Cell Cycle Regulation and Cell Fate Decisions in Hematopoietic Stem Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1349-1349
Author(s):  
Emmanuelle Passegue ◽  
Amy J. Wagers ◽  
Sylvie Giuriato ◽  
Wade C. Anderson ◽  
Irving L. Weissman
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Fate ◽  
Cell Cycle Regulation ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions ◽  
Cycle Regulation

Abstract The blood is a perpetually renewing tissue seeded by a rare population of adult bone marrow hematopoietic stem cells (HSC). During steady-state hematopoiesis, the HSC population is relatively quiescent but constantly maintains a low numbers of cycling cells that differentiate to produce the various lineage of mature blood cells. However, in response to hematological stress, the entire HSC population can be recruited into cycle to self-renew and regenerate the blood-forming system. HSC proliferation is therefore highly adaptative and requires appropriate regulation of cell cycle progression to drive both differentiation-associated and self-renewal-associated proliferation, without depletion of the stem cell pool. Although the molecular events controlling HSC proliferation are still poorly understood, they are likely determined, at least in part, by regulated expression and/or function of components and regulators of the cell cycle machinery. Here, we demonstrate that the long-term self-renewing HSC (defined as Lin−/c-Kit+/Sca-1+/Thy1.1int/Flk2−) exists in two distinct states that are both equally important for their in vivo functions as stem cells: a numerically dominant quiescent state, which is critical for HSC function in hematopoietic reconstitution; and a proliferative state, which represents almost a fourth of this population and is essential for HSC functions in differentiation and self-renewal. We show that when HSC exit quiescence and enter G1 as a prelude to cell division, at least two critical events occur: first, during the G1 and subsequent S-G2/M phases, they temporarily lose efficient in vivo engraftment activity, while retaining in vitro differentiation potential; and second, they select the particular cell cycle proteins that are associated with specific developmental outcomes (self-renewal vs. differentiation) and developmental fates (myeloid vs. lymphoid). Together, these findings provide a direct link between HSC proliferation, cell cycle regulation and cell fate decisions that have critical implications for both the therapeutic use of HSC and the understanding of leukemic transformation.

scholarly journals Cell cycle regulation in hematopoietic stem cells

2011 ◽  
Vol 195 (5) ◽  
pp. 709-720 ◽  
Author(s):  
Eric M. Pietras ◽  
Matthew R. Warr ◽  
Emmanuelle Passegué
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Cycle Regulation ◽  
Critical Role ◽  
Cellular Damage ◽  
Fetal Life ◽  
Extrinsic Factors ◽  
Hematopoietic Stem ◽  
Cycle Regulation

Hematopoietic stem cells (HSCs) give rise to all lineages of blood cells. Because HSCs must persist for a lifetime, the balance between their proliferation and quiescence is carefully regulated to ensure blood homeostasis while limiting cellular damage. Cell cycle regulation therefore plays a critical role in controlling HSC function during both fetal life and in the adult. The cell cycle activity of HSCs is carefully modulated by a complex interplay between cell-intrinsic mechanisms and cell-extrinsic factors produced by the microenvironment. This fine-tuned regulatory network may become altered with age, leading to aberrant HSC cell cycle regulation, degraded HSC function, and hematological malignancy.

Cell Cycle Regulation in Human Hematopoietic Stem Cells: From Isolation to Activation

2002 ◽  
Vol 43 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Maria Marone ◽  
Daniela de Ritis ◽  
Giuseppina Bonanno ◽  
Simona Mozzetti ◽  
Sergio Rutella ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Cycle Regulation ◽  
Hematopoietic Stem ◽  
Cycle Regulation

Foxo3a Is Essential for the Quiescence and Self-Renewal of Hematopoietic Stem Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 442-442
Author(s):  
Kana Miyamoto ◽  
Atsushi Hirao ◽  
Kiyomi Y. Araki ◽  
Fumio Arai ◽  
Kazuhito Naka ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Blood Cells ◽  
Quiescent State ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Functions

