Expression Cloning of Genes Enabling Erythropoietin -Independent Erythropoiesis in Vitro.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3608-3608
Author(s):  
Tomoko Yokoo ◽  
Ryo Kurita ◽  
Atsushi Takahashi ◽  
Michiyo Okada ◽  
Hirotaka Kawano ◽  
...  

Abstract Abstract 3608 Poster Board III-544 Erythropoietin (EPO) is essential during both ontogeny and the course of erythropoiesis. In primitive (yolk sac) erythropoiesis, however, the role of EPO is not fully understood. Elucidation of such role in primitive erythropoiesis would be very helpful for the development of ex vivo red blood cell expansion system from embryonic stem (ES) cells. Recently, we reported the establishment of the ex vivo induction of hematopoietic stem cells from common marmoset ES cells using lentiviral-Tal1/Scl gene transfer in the absence of any stromal cells (Stem Cells 24: 2014-2022, 2006). This method should also be applicable to both of human ES cells and induced pluripotential stem (iPS) cells, but the efficiency will be very critical for its clinical application. In the present study, we proceed further to find out unknown factors which accelerate ex vivo proliferation and differentiation of erythroid cells, constructed the human fetal liver cDNA expression lentiviral library (Mol Cell Biochem 319: 181-187, 2008) and screened for cDNAs which confer EPO independency to an EPO-dependent cell line, UT-7/Epo ( Blood 82: 456-464, 1993). Among twenty-two candidate genes cloned after screening of 6×10∧5 cDNA, we particularly focused on two full-length genes, ribosomal protein L11 (RPL11) and retinol dehydrogenase 11 (RDH11). Two candidate gene-transduced-UT-7/Epo cells, respectively named LV-RPL11 and LV-RDH11, showed complete EPO-independent survival and proliferation, increased expression of fetal γ-globin, and decreased expression of adult β-globin compared with parental UT-7/Epo cells in the presence of EPO. Cell cycle and apoptosis analyses showed decreased apoptotic cell death and increased S/G2/M cells in LV-RPL11 and LV-RDH11 cells compared with UT-7/Epo cells in the absence of Epo. Moreover, STAT5 phosphorylation and upregulation of its target genes, c-Myc, cyclin D and Pim, were observed in LV-RPL11, LV-RDH11 cells in the absence of EPO. In conclusion, the findings suggest that RPL11 and RDH11 play a role in EPO-independent erythropoiesis and might be applicable to ex vivo expansion of red blood cells from ES/iPS cells. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4731-4731
Author(s):  
Hai Wang ◽  
Yadong Yang ◽  
Hongzhu QU ◽  
Xiuyan Ruan ◽  
Zhaojun Zhang ◽  
...  

Abstract Abstract 4731 FOX (Forkhead box) proteins are a family of transcription factors that emerged as playing an important role in the embryonic development, cell cycle, carbohydrate and fatty acid metabolism and immune response. It was found that FOXO3A (also known as FOXO3) involved in erythroid differentiation, yet the mechanism for regulating hematopoietic stem cells (HSCs) differentiation is unknown. We analyzed the dynamics of genome-wide transcriptome (mRNA-Seq) of human undifferentiated embryonic stem cells (HESC), erythroid cells derived from ES cells (ESER), human fetal erythroid liver cells (FLER) and peripheral CD34+derived erythroid cells (PBER) using high throughput sequencing technology. The transcriptome analysis showed that FOXO3 was barely expression in HESC while was observably up-regulated in ESER. However, FOXO3 was down-regulated in FLER and PBER compare with ESER, the erythroid cells at early developmental stage. We presumed that FOXO3 plays an important role in primitive erythropoiesis and built up the interactions network in which FOXO3 acts as a central node by Gene Ontology (GO), correlation analysis and Ingenuity Pathways Analysis (IPA). In addition, we analyzed the profiles of histone methylation in the four types of cells by ChIP-Seq to study the chromatin conformation in the vicinity of FOXO3. More histone 3 lysine 4 (H3K4) trimethylation was found near the promoter region of FOXO3 in ESER compared with the other cells, which is coincided with the mRNA-seq results. We performed a series of experiment to identify the roles of FOXO3 in regulating erythroid differentiation. The results showed that the expression level of ε and γ globin were up-regulated in FOXO3-over-expressed 293T and Hela cells and the expression level of FOXO1 and CAT in predicted network were increased by quantitative real-time PCR detection. In addition, when FOXO3 knocked down in K562 cells, the expression level of ε and γ globin were down-regulated. The expression level of CAT, BCL2L1 and other factors in predicted network, were also decreased. These results indicate FOXO3 plays an important role in globin expression and identify the credibility of our predicted networks in which FOXO3 acts as a central node. FOXO3 binding sites (GTAAACA or ATAAACA) were predicted on the upstream of CAT and BCL2L1. We are trying to prove CAT or BCL2L1 is a direct FOXO3 target in vitro and in vivo. In conclusion, we have demonstrated FOXO3 plays a key role in erythroid differentiation and globin expression. We will further determine the enriched profiles of FOXO3 by ChIP-seq in HESC, ESER, FLER and PBER to find more targets of FOXO3. Since the zebrafish is a powerful model system for investigating vertebrate hematopoiesis. We will identify the role of Foxo3b, the homologous gene of human FOXO3, in erythroid differentiation and study the dynamic transcriptomes of Foxo3b morphants in zebrafish. We are trying to make a whole picture to elaborate the molecular mechanism of FOXO3 involved in regulation of erythroid differentiation. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1186-1186
Author(s):  
Azadeh Zahabi ◽  
Tatsuya Morishima ◽  
Andri Pramono ◽  
Dan Lan ◽  
Lothar Kanz ◽  
...  

