scholarly journals Steel factor coordinately regulates the molecular signature and biologic function of hematopoietic stem cells

Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 560-567 ◽  
Author(s):  
David G. Kent ◽  
Brad J. Dykstra ◽  
Jay Cheyne ◽  
Elaine Ma ◽  
Connie J. Eaves
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Molecular Mechanisms ◽  
Molecular Signature ◽  
Hematopoietic Stem ◽  
Steel Factor ◽  
Biologic Function

Abstract Hematopoietic stem cells (HSCs) regenerated in vivo display sustained differences in their self-renewal and differentiation activities. Variations in Steel factor (SF) signaling are known to affect these functions in vitro, but the cellular and molecular mechanisms involved are not understood. To address these issues, we evaluated highly purified HSCs maintained in single-cell serum-free cultures containing 20 ng/mL IL-11 plus 1, 10, or 300 ng/mL SF. Under all conditions, more than 99% of the cells traversed a first cell cycle with similar kinetics. After 8 hours in the 10 or 300 ng/mL SF conditions, the frequency of HSCs remained unchanged. However, in the next 8 hours (ie, 6 hours before any cell divided), HSC integrity was sustained only in the 300 ng/mL SF cultures. The cells in these cultures also contained significantly higher levels of Bmi1, Lnk, and Ezh2 transcripts but not of several other regulators. Assessment of 21 first division progeny pairs further showed that only those generated in 300 ng/mL SF cultures contained HSCs and pairs of progeny with similar differentiation programs were not observed. Thus, SF signaling intensity can directly and coordinately alter the transcription factor profile and long-term repopulating ability of quiescent HSCs before their first division.

Strategies to Protect Hematopoietic Stem Cells from Culture-Induced Stress Conditions

2020 ◽  
Vol 15 ◽  
Author(s):  
Fatima Aerts-Kaya
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
Stress Conditions ◽  
Stress Factors ◽  
Hematopoietic Stem ◽  
Induced Stress

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.

scholarly journals The chemokine GROβ mobilizes early hematopoietic stem cells characterized by enhanced homing and engraftment

Blood ◽  
2007 ◽  
Vol 110 (3) ◽  
pp. 860-869 ◽  
Author(s):  
Seiji Fukuda ◽  
Huimin Bian ◽  
Andrew G. King ◽  
Louis M. Pelus
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Hematopoietic Stem ◽  
Platelet Recovery ◽  
And Function ◽  
Stimulating Factor ◽  
Cxcr4 Axis

Abstract Mobilized peripheral blood hematopoietic stem cells (PBSCs) demonstrate accelerated engraftment compared with bone marrow; however, mechanisms responsible for enhanced engraftment remain unknown. PBSCs mobilized by GROβ (GROβΔ4/CXCL2Δ4) or the combination of GROβΔ4 plus granulocyte colony-stimulating factor (G-CSF) restore neutrophil and platelet recovery faster than G-CSF–mobilized PBSCs. To determine mechanisms responsible for faster hematopoietic recovery, we characterized immunophenotype and function of the GROβ-mobilized grafts. PBSCs mobilized by GROβΔ4 alone or with G-CSF contained significantly more Sca-1+-c-kit+-lineage− (SKL) cells and more primitive CD34−-SKL cells compared with cells mobilized by G-CSF and demonstrated superior competitive long-term repopulation activity, which continued to increase in secondary and tertiary recipients. GROβΔ4-mobilized SKL cells adhered better to VCAM-1+ endothelial cells compared with G-CSF–mobilized cells. GROβΔ4-mobilized PBSCs did not migrate well to the chemokine stromal derived factor (SDF)-1α in vitro that was associated with higher CD26 expression. However, GROβΔ4-mobilized SKL and c-Kit+ lineage− (KL) cells homed more efficiently to marrow in vivo, which was not affected by selective CXCR4 and CD26 antagonists. These data suggest that GROβΔ4-mobilized PBSCs are superior in reconstituting long-term hematopoiesis, which results from differential mobilization of early stem cells with enhanced homing and long-term repopulating capacity. In addition, homing and engraftment of GROβΔ4-mobilized cells is less dependent on the SDF-1α/CXCR4 axis.

