have used miR-125b inhibitors/mimic for intervention and then measured miR-125b expression and colony forming unit (CFU). Apart from it, HSC and BM-MSC hematopoietic-related factors α-globulin, γ-globulin, CSF2, CRTX4 and CXCL12, SCF, IGF1, and DKK1 expression were measured. Evaluation of the miR-125b and BAK1 targeting relationship, level of miR-125b, and expression of hematopoietic-related genes was performed after patients are treated with miR-125b mimic and si-BAK1. We have observed that miR-125b was upregulated in HLAL-derived exosomes. After HLAL-exosome acts on HSCs, the level of miR-125b is upregulated, reducing CFU and affecting the expression of α-globulin, γ-globulin, CSF2, and CRCX4. For BM-MSCs, after the action of HLAL-exo, the level of miR-125b is upregulated and affected the expression of CXCL12, SCF, IGF1, and DKK1. Exosomes derived from HLAL carry miR-125b to target and regulate BAK1. Further study confirmed that miR-125b and BAK1mimic reduced the expression of miR-125b and reversed the effect of miR-125b mimic on hematopoietic-related genes. These results demonstrated that HLAL-derived exosomes carrying miR-125b inhibit the hematopoietic differentiation of HSC and hematopoietic support function of BM-MSC through BAK1.

Second Allogeneic Bone Marrow Transplantation in Acute Leukemia: Results of a Survey by the European Cooperative Group for Blood and Marrow Transplantation

2001 ◽  
Vol 19 (16) ◽  
pp. 3675-3684 ◽  
Author(s):  
Alberto Bosi ◽  
Daniele Laszlo ◽  
Myriam Labopin ◽  
Josy Reffeirs ◽  
Mauricette Michallet ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Leukemia ◽  
Marrow Transplantation ◽  
Chronic Gvhd ◽  
Allogeneic Bone Marrow Transplantation ◽  
Allogeneic Bone ◽  
Cooperative Group ◽  
Hematopoietic Stem ◽  
Blood And Marrow Transplantation

PURPOSE: Leukemic relapse is the most frequent cause of treatment failure after allogeneic hematopoietic stem-cell transplantation (HSCT). To identify prognostic factors affecting the outcome of second HSCT, we performed a retrospective study on patients with acute leukemia (AL) undergoing second HSCT who reported to the Acute Leukemia Working Party of the European Cooperative Group for Blood and Marrow Transplantation registry. PATIENTS AND METHODS: One hundred seventy patients who received second HSCTs for AL experienced relapse after first HSCTs were performed from 1978 to 1997. Status at second HSCT, time between first and second HSCT, conditioning regimen, source of stem cells, treatment-related mortality (TRM), acute graft-versus-host disease (aGVHD), leukemia-free survival (LFS), overall survival (OS), and relapse were considered. RESULTS: Engraftment occurred in 97% of patients. Forty-two patients were alive at last follow-up, with a 5-year OS rate of 26%. The 5-year probability for TRM, LFS, and relapse was 46%, 25%, and 59%, respectively. Grade ≥ 2 aGVHD occurred in 59% of patients, and chronic GVHD occurred in 32%. In multivariate analysis, diagnosis, interval to relapse after first HSCT > 292 days, aGVHD at first HSCT, complete remission status at second HSCT, use of total-body irradiation at second HSCT, acute GVHD at second HSCT, and use of bone marrow as source of stem cells at second HSCT were associated with better outcome. CONCLUSION: Second HSCT represents an effective therapeutic option for AL patients relapsed after allogeneic HSCT, with a 3-year LFS rate of 52% for the subset of patients who experienced relapse more than 292 days after receiving the first HSCT and who were in remission before receiving the second HSCT.

scholarly journals Characterization of Thy-1 (CDw90) expression in CD34+ acute leukemia

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 60-65 ◽  
Author(s):  
JT Holden ◽  
RB Geller ◽  
DC Farhi ◽  
HK Holland ◽  
LL Stempora ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Acute Leukemia ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Myelogenous Leukemia ◽  
Acute Leukemias ◽  
Hematopoietic Stem