Abstract Understanding the molecular mechanisms underlying hematopoietic differentiation of embryonic stem (ES) cells may help to ascertain the optimal conditions for the production of hematopoietic cells as a source for transplantation or experimental use. Previously, we found that patients with congenital amegakaryocytic thrombocytopenia (CAMT), who develop pancytopenia early after birth, harbor mutations within the thrombopoietin (TPO) receptor, c-mpl. This knowledge, together with observations in vitro and in animal models in vivo, suggests that TPO/c-mpl signaling promotes early hematopoiesis. However, the downstream mechanisms underlying TPO signaling are not fully elucidated. Here, we describe for the first time a direct connection between the TPO and bone morphogenetic protein 4 (BMP4) signaling pathways in the hematopoietic fate decision of ES cells. BMP4 is a classical morphogen and a well-known inducer of early hematopoietic differentiation of ES cells. Treatment of ES cells with TPO induced the autocrine production of BMP4 by ES cells with concomitant upregulation of the BMP receptor, BMPR1A, phosphorylation of Smad1, 5, and 8 and activation of the specific target genes, Id1, 2, and 3, and Msx1 and 2. This was mediated by TPO-dependent binding of the HIF-1α transcription factor to the BMP4 gene promoter, resulting in further activation of the BMP4-autoregulatory loop. Treatment of ES cells with the BMP antagonist noggin substantially reduced TPO-dependent hematopoietic differentiation of ES cell. Taken together, our findings contribute to the understanding the mechanisms of hematopoietic differentiaiton of ES cells and might help to establish new methods for the efficient production of hematopoietic stem cells in vitro. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4575-4575
Author(s):  
Philippe Garrigou ◽  
Jean-Francois Mayol ◽  
Catherine Mouret ◽  
Christophe Delaunay ◽  
Michel Drouet ◽  
...  

Abstract Abstract 4575 Mesenchymal Stem cells (MSC) are an important radiosensitive component of the so called hematopoietic stem cell niche. Importantly this supportive microenvironment influences the stem cell repopulation capacity as well as the quiescent/non proliferative state of hematopoietic cells. Senescence is considered as a major process in MSC response following irradiation. However, other studies have reported in mice the reduction of the pool of bone marrow mesenchymal stem/progenitor cells following TBI independently of senescence. An altered osteoblastic differentiation was pointed out in these studies. Furthermore, MSC have been shown to be involved in the repair of ionizing radiation damage of distant epithelial sites which requires adherence genes mitigation. The aim of this study was to clarify some of these points using an in vitro model of irradiation and short term culture. Briefly, confluent human BM-MSC were irradiated at the dose of 2.5 Gy (dose rate: 95 cGy.min-1) and immediately put into culture (Minimum essential medium supplemented with 10% FCS and 10 μg/ml of ciprofloxacin, penicillin and streptomycin). Six, 12, 24, 48 and 72 hours after irradiation, cells were harvested and lysed. Total RNAs were purified using the automatic Qiacube system (Qiagen,Courtaboeuf, France) and processed on DNA microarray scanner (Agilent technologies Inc.) according to supplier's recommendations. Data were analyzed with GeneSpring GX Expresion Analysis software version 10.0 (Agilent) in order to identify the transduction pathways involved. No apoptosis was observed during this short term incubation. Among other genes we identified plasminogen activator inhibitor 1 (PAI-1) as a factor highly upregulated after irradiation, in addition to CD151. This is in accordance with MSC response to nutrient-poor, hypoxic stress environment (Copland et al, Stem cells 2009). As MSC are radiosensitive cells, this may indicate that PAI impacts MSC survival through the mitigation of their adhesiveness to surrounding matrices. As PAI-1 is an important factor involved in the balance of blood coagulation and fibrinolysis as well as in the regulation of angiogenesis, one may speculate the consequences of PAI-1 release from MSC on blood homeostasis. Work is going on to describe the main response target genes. This could allow us to identify therapeutic strategies based on ex-vivo or in vivo manipulation of MSC in a purpose of tissue remodelling. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1265-1275 ◽  
Author(s):  
Abby L. Olsen ◽  
David L. Stachura ◽  
Mitchell J. Weiss