Hematopoietic stem cells express Tie-2 receptor in the murine fetal liver

Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3757-3762 ◽  
Author(s):  
Hsiang-Chun Hsu ◽  
Hideo Ema ◽  
Mitsujiro Osawa ◽  
Yukio Nakamura ◽  
Toshio Suda ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Receptor Tyrosine Kinase ◽  
Fetal Liver ◽  
Newborn Mice ◽  
Hematopoietic Stem ◽  
Fetal Liver Cells

Tie-2 receptor tyrosine kinase expressed in endothelial and hematopoietic cells is believed to play a role in both angiogenesis and hematopoiesis during development of the mouse embryo. This article addressed whether Tie-2 is expressed on fetal liver hematopoietic stem cells (HSCs) at day 14 of gestation. With the use of anti–Tie-2 monoclonal antibody, its expression was detected in approximately 7% of an HSC population of Kit-positive, Sca-1–positive, lineage-negative or -low, and AA4.1-positive (KSLA) cells. These Tie-2–positive KSLA (T+ KSLA) cells represent 0.01% to 0.02% of fetal liver cells. In vitro colony and in vivo competitive repopulation assays were performed for T+ KSLA cells and Tie-2–negative KSLA (T− KSLA) cells. In the presence of stem cell factor, interleukin-3, and erythropoietin, 80% of T+ KSLA cells formed colonies in vitro, compared with 40% of T− KSLA cells. Long-term multilineage repopulating cells were detected in T+ KSLA cells, but not in T− KSLA cells. An in vivo limiting dilution analysis revealed that at least 1 of 8 T+ KSLA cells were such repopulating cells. The successful secondary transplantation initiated with a limited number of T+ KSLA cells suggests that these cells have self-renewal potential. In addition, engraftment of T+ KSLA cells in conditioned newborn mice indicates that these HSCs can be adapted equally by the adult and newborn hematopoietic environments. The data suggest that T+ KSLA cells represent HSCs in the murine fetal liver.

Hematopoietic stem cells express Tie-2 receptor in the murine fetal liver

Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3757-3762 ◽  
Author(s):  
Hsiang-Chun Hsu ◽  
Hideo Ema ◽  
Mitsujiro Osawa ◽  
Yukio Nakamura ◽  
Toshio Suda ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Receptor Tyrosine Kinase ◽  
Fetal Liver ◽  
Newborn Mice ◽  
Hematopoietic Stem ◽  
Fetal Liver Cells

Abstract Tie-2 receptor tyrosine kinase expressed in endothelial and hematopoietic cells is believed to play a role in both angiogenesis and hematopoiesis during development of the mouse embryo. This article addressed whether Tie-2 is expressed on fetal liver hematopoietic stem cells (HSCs) at day 14 of gestation. With the use of anti–Tie-2 monoclonal antibody, its expression was detected in approximately 7% of an HSC population of Kit-positive, Sca-1–positive, lineage-negative or -low, and AA4.1-positive (KSLA) cells. These Tie-2–positive KSLA (T+ KSLA) cells represent 0.01% to 0.02% of fetal liver cells. In vitro colony and in vivo competitive repopulation assays were performed for T+ KSLA cells and Tie-2–negative KSLA (T− KSLA) cells. In the presence of stem cell factor, interleukin-3, and erythropoietin, 80% of T+ KSLA cells formed colonies in vitro, compared with 40% of T− KSLA cells. Long-term multilineage repopulating cells were detected in T+ KSLA cells, but not in T− KSLA cells. An in vivo limiting dilution analysis revealed that at least 1 of 8 T+ KSLA cells were such repopulating cells. The successful secondary transplantation initiated with a limited number of T+ KSLA cells suggests that these cells have self-renewal potential. In addition, engraftment of T+ KSLA cells in conditioned newborn mice indicates that these HSCs can be adapted equally by the adult and newborn hematopoietic environments. The data suggest that T+ KSLA cells represent HSCs in the murine fetal liver.