Abstract Hematopoietic stem cells (HSCs) are maintained in an undifferentiated quiescent state in bone marrow (BM). Quiescent stem cells show resistance to various stresses, suggesting that mechanisms for protection of HSC life from stress contribute to maintenance of self-renewal capacity through a whole life in animals. We hypothesized that a signaling pathway for regulating aging might be involved in stem cell functions. FOXO transcription factors belong to the forkhead family of transcriptional regulators characterized by a conserved DNA-binding domain termed “forkhead box”. In C.elegans, genetic analyses have revealed the existence of a conserved insulin-like signaling involved in longevity. Conservation of this pathways lead to speculation that forkhead transcriptional factor are involved in life span in mammals. It was known that active-state Foxo3a is localized in nucleus, and we found HSC-specific nuclear localization of Foxo3a by immunocytochemistric study, therefore we generated gene-targeted Foxo3a−/− mice to analyze roles of Foxo in HSC regulation. Peripheral blood count showed decreased number of red blood cells in Foxo3a−/− mice, but numbers of white blood cells and platelets were normal. In colony-forming assay, we detected the numbers and sizes of myeloid, erythroid and mixed colonies derived from Foxo3a−/− BM mononuclear cells were all normal. These results suggest that the proliferation and differentiation of Foxo3a−/− progenitors were normal. However, the number of colony-forming cells present in long-term culture of Foxo3a−/− c-kit+Sca-1+Lin− (KSL) cells with stroma was significantly reduced. The ability of Foxo3a−/− HSCs to support long-term reconstitution of hematopoiesis in a competitive transplantation assay was also impaired, indicating that self-renewal capacity of HSCs was defective in Foxo3a−/− mice. To understand the mechanisms of this phenotypes, we evaluated the cell cycle status using BrdU (5-bromodeoxyuridine) incorporation but found no difference in Foxo3a+/+ and Foxo3a−/− progenitor cells. To directly evaluate HSC quiescence in Foxo3a−/− mice, we stained CD34−KSL cells with Pyronin Y. Although most Foxo3a+/+ CD34−KSL cells stained negatively for Pyronin Y, a sizable Pyronin Y+ population was detected among Foxo3a−/− CD34−KSL cells, demonstrating that loss of Foxo3a leads to a defect in the maintenance of HSCs quiescence. Since p38MAPK is selectively activated by environmental stress, we evaluated the activation status of p38MAPK in Foxo3a+/+ and Foxo3a−/− HSCs. Frequency of phosphorylated p38MAPK+ cells in Foxo3a−/−CD34−KSL cells was significantly increased than that of Foxo3a+/+CD34−KSL cells. Our results suggest that Foxo3a−/− HSCs subjected to tangible stress in vivo. Finally, we investigated the sensitivity of Foxo3a−/− mice to weekly 5-fluorouracil treatment in vivo. Although 60% of Foxo3a+/+mice survived for at least 4 weeks post-injection, all Foxo3a−/− mice were dead in 4 weeks. It suggests that Foxo3a protects hematopoietic cells from destruction by cell cycle-dependent myelotoxic agent. Taken together, our results demonstrate that Foxo3a plays a pivotal role in maintaining HSC quiescence and stress resistance.

scholarly journals Cell cycle regulation in hematopoietic stem cells

2011 ◽  
Vol 208 (13) ◽  
pp. i34-i34 ◽  
Author(s):  
Eric M. Pietras ◽  
Matthew R. Warr ◽  
Emmanuelle Passegué
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Cycle Regulation ◽  
Hematopoietic Stem ◽  
Cycle Regulation

scholarly journals Maintenance of Hematopoietic Stem Cells Through Regulation of Wnt and mTOR Pathways.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2309-2309
Author(s):  
Jian Huang ◽  
Peter S. Klein
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Signaling Pathways ◽  
Glycogen Synthase ◽  
Dependent Manner ◽  
Mtor Inhibition ◽  
Self Renewal ◽  
Hematopoietic Stem