Embryonic stem (ES) cells exhibit the remarkable capacity to become virtually any differentiated tissue upon appropriate manipulation in culture, a property that has been beneficial for studies of hematopoiesis. Until recently, the majority of this work used murine ES cells for basic research to elucidate fundamental properties of blood-cell development and establish methods to derive specific mature lineages. Now, the advent of human ES cells sets the stage for more applied pursuits to generate transplantable cells for treating blood disorders. Current efforts are directed toward adapting in vitro hematopoietic differentiation methods developed for murine ES cells to human lines, identifying the key interspecies differences in biologic properties of ES cells, and generating ES cell-derived hematopoietic stem cells that are competent to repopulate adult hosts. The ultimate medical goal is to create patient-specific and generic ES cell lines that can be expanded in vitro, genetically altered, and differentiated into cell types that can be used to treat hematopoietic diseases.


Blood ◽  
1996 ◽  
Vol 87 (7) ◽  
pp. 2740-2749 ◽  
Author(s):  
CD Helgason ◽  
G Sauvageau ◽  
HJ Lawrence ◽  
C Largman ◽  
RK Humphries

Little is known about the molecular mechanisms controlling primitive hematopoietic stem cells, especially during embryogenesis. Homeobox genes encode a family of transcription factors that have gained increasing attention as master regulators of developmental processes and recently have been implicated in the differentiation and proliferation of hematopoietic cells. Several Hox homeobox genes are now known to be differentially expressed in various subpopulations of human hematopoietic cells and one such gene, HOXB4, has recently been shown to positively determine the proliferative potential of primitive murine bone marrow cells, including cells with long-term repopulating ability. To determine if this gene might influence hematopoiesis at the earliest stages of development, embryonic stem (ES) cells were genetically modified by retroviral gene transfer to overexpress HOXB4 and the effect on their in vitro differentiation was examined. HOXB4 overexpression significantly increased the number of progenitors of mixed erythroid/myeloid colonies and definitive, but not primitive, erythroid colonies derived from embryoid bodies (EBs) at various stages after induction of differentiation. There appeared to be no significant effect on the generation of granulocytic or monocytic progenitors, nor on the efficiency of EB formation or growth rate. Analysis of mRNA from EBs derived from HOXB4-transduced ES cells on different days of primary differentiation showed a significant increase in adult beta-globin expression, with no detectable effect on GATA-1 or embryonic globin (beta H-1). Thus, HOXB4 enhances the erythropoietic, and possibly more primitive, hematopoietic differentiative potential of ES cells. These results provide new evidence implicating Hox genes in the control of very early stages in the development of the hematopoietic system and highlight the utility of the ES model for gaining insights into the molecular genetic regulation of differentiation and proliferation events.


2017 ◽  
Vol 37 (7) ◽  
pp. 647-660 ◽  
Author(s):  
Saradaprasan Muduli ◽  
Li-Hua Chen ◽  
Meng-Pei Li ◽  
Zhao-wen Heish ◽  
Cheng-Hui Liu ◽  
...  

