Feugier, P, Li, N, Jo, DY, Shieh, JH, MacKenzie, KL, Lesesve, JF et al. Osteopetrotic mouse stroma with thrombopoietin, c-kit ligand, and flk-2 ligand supports long-term mobilized CD34+ hematopoiesis in vitro. Stem Cells Dev 14: 505-516
James Ewing Laboratory of Developmental Hematopoiesis, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. Stem Cells and Development
(Impact Factor: 3.73).
11/2005; 14(5):505-16. DOI: 10.1089/scd.2005.14.505
OP-9 cells are stromal cells derived from macrophage colony-stimulating factor (M-CSF)-deficient osteopetrotic mice. To evaluate the OP-9 capability to sustain long-term hematopoiesis, we reported the expansion of granulocyte colony-stimulating factor (G-CSF)-mobilized human peripheral blood (PB) CD34(+) cells in co-culture with murine OP-9 and MS-5 stromal cells, either transfected with various combinations of adenovectors (Ad) expressing c-kit ligand (KL) (either soluble or transmembrane form), thrombopoietin (TPO), flt-3/flk2 ligand (FL), and granulocyte-macrophage (GM)-CSF or with weekly addition of these cytokines. Expression of TPO as well as association of TPO, FL, and KL increased progenitor cell and week-6 cobblestone area forming cell (CAFC) production in all stromal co-cultures. Similar progenitor expansion was obtained by weekly addition of soluble cytokine. Five weeks of co-culture with OP9 and TPO, FL + KL resulted in the greatest expansion of progenitor cells and week-6 CAFC as measured by secondary assay on MS-5. In contrast to MS-5 and TPO or TPO + FL + KL cultures where hematopoiesis declined by week 4, progenitor as well as week-6 CAFC expansion continued for over 3 months in TPO + FL + KL OP9 cocultures. This was associated with decrease of CD14(+) macrophage production. The addition of human macrophage (M)-CSF or CD14(+) cells to the co-culture decrease progenitor and stem cell expansion; however, murine M-CSF to OP-9 co-cultures did not decrease progenitor expansion. High levels of stromal-derived factor-1 (SDF-1) production by MS-5 and low or absent production by OP-9 may account for stem cell adhesion and CAFC formation in the former cultures and the predominance of stem and progenitor cells in the nonadherent fraction in the latter cultures.
Available from: Edo Vellenga
- "For example, cytokines that activate STAT5 in the most immature human hematopoietic stem compartment include SCF7 and TPO.8 These cytokines have been shown to promote long-term hematopoiesis in vitro,9 and hypersensitivity to TPO in Lnk−/− mice resulted in elevated stem cell self-renewal, which coincided with increased levels of STAT5 activity.10 Within the erythroid compartment, STAT5 is activated by EPO,11 where STAT5 fulfills an important anti-apoptotic role by upregulating Bcl-Xl,12-15 although a more direct role in initiating erythroid commitment might exist as well.16-18 "
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ABSTRACT: The level of transcription factor activity critically regulates cell fate decisions such as hematopoietic stem cell self-renewal and differentiation. The balance between hematopoietic stem cell self-renewal and differentiation needs to be tightly controlled, as a shift toward differentiation might exhaust the stem cell pool, while a shift toward self-renewal might mark the onset of leukemic transformation. A number of transcription factors have been proposed to be critically involved in governing stem cell fate and lineage commitment, such as Hox transcription factors, c-Myc, Notch1, β-catenin, C/ebpα, Pu.1 and STAT5. It is therefore no surprise that dysregulation of these transcription factors can also contribute to the development of leukemias. This review will discuss the role of STAT5 in both normal and leukemic hematopoietic stem cells as well as mechanisms by which STAT5 might contribute to the development of human leukemias.
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ABSTRACT: Murine embryonic stem cells (mESC) readily form embryoid bodies (EBs) that exhibit hematopoietic differentiation. Methods based on EB formation or ESC coculture with murine bone marrow stromal cell lines have revealed pathways of both primitive and definitive hematopoietic differentiation progressing from primitive mesoderm via hemangioblasts to endothelium and hematopoietic stem and progenitor cells. The addition of specific hematopoietic growth factors and morphogens to these cultures enhances the generation of neutrophils, macrophages, megakaryocyte/platelets, and hemoglobinized mature red cells. In addition, selective culture systems have been developed to support differentiation into mature T lymphocytes, natural killer cells, B cells, and dendritic cells. In most cases, culture systems have been developed that support equivalent differentiation of various human ESC (hESC). The major obstacle to translation of ESC hematopoietic cultures to clinical relevance has been the general inability to produce hematopoietic stem cells (HSC) that can engraft adult, irradiated recipients. In this context, the pattern of ES hematopoietic development mirrors the yolk sac phase of hematopoiesis that precedes the appearance of engraftable HSC in the aorta-gonad-mesonephros region. Genetic manipulation of mESC hematopoietic progeny by upregulation of HOXB4 or STAT5 has led to greatly enhanced long- or short-term multilineage hematopoietic engraftment, suggesting that genetic or epigenetic manipulation of these pathways may lead to functional HSC generation from hESC.
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ABSTRACT: The purpose of the study was to determine whether hematopoietic stem cell (HSCs) mobilization can regulate early diabetic retinopathy in mice.
Mice were divided into four groups: control group, normal mice HSC-mobilized group, diabetic mice control group and diabetic mice HSC-mobilized group. Murine stem cell growth factor (SCF) and recombined human granulocyte colony stimulating factor (rhG-csf) were administered to the mice with diabetes and without diabetes for continuous 5 days to induce autologous HSCs mobilization, and subcutaneous injection of physiological saline was used as control. The changes associated with autologous HSCs mobilization were characterized using flow cytometry, Immunohistochemistry and semiquantitative RT-PCR. Evans blue quantitative test was used to measure the breakdown level of blood-retina barrier.
HSCs were marked by CD34-/low and Sca1+ in this study. The acceleration of endothelial cell regeneration was observed. A decrease of VEGF expression due to autologous stem cell mobilization was found. HSCs could increase the content of VEGFR-2 in mouse retina and significantly downregulated the expression of VEGF and ang-2 in diabetic mice.
The experiment suggest that autologous HSCs mobilization can be approach of therapeutic vascular reconstruction and functional restoration of blood-retina barrier in mice.
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