Abstract Abstract 2309 Hematopoietic stem cells (HSCs) maintain the ability to self-renew and to differentiate into all lineages of the blood. The signaling pathways regulating hematopoietic stem cell (HSCs) self-renewal and differentiation are not well understood. We are very interested in understanding the roles of glycogen synthase kinase-3 (Gsk3) and the signaling pathways regulated by Gsk3 in HSCs. In our previous study (Journal of Clinical Investigation, December 2009) using loss of function approaches (inhibitors, RNAi, and knockout) in mice, we found that Gsk3 plays a pivotal role in controlling the decision between self-renewal and differentiation of HSCs. Disruption of Gsk3 in bone marrow transiently expands HSCs in a b-catenin dependent manner, consistent with a role for Wnt signaling. However, in long-term repopulation assays, disruption of Gsk3 progressively depletes HSCs through activation of mTOR. This long-term HSC depletion is prevented by mTOR inhibition and exacerbated by b-catenin knockout. Thus GSK3 regulates both Wnt and mTOR signaling in HSCs, with opposing effects on HSC self-renewal such that inhibition of Gsk3 in the presence of rapamycin expands the HSC pool in vivo. In the current study, we found that suppression of the mammalian target of rapamycin (mTOR) pathway, an established nutrient sensor, combined with activation of canonical Wnt/ß-catenin signaling, allows the ex vivo maintenance of human and mouse long-term HSCs under cytokine-free conditions. We also show that combining two clinically approved medications that activate Wnt/ß-catenin signaling and inhibit mTOR increases the number of long-term HSCs in vivo. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Clonal-level lineage commitment pathways of hematopoietic stem cells in vivo

2019 ◽  
Vol 116 (4) ◽  
pp. 1447-1456 ◽  
Author(s):  
Rong Lu ◽  
Agnieszka Czechowicz ◽  
Jun Seita ◽  
Du Jiang ◽  
Irving L. Weissman
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Hematopoietic Stem Cell ◽  
Lineage Commitment ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Hematopoietic System ◽  
Different Levels

While the aggregate differentiation of the hematopoietic stem cell (HSC) population has been extensively studied, little is known about the lineage commitment process of individual HSC clones. Here, we provide lineage commitment maps of HSC clones under homeostasis and after perturbations of the endogenous hematopoietic system. Under homeostasis, all donor-derived HSC clones regenerate blood homogeneously throughout all measured stages and lineages of hematopoiesis. In contrast, after the hematopoietic system has been perturbed by irradiation or by an antagonistic anti-ckit antibody, only a small fraction of donor-derived HSC clones differentiate. Some of these clones dominantly expand and exhibit lineage bias. We identified the cellular origins of clonal dominance and lineage bias and uncovered the lineage commitment pathways that lead HSC clones to different levels of self-renewal and blood production under various transplantation conditions. This study reveals surprising alterations in HSC fate decisions directed by conditioning and identifies the key hematopoiesis stages that may be manipulated to control blood production and balance.

CCND1–CDK4–mediated cell cycle progression provides a competitive advantage for human hematopoietic stem cells in vivo

2015 ◽  
Vol 210 (2) ◽  
pp. 2102OIA144
Author(s):  
Nicole Mende ◽  
Erika E Kuchen ◽  
Mathias Lesche ◽  
Tatyana Grinenko ◽  
Konstantinos D Kokkaliaris ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Competitive Advantage ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Hematopoietic Stem

Hoxb4-deficient mice undergo normal hematopoietic development but exhibit a mild proliferation defect in hematopoietic stem cells

Blood ◽  
2004 ◽  
Vol 103 (11) ◽  
pp. 4126-4133 ◽  
Author(s):  
Ann C. M. Brun ◽  
Jon Mar Björnsson ◽  
Mattias Magnusson ◽  
Nina Larsson ◽  
Per Leveén ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Hox Genes ◽  
Fetal Liver ◽  
Severe Combined Immunodeficiency ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Mild Reduction