Thy-1 (CDw90) is a phosphatidylinositol-anchored cell surface molecule which, when coexpressed with CD34 in normal human bone marrow, identifies a population of immature cells that includes putative hematopoietic stem cells. To date, the characterization of Thy-1 expression has been confined largely to normal tissues and cell lines. In this study, we evaluated the frequency and intensity of Thy-1 expression as defined by reactivity with the anti-Thy-1 antibody 5E10 in 38 cases of CD34+ acute leukemia (21 acute myelogenous leukemia [AML], 8 chronic myelogenous leukemia [CML] in blast crisis, and 9 acute lymphoblastic leukemia [ALL]). In 34 of 38 cases (89%) the CD34+ cells lacked expression of the Thy-1 antigen. High-density Thy-1 expression was found in 1 case of CML in lymphoid blast crisis, and low- density Thy-1 expression was identified on a portion of the leukemic cells in 2 cases of AML with myelodysplastic features, and 1 case of CML in myeloid blast crisis, suggesting a possible correlation between Thy-1 expression and certain instances of stem cell disorders such as CML and AML with dysplastic features. In contrast, the dissociation of Thy-1 and CD34 expression in the majority of acute leukemias studied suggests that the development of these leukemias occurs at a later stage than the hematopoietic stem cell. Characterization of Thy-1 expression in acute leukemia may eventually provide insights into the origin of the disease. In addition, separation of leukemic blasts from normal stem cells based on Thy-1 expression may prove useful in assessing residual disease, as well as in excluding leukemic blasts from stem cell preparations destined for autologous bone marrow or peripheral stem cell transplantation.

Induced Hematopoietic Differentiation Of Common Marmoset Embryonic Stem Cells By LYL1 Can Give Rise To Hematopoietic Stem Cells Having The Enhanced Bone Marrow Reconstitution Capability

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1192-1192
Author(s):  
Hirotaka Kawano ◽  
Tomotoshi Marumoto ◽  
Takafumi Hiramoto ◽  
Michiyo Okada ◽  
Tomoko Inoue ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Lymphoblastic Leukemia ◽  
Embryonic Stem ◽  
Hematopoietic Differentiation ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Hsc Transplantation

Abstract Hematopoietic stem cell (HSC) transplantation is the most successful cellular therapy for the malignant hematopoietic diseases such as leukemia, and early recovery of host’s hematopoiesis after HSC transplantation has eagerly been expected to reduce the regimen related toxicity for many years. For the establishment of the safer and more efficient cell source for allogeneic or autologous HSC transplantation, HSCs differentiated from embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) that show indefinite proliferation in an undifferentiated state and pluripotency, are considered to be one of the best candidates. Unfortunately, despite many recent efforts, the HSC-specific differentiation from ESCs and iPSCs remains poor [Kaufman, DS et al., 2001][Ledran MH et al., 2008]. In this study, we developed the new method to differentiate HSC from non-human primate ESC/iPSC. It has been reported that common marmoset (CM), a non-human primate, is a suitable experimental animal for the preclinical studies of HSC therapy [Hibino H et al., 1999]. We have been investigated the hematopoietic differentiation of CM ESCs into HSCs, and previously reported that the induction of CD34+ cells having a blood colony forming capacity from CM ESCs were promoted by lentiviral transduction of TAL1 cDNA [Kurita R et al., 2006]. However, those CD34+ cells did not have a bone marrow reconstituting ability in irradiated NOG (NOD/Shi-scid/IL-2Rγnull) mice, suggesting that transduction of TAL1 gene was not sufficient to induce functional HSCs which have self-renewal capability and multipotency. Thus, we tried to find other hematopoietic genes being able to promote hematopoietic differetiation more efficiently than TAL1. We selected 6 genes (LYL1, HOXB4, BMI1, GATA2, c-MYB and LMO2) as candidates for factors that induce the differentiation of ESCs into HSCs, based on the previous study of hematopoietic differentiation from human and mouse ESCs. And CM ESCs (Cj11) lentivirally transduced with the respective candidate gene were processed for embryoid body (EB) formation to induce their differentiation into HSCs for 9 days. We found that lentiviral transduction of LYL1 (lymphoblastic leukemia 1), a basic helix-loop-helix transcription factor, in EBs markedly increased the proportion of cells positive for CD34 (approximately 20% of LYL1-transduced cells). RT-PCR showed that LYL1-transduced EBs expressed various hematopoietic genes, such as TAL1, RUNX1 and c-KIT. To examine whether these CD34+ cells have the ability to differentiate into hematopoietic cells in vitro, we performed colony-forming unit (CFU) assay, and found that CD34+ cells in LYL1-transduced EBs could form multi-lineage blood colonies. Furthermore the number of blood colonies originated from CD34+CD45+ cells in LYL1-transduced EBs was almost the same as that from CD34+CD45+ cells derived from CM bone marrow. These results suggested that enforced expression of LYL1 in CM ESCs promoted the emergence of HSCs by EB formation in vitro. The LYL1 was originally identified as the factor of a chromosomal translocation, resulting in T cell acute lymphoblastic leukemia [Mellentin JD et al., 1989]. The Lyl1-deficient mice display the reduction of B cells and impaired long-term hematopoietic reconstitution capacity [Capron C et al., 2006]. And, transduction of Lyl1 in mouse bone marrow cells induced the increase of HSCs and lymphocytes in vitro and in vivo [Lukov GL et al., 2011]. Therefore we hypothesized that LYL1 may play essential roles in bone marrow reconstitution by HSCs differentiated from CM ESCs. To examine this, we transplanted CD34+ cells derived from LYL1-transduced CM ESCs into bone marrow of sublethally irradiated NOG mice, and found that about 7% of CD45+ cells derived from CM ESCs were detected in peripheral blood (PB) of recipient mice at 8 weeks after transplant (n=4). Although CM CD45+ cells disappeared at 12 weeks after transplant, CD34+ cells (about 3%) were still found in bone marrow at the same time point. Given that TAL1-transduced EBs derived from CM ESCs could not reconstitute bone marrow of irradiated mice at all, LYL1 rather than TAL1 might be a more appropriate transcription factor that can give rise to CD34+ HSCs having the enhanced capability of bone marrow reconstitution from CM ESCs. We are planning to do in vivo study to prove this hypothesis in CM. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Behavior and biocompatibility of rabbit bone marrow mesenchymal stem cells with bacterial cellulose membrane