Abstract The physical characteristics of cell culture materials, such as their elasticity, affect stem cell fate with respect to cell proliferation and differentiation. We systematically investigated the morphologies and characteristics of several stem cell types, including human amniotic-derived stem cells, human hematopoietic stem cells, human induced pluripotent stem (iPS) cells, and embryonic stem (ES) cells on poly(vinyl alcohol) (PVA) hydrogels immobilized with and without extracellular matrix-derived oligopeptide. Human ES cells did not adhere well to soft PVA hydrogels immobilized with oligovitronectin, whereas they did adhere well to PVA hydrogel dishes with elasticities greater than 15 kPa. These results indicate that biomaterials such as PVA hydrogels should be designed to possess minimum elasticity to facilitate human ES cell attachment. PVA hydrogels immobilized with and without extracellular matrix-derived oligopeptides are excellent candidates of cell culture biomaterials for investigations into how cell culture biomaterial elasticity affects stem cell culture and differentiation.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4320-4320
Author(s):  
Yukinori Nakamura ◽  
Toshiaki Yujiri ◽  
Ryouhei Nawata ◽  
Kozo Tagami ◽  
Yukio Tanizawa

Abstract BCR-ABL oncogene, the molecular hallmark of chronic myelogenous leukemia, arises in a primitive hematopoietic stem cell that has the capacity for both differentiation and self-renewal. Its product, Bcr-Abl protein, has been shown to activate STAT3 and to promote self-renewal in ES cells, even in the absence of leukemia inhibitory factor (LIF). MEK kinase 1 (MEKK1) is a 196-kDa mitogen-activated protein kinase (MAPK) kinase kinase involved in Bcr-Abl signal transduction (Oncogene22:7774, 2003). To investigate the role of MEKK1 in Bcr-Abl-induced transformation of ES cells, p210 Bcr-Abl was stably transfected into wild type (WT+p210) and MEKK1−/− (MEKK1−/−+p210) ES cells. Bcr-Abl enhanced both MEKK1 expression and activation in ES cells, as it does in other Bcr-Abl-transformed cells. In the absence of LIF, WT+p210 cells showed constitutive STAT3 activation and formed compact colonies having strong alkaline phosphatase activity, a characteristic phenotype of undifferentiated ES cells. MEKK1−/−+p210 cells, by contrast, showed less STAT3 activity than WT+p210 cells and formed large, flattened colonies having weak alkaline phosphatase activity, a phenotype of differentiated ES cells. These results indicate that MEKK1 plays an essential role in Bcr-Abl-induced STAT3 activation and in the capacity for LIF-independent self-renewal, and may thus be involved in Bcr-Abl-mediated leukemogenesis in stem cells.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3568-3568
Author(s):  
Mattias Magnusson ◽  
Melissa Romero ◽  
Sacha Prashad ◽  
Ben Van Handel ◽  
Suvi Aivio ◽  
...  

Abstract Expansion of human hematopoietic stem cells (HSCs) ex vivo has been difficult due to limited understanding of their growth requirements and the molecular complexity of their natural microenvironments. To mimic the niches in which human HSCs normally develop and expand during ontogeny, we have derived two unique types of stromal niche cells from the first trimester human placenta and the fetal liver. These lines either support maintenance of multipotential progenitors in culture, or promote differentiation into macrophages. Impressively, the supportive lines facilitate over 50,000-fold expansion of the most immature human HSCs/progenitors (CD34+CD38-Thy1+) during 8-week culture supplemented with minimal cytokines FLT3L, SCF and TPO, whereas the cells cultured on non-supportive stroma or without stroma under the same conditions differentiated within 2 weeks. As the supportive stroma lines also facilitate differentiation of human hematopoietic progenitors into myeloid, erythroid and B-lymphoid lineages, we were able to show that the expanded progenitors preserved full multipotentiality during long-term culture ex vivo. Furthermore, our findings indicate that the supportive stroma lines also direct differentiation of human embryonic stem cells (hESC) into hematopoietic progenitor cells (CD45+CD34+) that generate multiple types of myeloerythroid colonies. These data imply that the unique supportive niche cells can both support hematopoietic specification and sustain a multilineage hematopoietic hierarchy in culture over several weeks. Strikingly, the supportive effect from the unique stromal cells was dominant over the differentiation effect from the non-supportive lines. Even supernatant from the supportive lines was able to partially protect the progenitors that were cultured on the non-supportive lines, whereas mixing of the two types of stroma resulted in sustained preservation of the multipotential progenitors. These results indicate that the supportive stroma cells possess both secreted and surface bound molecules that protect multipotentiality of HSCs. Global gene expression analysis revealed that the supportive stroma lines from both the placenta and the fetal liver were almost identical (r=0.99) and very different from the non-supportive lines that promote differentiation (r=0.34), implying that they represent two distinct niche cell types. Interestingly, the non-supportive lines express known mesenchymal markers such as (CD73, CD44 and CD166), whereas the identity of the supportive cells is less obvious. In summary, we have identified unique human stromal niche cells that may be critical components of the HSC niches in the placenta and the fetal liver. Molecular characterization of these stroma lines may enable us to define key mechanisms that govern the multipotentiality of HSCs.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 889-889
Author(s):  
ZacK Z. Wang ◽  
Hao Bai ◽  
Melanie Arzigian ◽  
Yong-Xing Gao ◽  
Wen-Shu Wu