Abstract Enforced expression of Hoxb4 dramatically increases the regeneration of murine hematopoietic stem cells (HSCs) after transplantation and enhances the repopulation ability of human severe combined immunodeficiency (SCID) repopulating cells. Therefore, we asked what physiologic role Hoxb4 has in hematopoiesis. A novel mouse model lacking the entire Hoxb4 gene exhibits significantly reduced cellularity in spleen and bone marrow (BM) and a subtle reduction in red blood cell counts and hemoglobin values. A mild reduction was observed in the numbers of primitive progenitors and stem cells in adult BM and fetal liver, whereas lineage distribution was normal. Although the cell cycle kinetics of primitive progenitors was normal during endogenous hematopoiesis, defects in proliferative responses of BM Lin- Sca1+ c-kit+ stem and progenitor cells were observed in culture and in vivo after the transplantation of BM and fetal liver HSCs. Quantitative analysis of mRNA from fetal liver revealed that a deficiency of Hoxb4 alone changed the expression levels of several other Hox genes and of genes involved in cell cycle regulation. In summary, the deficiency of Hoxb4 leads to hypocellularity in hematopoietic organs and impaired proliferative capacity. However, Hoxb4 is not required for the generation of HSCs or the maintenance of steady state hematopoiesis.

Malignant Myeloma Cells Impair Phenotype and Function of stem and Progenitor Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1799-1799
Author(s):  
Ingmar Bruns ◽  
Sebastian Büst ◽  
Akos G. Czibere ◽  
Ron-Patrick Cadeddu ◽  
Ines Brückmann ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Progenitor Cells ◽  
Plasma Cells ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Healthy Donors ◽  
Stem And Progenitor Cells

Abstract Abstract 1799 Poster Board I-825 Multiple myeloma (MM) patients often present with anemia at the time of initial diagnosis. This has so far only attributed to a physically marrow suppression by the invading malignant plasma cells and the overexpression of Fas-L and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) by malignant plasma cells triggering the death of immature erythroblasts. Still the impact of MM on hematopoietic stem cells and their niches is scarcely established. In this study we analyzed highly purified CD34+ hematopoietic stem and progenitor cell subsets from the bone marrow of newly diagnosed MM patients in comparison to normal donors. Quantitative flowcytometric analyses revealed a significant reduction of the megakaryocyte-erythrocyte progenitor (MEP) proportion in MM patients, whereas the percentage of granulocyte-macrophage progenitors (GMP) was significantly increased. Proportions of hematopoietic stem cells (HSC) and myeloid progenitors (CMP) were not significantly altered. We then asked if this is also reflected by clonogenic assays and found a significantly decreased percentage of erythroid precursors (BFU-E and CFU-E). Using Affymetrix HU133 2.0 gene arrays, we compared the gene expression signatures of stem cells and progenitor subsets in MM patients and healthy donors. The most striking findings so far reflect reduced adhesive and migratory potential, impaired self-renewal capacity and disturbed B-cell development in HSC whereas the MEP expression profile reflects decreased in cell cycle activity and enhanced apoptosis. In line we found a decreased expression of the adhesion molecule CD44 and a reduced actin polymerization in MM HSC by immunofluorescence analysis. Accordingly, in vitro adhesion and transwell migration assays showed reduced adhesive and migratory capacities. The impaired self-renewal capacity of MM HSC was functionally corroborated by a significantly decreased long-term culture initiating cell (LTC-IC) frequency in long term culture assays. Cell cycle analyses revealed a significantly larger proportion of MM MEP in G0-phase of the cell cycle. Furthermore, the proportion of apoptotic cells in MM MEP determined by the content of cleaved caspase 3 was increased as compared to MEP from healthy donors. Taken together, our findings indicate an impact of MM on the molecular phenotype and functional properties of stem and progenitor cells. Anemia in MM seems at least partially to originate already at the stem and progenitor level. Disclosures Off Label Use: AML with multikinase inhibitor sorafenib, which is approved by EMEA + FDA for renal cell carcinoma.