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4656 ◽  
Author(s):  
Marcello de Alencar Silva ◽  
Yulla Klinger de Carvalho Leite ◽  
Camila Ernanda Sousa de Carvalho ◽  
Matheus Levi Tajra Feitosa ◽  
Michel Muálem de Moraes Alves ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Macrophage Activation ◽  
Cellulose Membrane ◽  
Colony Forming Unit ◽  
Bacterial Cellulose Membrane ◽  
Marrow Mesenchymal Stem Cells ◽  
Rabbit Bone

Background Tissue engineering has been shown to exhibit great potential for the creation of biomaterials capable of developing into functional tissues. Cellular expansion and integration depends on the quality and surface-determinant factors of the scaffold, which are required for successful biological implants. The objective of this research was to characterize and evaluate the in vitro characteristics of rabbit bone marrow mesenchymal stem cells (BM-MSCs) associated with a bacterial cellulose membrane (BCM). We assessed the adhesion, expansion, and integration of the biomaterial as well as its ability to induce macrophage activation. Finally, we evaluated the cytotoxicity and toxicity of the BCM. Methods Samples of rabbit bone marrow were collected. Mesenchymal stem cells were isolated from medullary aspirates to establish fibroblast colony-forming unit assay. Osteogenic, chondrogenic, and adipogenic differentiation was performed. Integration with the BCM was assessed by scanning electron microscopy at 1, 7, and 14 days. Cytotoxicity was assessed via the production of nitric oxide, and BCM toxicity was assessed with the MTT assay; phagocytic activity was also determined. Results The fibroblastoid colony-forming unit (CFU-F) assay showed cells with a fibroblastoid morphology organized into colonies, and distributed across the culture area surface. In the growth curve, two distinct phases, lag and log phase, were observed at 15 days. Multipotentiality of the cells was evident after induction of osteogenic, chondrogenic, and adipogenic lineages. Regarding the BM-MSCs’ bioelectrical integration with the BCM, BM-MSCs were anchored in the BCM in the first 24 h. On day 7 of culture, the cytoplasm was scattered, and on day 14, the cells were fully integrated with the biomaterial. We also observed significant macrophage activation; analysis of the MTT assay and the concentration of nitric oxide revealed no cytotoxicity of the biomaterial. Conclusion The BCM allowed the expansion and biointegration of bone marrow progenitor cells with a stable cytotoxic profile, thus presenting itself as a biomaterial with potential for tissue engineering.

scholarly journals UM171 Regulates the Hematopoietic Differentiation of Human Acquired Aplastic Anemia-Derived Induced Pluripotent Stem Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2500-2500
Author(s):  
Tellechea Maria Florencia ◽  
Flavia S. Donaires ◽  
Tiago C. Silva ◽  
Lilian F. Moreira ◽  
Yordanka Armenteros ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Patient Specific ◽  
Hematopoietic Differentiation ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Induced Pluripotent