Human reconstituting hematopoietic stem cells up-regulate Fas expression upon active cell cycling but remain resistant to Fas-induced suppression

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Ingunn Dybedal ◽  
Liping Yang ◽  
David Bryder ◽  
Ingbritt Aastrand-Grundstrom ◽  
Karin Leandersson ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Severe Combined Immunodeficiency ◽  
Constitutive Expression ◽  
Human Cord Blood ◽  
Hematopoietic Stem ◽  
Nonobese Diabetic

Abstract The Fas receptor and its ligand have been implicated in mediating the bone marrow (BM) suppression observed in graft-versus-host disease and a number of other BM-failure syndromes. However, previous studies have suggested that Fas is probably not expressed on human hematopoietic stem cells (HSCs), but up-regulated as a consequence of their commitment and differentiation, suggesting that progenitors or differentiated blood cells, rather than HSCs, are the targets of Fas-mediated suppression. The present studies confirm that candidate HSCs in human cord blood and BM lack constitutive expression of Fas, but demonstrate that Fas expression on CD34+ progenitor and stem cells is correlated to their cell cycle and activation status. With the use of recently developed in vitro conditions promoting HSC self-renewing divisions, Fas was up-regulated on virtually all HSCs capable of multilineage reconstituting nonobese diabetic/severe combined immunodeficiency (NOD-SCID) mice in vivo, as well as on long-term culture-initiating cells (LTC-ICs). Similarly, in vivo cycling of NOD-SCID repopulating cells upon transplantation, resulted in up-regulation of Fas expression. However, repopulating HSCs expressing high levels of Fas remained highly resistant to Fas-mediated suppression, and HSC function was compromised only upon coactivation with tumor necrosis factor. Thus, reconstituting human HSCs up-regulate Fas expression upon active cycling, demonstrating that HSCs could be targets for Fas-mediated BM suppression. (Blood. 2003;102: 118-126)

scholarly journals Phenotypic and functional characterization of competitive long-term repopulating hematopoietic stem cells enriched from 5-fluorouracil- treated murine marrow

Blood ◽  
1993 ◽  
Vol 81 (9) ◽  
pp. 2310-2320 ◽  
Author(s):  
SJ Szilvassy ◽  
S Cory
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Functional Characterization ◽  
Significant Proportion ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Clonogenic Cell

Lymphomyeloid stem cells from the bone marrow of C57BL/6 mice treated with 5-fluorouracil (5-FU) were characterized with respect to 12 parameters using fluorescence-activated cell sorting and a competitive long-term repopulation assay. Stem cells were larger than lymphocytes and exhibited side light-scatter characteristic of blast cells. Most expressed low levels of Thy-1.2, high levels of Sca-1 (Ly6-A/E), H-2Kb, and AA4.1 antigens and stained brightly with rhodamine-123. Significantly, most long-term repopulating cells also expressed CD4, some at high density. In addition, a significant proportion displayed low to medium levels of the “lineage-specific” markers CD45R (B220), Gr- 1, and TER-119. A simple and rapid multiparameter sorting procedure enriched the stem cells 100-fold and substantially removed most other clonogenic cell types, including day 12 spleen colony-forming cells. Cells able to generate cobblestone colonies on stromal cells in vitro were co-enriched. Lethally irradiated mice transplanted with limiting numbers of the sorted stem cells did not survive unless cotransplanted with “compromised” marrow cells prepared by prior serial transplantation and shown to be depleted of long-term repopulating activity. A significant number of recipients transplanted with 25 to 100 sorted cells contained donor-derived B and T lymphocytes and granulocytes in their peripheral blood for at least 6 months. Limiting dilution analysis in vivo indicated that the frequency of competitive long-term repopulating units (CRU) in the sorted population was at least 1 in 60 cells. The calculated frequency of CRU was largely independent of the time of recipient analysis between 10 and 52 weeks, indicating that highly enriched stem cells can be recruited relatively early in certain transplant settings. This simple enrichment and assay strategy for repopulating hematopoietic stem cells should facilitate further analysis of their regulation in vivo.

Steel factor responsiveness regulates the high self-renewal phenotype of fetal hematopoietic stem cells

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 5043-5048 ◽  
Author(s):  
Michelle B. Bowie ◽  
David G. Kent ◽  
Michael R. Copley ◽  
Connie J. Eaves
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Wild Type ◽  
Developmentally Regulated ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Steel Factor ◽  
Reduced Rate