Abstract Pluripotent stem cells derived from patients, including embryonic stem (ES) cells and “induced pluripotent stem” (iPS) cells, are a promising area of regenerative medical research. A major roadblock toward human clinical therapies using ES cells or iPS cells is to define the factors that direct ES cell differentiation into lineage specific cells. We previously established a simple and efficient human embryonic stem cell (hESC) differentiation system to generate CD34+/CD31+ progenitor cells that gave rise to hematopoietic and endothelial cells (Nat Biotech.25:317, 2007). To advance potential clinical application and to define the effects of growth factors on hematopoietic and vascular differentiation, we assessed hESC differentiation on human feeder cells in serum-free condition without intermediate embryoid body (EB) formation. We investigated the roles of BMPs, TGFbeta, VEGF, and FGF2 in directing hESC differentiation. Growth factors were added into culture at different time points to test their stage specific roles. Our study demonstrated that BMP proteins, including BMP2, BMP4, and BMP7, but not BMP9, had synergic effects to VEGF and FGF-2 on hESC differentiation to CD34+/CD31+ progenitor cells. BMP4 was essential to initial CD34+/CD31+ cell development, whereas VEGF and FGF2 promoted the differentiation in later stage, suggesting the sequential roles of BMP4, VEGF and FGF2 in directing hESC differentiation to CD34+/CD31+ progenitor cells. TGFbeta or activin promoted hESC differentiation into CD34+/CD31− cells that were unable to give rise to hematopoietic, endothelial, and smooth muscle cells. Furthermore, TGFbeta or activin activated Smad2/3 signaling, and suppressed BMP4-induced CD34+/CD31+ cells. Microarray analysis revealed that BMP4-induced CD34+ cells expressed hematopoietic, endothelial and smooth muscle genes, including GATA2, gamma globins, VE-Cad, KDR, CD31, Tie2, and aortic smooth muscle actin, whereas TGFbeta-induced CD34+ cells expressed pluripotent markers and endoderm markers, including Oct3/4, Sox2, and Nanog, HHEX, GATA6, and FoxA2. Both canonical BMP signaling (Smad1/5/8-dependent) and non-canonical BMP signaling (p38 MAPK and p42 ERK pathway) were activated by BMP4 in hESCs. Dorsomorphin specifically inhibited BMP4-mediated phosphorylation of Smad1/5/8, and blocked hESC differentiation into CD34+/CD31+ cells. In summary, BMPs and TGFbeta regulate distinct populations of CD34+ cells in hESCs. BMP-Smad1/5/8 pathway is critical for hematopoietic and vascular progenitor development.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4544-4544
Author(s):  
Ching-Tien Peng

Abstract Abstract 4544 Bone marrow-derived mesenchymal stem cells (BMMSCs) have been found to enhance engraftment of hematopoietic stem cell transplantation (HSCT), plus show effect against graft-versus host disease (GVHD) because of their immunosuppressive properties. However, harvesting these cells is an invasive and painful procedure. To substitute BMMSCs from alternative sources is necessary. We intravenously infused ex vivo-expanded third-party umbilical cord-derived mesenchymal stem cells (UCMSCs) obtained from a bank 8 times in 3 patients who developed severe, steroid-resistant acute GVHD after allogeneic HSCT. The acute GVHD improved with each infusion of UCMSCs. Besides, after cotransplantation of cord blood and UCMSCs in 5 patients, we found UCMSCs enhanced absolute neutrophil counts and platelet counts recovery. No adverse effects after UCMSCs infusions were noted. We also found that UCMSCs had superior proliferative potential and greater immunosuppressive effects than BMMSCs in vitro. This is the first report of UCMSCs in human clinical application. These findings suggest UCMSCs are effective in treating aGVHD and can enhance hematopoiesis after HSCT. Considering that they are not only easy to obtain but also proliferate rapidly, UCMSCs would be the ideal candidate for cell-based therapy, especially for diseases associated with immune responses because of their immunosuppressive effects. Disclosures: No relevant conflicts of interest to declare.


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