Aplastic anemia (AA) is characterized by a hypoplastic bone marrow associated with low peripheral blood counts. In acquired cases, the immune system promotes hematopoietic stem and progenitor cell (HSPC) depletion by the action of several pro-inflammatory Th1 cytokines. The current treatment options for severe cases consist of sibling-matched allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) with anti-thymocyte globulin, cyclosporine, and eltrombopag. However, most patients are not eligible for HSCT and, although about 85% of patients respond to IST with eltrombopag, a proportion of patients eventually relapse, requiring further therapies. Failure to respond adequately to immunosuppression may be attributed to the scarcity of HSPCs at the time of diagnosis. Induced pluripotent stem cells (iPSCs) are potentially an alternative source of patient-specific hematopoietic cells. Patient-specific HSPCs derived from in vitro iPSC differentiation may serve as a tool to study the disease as well as a source of hematopoietic tissue for cell therapies. The pyrimidoindole molecule UM171 induces ex vivo expansion of HSCs of human cord and peripheral blood and bone marrow, but the pathways modulated by this molecule are not well understood. Here we evaluated the hematopoietic differentiation potential of iPSCs obtained from patients with acquired AA. We further determined the effects of UM171 on this differentiation process. First, we derived iPSCs from 3 patients with acquired AA after treatment (1 female; average age, 31 years; 2 partial responders, 1 complete responder) and 3 healthy subjects (3 females; average age, 61 years) and induced differentiation in vitro through the embryoid body system in cell feeder and serum-free medium supplemented with cytokines. The hematopoietic differentiation of healthy-iPSCs yielded 19% ± 8.1% (mean ± SEM) of CD34+cells after 16 days in culture, in contrast with 11% ± 4.9% of CD34+cells obtained from the differentiation of AA-iPSCs, which corresponds to a 1.7-fold reduction in CD34+cell yield. The total number of erythroid and myeloid CFUs was lower in the AA-iPSC group as compared to healthy-iPSCs (12±4.2 vs.24±7.2; respectively; p<0.03). These findings suggest that erythroid-derived AA-iPSC have an intrinsic defect in hematopoietic differentiation. Next, we tested whether UM171 modulated hematopoietic differentiation of AA-iPSCs. We found that UM171 significantly stimulated the differentiation of both healthy and AA-iPSCs. In the healthy-iPSC group, the percentage of CD34+cells was 1.9-fold higher when treated with UM171 compared to controls treated with DMSO (37% ± 7.8% vs.19% ± 8.1%; respectively; p<0.03) and in AA-iPSCs the increase was 3.9-fold (45% ± 11% vs. 11% ± 4.9%; p<0.07). The clonogenic capacity of progenitors to produce erythroid and myeloid colonies also was augmented in both groups in comparison to DMSO (28±11 vs. 23±7.2) for healthy-iPSCs and for AA-iPSCs (23±8.5 vs. 12±4.2, p<0.06). We then investigated the molecular pathways influenced by UM171. The transcriptional profile of differentiated CD34+cells showed that UM171 up-regulated genes involved in early hematopoiesis from mesoderm (BRACHYURY and MIXL1) and primitive streak specification (APELA and APLNR), to hemangioblasts and primitive hematopoietic progenitor commitment (TDGF1, SOX17, and KLF5). We also observed the up-regulation of pro-inflammatory NF-kB activators (MAP4K1, ZAP70, and CARD11) and the anti-inflammatory gene PROCR, a marker of cultured HSCs and an NF-kB inhibitor. This balanced network has been previously suggested to be modulated by UM171 (Chagraoui et. al. Cell Stem Cell 2019). Taken together, our results showed that acquired AA-iPSCs may have intrinsic defects that impair hematopoietic differentiation in vitro. This defect may be atavic to the cell or, alternatively, the consequence of epigenetic changes in erythroid precursors provoked by the immune attack. In addition, our findings demonstrate that UM171 significantly stimulate the hematopoietic differentiation of AA-iPSCs and identified a novel molecular mechanism for UM171 as an enhancer of early hematopoietic development programs. These observations may be valuable for improving the achievement of de novo hematopoietic cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals GATA2 deficiency and human hematopoietic development modeled using induced pluripotent stem cells