Abstract Fetal hematopoietic stem cells (HSCs) regenerate daughter HSCs in irradiated recipients more rapidly than do adult HSCs. However, both types of HSCs divide in vitro with the same cell-cycle transit times, suggesting different intrinsically determined self-renewal activities. To investigate the mechanism(s) underlying these differences, we compared fetal and adult HSC responses to Steel factor (SF) stimulation in vitro and in vivo. These experiments were undertaken with both wild-type cells and W41/W41 cells, which have a functionally deficient c-kit kinase. In vitro, fetal HSC self-renewal divisions, like those of adult HSCs, were found to be strongly dependent on c-kit activation, but the fetal HSCs responded to much lower SF concentrations in spite of indistinguishable levels of c-kit expression. Fetal W41/W41 HSCs also mimicked adult wild-type HSCs in showing the same reduced rate of amplification in irradiated adult hosts (relative to fetal wild-type HSCs). Assessment of various proliferation and signaling gene transcripts in fetal and adult HSCs self-renewing in vitro revealed a singular difference in Ink4c expression. We conclude that the ability of fetal HSCs to execute symmetric self-renewal divisions more efficiently than adult HSCs in vivo may be dependent on specific developmentally regulated signals that act downstream of the c-kit kinase.

scholarly journals The Role of Apoptosis in the Regulation of Hematopoietic Stem Cells

2000 ◽  
Vol 191 (2) ◽  
pp. 253-264 ◽  
Author(s):  
Jos Domen ◽  
Samuel H. Cheshier ◽  
Irving L. Weissman
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Hematopoietic Cells ◽  
Wild Type ◽  
Direct Role ◽  
Hematopoietic Stem

Hematopoietic stem cells (HSC) give rise to cells of all hematopoietic lineages, many of which are short lived. HSC face developmental choices: self-renewal (remain an HSC with long-term multilineage repopulating potential) or differentiation (become an HSC with short-term multilineage repopulating potential and, eventually, a mature cell). There is a large overcapacity of differentiating hematopoietic cells and apoptosis plays a role in regulating their numbers. It is not clear whether apoptosis plays a direct role in regulating HSC numbers. To address this, we have employed a transgenic mouse model that overexpresses BCL-2 in all hematopoietic cells, including HSC: H2K-BCL-2. Cells from H2K-BCL-2 mice have been shown to be protected against a wide variety of apoptosis-inducing challenges. This block in apoptosis affects their HSC compartment. H2K-BCL-2–transgenic mice have increased numbers of HSC in bone marrow (2.4× wild type), but fewer of these cells are in the S/G2/M phases of the cell cycle (0.6× wild type). Their HSC have an increased plating efficiency in vitro, engraft at least as well as wild-type HSC in vivo, and have an advantage following competitive reconstitution with wild-type HSC.

scholarly journals Phenotypic and functional characterization of competitive long-term repopulating hematopoietic stem cells enriched from 5-fluorouracil- treated murine marrow

Blood ◽  
1993 ◽  
Vol 81 (9) ◽  
pp. 2310-2320 ◽  
Author(s):  
SJ Szilvassy ◽  
S Cory
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Functional Characterization ◽  
Significant Proportion ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Clonogenic Cell

Abstract Lymphomyeloid stem cells from the bone marrow of C57BL/6 mice treated with 5-fluorouracil (5-FU) were characterized with respect to 12 parameters using fluorescence-activated cell sorting and a competitive long-term repopulation assay. Stem cells were larger than lymphocytes and exhibited side light-scatter characteristic of blast cells. Most expressed low levels of Thy-1.2, high levels of Sca-1 (Ly6-A/E), H-2Kb, and AA4.1 antigens and stained brightly with rhodamine-123. Significantly, most long-term repopulating cells also expressed CD4, some at high density. In addition, a significant proportion displayed low to medium levels of the “lineage-specific” markers CD45R (B220), Gr- 1, and TER-119. A simple and rapid multiparameter sorting procedure enriched the stem cells 100-fold and substantially removed most other clonogenic cell types, including day 12 spleen colony-forming cells. Cells able to generate cobblestone colonies on stromal cells in vitro were co-enriched. Lethally irradiated mice transplanted with limiting numbers of the sorted stem cells did not survive unless cotransplanted with “compromised” marrow cells prepared by prior serial transplantation and shown to be depleted of long-term repopulating activity. A significant number of recipients transplanted with 25 to 100 sorted cells contained donor-derived B and T lymphocytes and granulocytes in their peripheral blood for at least 6 months. Limiting dilution analysis in vivo indicated that the frequency of competitive long-term repopulating units (CRU) in the sorted population was at least 1 in 60 cells. The calculated frequency of CRU was largely independent of the time of recipient analysis between 10 and 52 weeks, indicating that highly enriched stem cells can be recruited relatively early in certain transplant settings. This simple enrichment and assay strategy for repopulating hematopoietic stem cells should facilitate further analysis of their regulation in vivo.

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