Cripto Selectively Expands a Distinct Population of Hematopoietic Stem Cells Expressing the Cell Surface Receptor GRP78 and Strongly Induces An Immature Phenotype In Vivo After Ex Vivo Culture

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 405-405
Author(s):  
Kenichi Miharada ◽  
Göran Karlsson ◽  
Jonas Larsson ◽  
Emma Larsson ◽  
Kavitha Siva ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Peripheral Blood ◽  
Distinct Population ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Total Bone Marrow

Abstract Abstract 405 Cripto is a member of the EGF-CFC soluble protein family and has been identified as an important factor for the proliferation/self-renewal of ES and several types of tumor cells. The role for Cripto in the regulation of hematopoietic cells has been unknown. Here we show that Cripto is a potential new candidate factor to increase self-renewal and expand hematopoietic stem cells (HSCs) in vitro. The expression level of Cripto was analyzed by qRT-PCR in several purified murine hematopoietic cell populations. The findings demonstrated that purified CD34-KSL cells, known as highly concentrated HSC population, had higher expression levels than other hematopoietic progenitor populations including CD34+KSL cells. We asked how Cripto regulates HSCs by using recombinant mouse Cripto (rmCripto) for in vitro and in vivo experiments. First we tested the effects of rmCripto on purified hematopoietic stem cells (CD34-LSK) in vitro. After two weeks culture in serum free media supplemented with 100ng/ml of SCF, TPO and 500ng/ml of rmCripto, 30 of CD34-KSL cells formed over 1,300 of colonies, including over 60 of GEMM colonies, while control cultures without rmCripto generated few colonies and no GEMM colonies (p<0.001). Next, 20 of CD34-KSL cells were cultured with or without rmCripto for 2 weeks and transplanted to lethally irradiated mice in a competitive setting. Cripto treated donor cells showed a low level of reconstitution (4–12%) in the peripheral blood, while cells cultured without rmCripto failed to reconstitute. To define the target population and the mechanism of Cripto action, we analyzed two cell surface proteins, GRP78 and Glypican-1, as potential receptor candidates for Cripto regulation of HSC. Surprisingly, CD34-KSL cells were divided into two distinct populations where HSC expressing GRP78 exhibited robust expansion of CFU-GEMM progenitor mediated by rmCripto in CFU-assay whereas GRP78- HSC did not respond (1/3 of CD34-KSL cells were GRP78+). Furthermore, a neutralization antibody for GRP78 completely inhibited the effect of Cripto in both CFU-assay and transplantation assay. In contrast, all lineage negative cells were Glypican-1 positive. These results suggest that GRP78 must be the functional receptor for Cripto on HSC. We therefore sorted these two GRP78+CD34-KSL (GRP78+HSC) and GRP78-CD34-KSL (GRP78-HSC) populations and transplanted to lethally irradiated mice using freshly isolated cells and cells cultured with or without rmCripto for 2 weeks. Interestingly, fresh GRP78-HSCs showed higher reconstitution than GRP78+HSCs (58–82% and 8–40%, p=0.0038) and the reconstitution level in peripheral blood increased rapidly. In contrast, GRP78+HSC reconstituted the peripheral blood slowly, still at a lower level than GRP78-HSC 4 months after transplantation. However, rmCripto selectively expanded (or maintained) GRP78+HSCs but not GRP78-HSCs after culture and generated a similar level of reconstitution as freshly transplanted cells (12–35%). Finally, bone marrow cells of engrafted recipient mice were analyzed at 5 months after transplantation. Surprisingly, GRP78+HSC cultured with rmCripto showed higher reconstitution of the CD34-KSL population in the recipients' bone marrow (45–54%, p=0.0026), while the reconstitution in peripheral blood and in total bone marrow was almost the same. Additionally, most reconstituted CD34-KSL population was GRP78+. Interestingly freshly transplanted sorted GRP78+HSC and GRP78-HSC can produce the GRP78− and GRP78+ populations in the bone marrow and the ratio of GRP78+/− cells that were regenerated have the same proportion as the original donor mice. Compared to cultured cells, the level of reconstitution (peripheral blood, total bone marrow, HSC) in the recipient mice was almost similar. These results indicate that the GRP78 expression on HSC is reversible, but it seems to be “fixed” into an immature stage and differentiate with lower efficiency toward mature cells after long/strong exposure to Cripto signaling. Based on these findings, we propose that Cripto is a novel factor that maintains HSC in an immature state and may be a potent candidate for expansion of a distinct population of GRP78 expressing HSC. Disclosures: No relevant conflicts of interest to declare.

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