2018 ◽  
Vol 2 (23) ◽  
pp. 3553-3565 ◽  
Author(s):  
Moonjung Jung ◽  
Stefan Cordes ◽  
Jizhong Zou ◽  
Shiqin J. Yu ◽  
Xavi Guitart ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Nk Cells ◽  
Pluripotent Stem Cells ◽  
Bone Marrow Failure ◽  
Hematopoietic Differentiation ◽  
Hematopoietic Stem ◽  
Hematopoietic Development ◽  
Gata2 Deficiency ◽  
Induced Pluripotent

Abstract GATA2 deficiency is an inherited or sporadic genetic disorder characterized by distinct cellular deficiency, bone marrow failure, various infections, lymphedema, pulmonary alveolar proteinosis, and predisposition to myeloid malignancies resulting from heterozygous loss-of-function mutations in the GATA2 gene. How heterozygous GATA2 mutations affect human hematopoietic development or cause characteristic cellular deficiency and eventual hypoplastic myelodysplastic syndrome or leukemia is not fully understood. We used induced pluripotent stem cells (iPSCs) to study hematopoietic development in the setting of GATA2 deficiency. We performed hematopoietic differentiation using iPSC derived from patients with GATA2 deficiency and examined their ability to commit to mesoderm, hemogenic endothelial precursors (HEPs), hematopoietic stem progenitor cells, and natural killer (NK) cells. Patient-derived iPSC, either derived from fibroblasts/marrow stromal cells or peripheral blood mononuclear cells, did not show significant defects in committing to mesoderm, HEP, hematopoietic stem progenitor, or NK cells. However, HEP derived from GATA2-mutant iPSC showed impaired maturation toward hematopoietic lineages. Hematopoietic differentiation was nearly abolished from homozygous GATA2 knockout (KO) iPSC lines and markedly reduced in heterozygous KO lines compared with isogenic controls. On the other hand, correction of the mutated GATA2 allele in patient-specific iPSC did not alter hematopoietic development consistently in our model. GATA2 deficiency usually manifests within the first decade of life. Newborn and infant hematopoiesis appears to be grossly intact; therefore, our iPSC model indeed may resemble the disease phenotype, suggesting that other genetic, epigenetic, or environmental factors may contribute to bone marrow failure in these patients following birth. However, heterogeneity of PSC-based models and limitations of in vitro differentiation protocol may limit the possibility to detect subtle cellular phenotypes.

Transplantation of Haplo-Identical Bone Marrow-Derived Mesenchymal Stem Cells Together with Hematopoietic Stem Cells To Promote Engraftment in Children. A Phase I/II Multicenter Study.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2911-2911
Author(s):  
Lynne Margaret van Velzen-Ball ◽  
Katarina Le Blanc ◽  
Arjen C. Lankester ◽  
Helene Roelofs ◽  
Maarten Egeler ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Calf Serum ◽  
Donor Cell ◽  
Patient Characteristics ◽  
Allogeneic Transplantation ◽  
Immune Recovery ◽  
Hematopoietic Stem ◽  
Marrow Mesenchymal Stem Cells

Abstract Graft failure or rejection is an identified problem in haplo-identical or second attempt transplantation. In the bone marrow, mesenchymal stem cells (MSCs) have been identified and shown in animal models to enhance hematopoietic stem cell (HSC) engraftment. Advances in techniques and higher quality culture components have allowed the development of an MSC expansion procedure resulting in sufficient MSCs for clinical application. Adult studies have suggested that co-transplantation of MSCs and HSCs in the HLA-identical setting, is feasible and safe. Here we present the first combined clinical experience within the EBMT MSC expansion consortium with respect to co-transplantation of haplo-identical MSCs in the pediatric allogeneic transplantation setting. Six weeks before the SCT, 50 cc of bone marrow are sampled under sterile conditions. Density gradient-separated MNCs are plated into tissue culture flasks in low-glucose DMEM supplemented with 10% fetal calf serum and incubated at 370C with 5% CO2. At 70% confluence, the cells are trypsinized and re-plated at 4x103 cells/ cm2 until the target dose of 1–2 x106/kg recipient body weight is obtained. Enrichment and expansion of MSCs is performed under GMP conditions in nationally accredited laboratories. MSCs (either fresh or cryopreserved) are administered i.v. 4 hours before infusion of donor HSCs. To date 4 children have undergone co-transplantation. Patient characteristics are summarized in the table. All toxicities associated with the procedure were documented, as were the engraftment kinetics and immune recovery. The study was carried out with approval of the respective local ethical committees. The data indicate that expansion and co-transplantation of MSCs is feasible and well tolerated. While the study is ongoing initial engraftment and immune recovery data (compared to historical data) is encouraging and to date there have been no episodes of graft rejection or severe adverse events related to this treatment. Patient characteristics Patient demographics HSC characteristics MSC characteristics UPN Gender Age Diagnosis Donor CD34 dose (106/kg) Donor Cell dose (106/kg) 1 M 15 ANLL mother-haplo 16 mother 1.5 2 M 2 XLPD father-haplo 20 father 1.9 3 M 2 XLPD father-haplo 18.7 father 1.56 4 M 8 SAA URD (2 loci mismatched) 2.65 mother 1.0

Overexpression of NF-E2 In Vivo Causes Thrombocytosis and Acute Leukemia: A Murine Model of Myeloproliferative Neoplasms.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 961-961
Author(s):  
Albert Gruender ◽  
Kai Kaufmann ◽  
Tobias Hadlich ◽  
Thomas Günther ◽  
Roland Schüle ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Transcription Factor ◽  
Transgenic Mice ◽  
Acute Leukemia ◽  
Myeloproliferative Neoplasms ◽  
Transgenic Animals ◽  
Spleen Weight ◽  
Hematopoietic Stem

Abstract Abstract 961 The transcription factor nuclear factor erythroid-2 (NF-E2) is expressed in hematopoietic stem cells as well as in myeloid, erythroid and megakaryocytic precursors. NF-E2 deficient mice display marked anemia at birth and die perinatally due to thrombopenia, demonstrating an essential role for NF-E2 in both in erythropoiesis and platelet formation. We have previously shown that NF-E2 is overexpressed in the vast majority of patients with Myeloproliferative Neoplasms (MPNs). However, the effect of augmented transcription factor activity has not been studied in vivo. We therefore engineered two independent transgenic mouse lines expressing human NF-E2 under the control of the vav-Promoter, which has previously been shown to direct transgene expression in hematopoietic stem cells as well as in precursor cells of all lineages. The two founder lines differed in the degree of NF-E2 overexpression displayed. While one line showed moderate overexpression (2 – 5-fold), the other line expressed human NF-E2 between 10 and 100-fold above the murine counterpart. Both lines paralleled observations in PV patients, where a wide range of NF-E2 overexpression was noted (median overexpression, 7-fold; range 2-fold to 40-fold; n = 59). The two founder lines show overlapping but distinct phenotypes. In both strains. moderately overexpressing NF-E2 transgenic mice (2 – 10-fold) invariably develop thrombocytosis with a latency of 14 months. In addition, megakaryocyte colony formation in the bone marrow is drastically increased. In contrast, thrombocytosis is not observed in the markedly overexpressing NF-E2 transgenic mice (above 20-fold). A similar inverse correlation between the degree of NF-E2 overexpression and platelet numbers was observed in MPN patients. In both strains, Epo-independent colony formation, a pathognomonic feature of polycythemia vera, is significantly increased in NF-E2 transgenic animals. Bone marrow histopathology shows findings characteristically seen in MPNs, including the presence of increased megakaryopoiesis with cytologically abnormal forms, often in clusters. Both NF-E2 transgenic strains display significantly increased mortality. Upon autopsy, between 15 and 20% of mice in both strains present with major gastrointestinal bleeding in conjunction with splenic atrophy. Spleen weight is reduced by over 50% (Transgenic mice: 49 +/-15 mg, wild type littermates 103 +/- 30 mg; p < 0.001, n = 8 each). One third of the remaining mice show moderate to marked splenomegaly (2 – 27 fold increase in spleen weight; mean: 434 mg, range: 124 – 2700 mg; p < 0.001 vs. wt littermates, n = 12). Histopathological examination of all spleens revealed mild to moderately expanded red pulp with increased numbers of iron containing histiocytes. This observation indicates increased red cell destruction and may explain the fact that neither hematocrit nor hemoglobin are elevated in NF-E2 transgenic animals. At 18 months of age, one mouse developed acute leukemia, which is currently being phenotyped. In summary, in a murine model moderate NF-E2 overexpression causes a phenotype resembling Essential Thrombocythemia. In addition, our preliminary data indicate that NF-E2 overexpression may predispose to the development of acute leukemia. Disclosures: No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document