scholarly journals Foxo3a Is Essential for Maintenance of the Hematopoietic Stem Cell Pool

2007 ◽  
Vol 1 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Kana Miyamoto ◽  
Kiyomi Y. Araki ◽  
Kazuhito Naka ◽  
Fumio Arai ◽  
Keiyo Takubo ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hematopoietic Stem ◽  
Cell Pool ◽  
Stem Cell Pool

The F-Box Protein NIPA Regulates the Hematopoietic Stem Cell Pool

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2330-2330
Author(s):  
Stefanie Kreutmair ◽  
Anna Lena Illert ◽  
Rouzanna Istvanffy ◽  
Melanie Sickinger ◽  
Christina Eckl ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Bone Marrow Cells ◽  
Wild Type ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Pool ◽  
F Box Protein ◽  
Stem Cell Pool

Abstract Abstract 2330 Hematopoietic stem cells (HSCs) are characterized by their ability to self-renewal and multilineage differentiation. Since mostly HSCs exist in a quiescent state re-entry into cell cycle is essential for their regeneration and differentiation and the expression of numerous cell cycle regulators must be tightly controlled. We previously characterized NIPA (Nuclear Interaction Partner of ALK) as a F-Box protein that defines an oscillating ubiquitin E3 ligase targeting nuclear cyclin B1 in interphase thus contributing to the timing of mitotic entry. To examine the function of NIPA on vivo, we generated NIPA deficient animals, which are viable but sterile due to a defect in recombination and testis stem cell maintenance. To further characterize the role of NIPA in stem cell maintenance and self-renewal we investigated hematopoiesis in NIPA deficient animals. Peripheral blood counts taken at different ages revealed no apparent difference between NIPA knockout and wild type mice in numbers and differentiation. In contrast, looking at the hematopoietic stem cell pool, FACS analyses of bone marrow showed significantly decreased numbers of Lin-Sca1+cKit+ (LSK) cells in NIPA deficient animals, where LSKs were reduced to 40% of wild type littermates (p=0,0171). This effect was only apparent in older animals, where physiologically higher LSK numbers have to compensate for the exhaustion of the stem cell pool. Additionally, older NIPA deficient mice have only half the amount of multi myeloid progenitors (MMPs) in contrast to wild type animals. To examine efficient activation of stem cells to self-renew in response to myeloid depression, we treated young and old mice with the cytotoxic drug (5-FU) four days before bone marrow harvest. As expected, 5-FU activated hematopoietic progenitors in wild type animals, whereas NIPA deficient progenitors failed to compensate to 5-FU depression, e.g. LSKs of NIPA knockout mice were reduced to 50% of wild type levels (p<0.001), CD150+CD34+ Nipa deficient cells to 20% of wild type levels (p<0.0001). Interestingly, these effects were seen in all NIPA deficient animals independent of age, allowing us to trigger the self-renewal phenotype by activating the hematopoietic stem cell pool. Using competitive bone marrow transplantation assays, CD45.2 positive NIPA deficient or NIPA wild type bone marrow cells were mixed with CD45.1 positive wild type bone marrow cells and transplanted into lethally irradiated CD45.2 positive recipient mice. Thirty days after transplantation, FACS analysis of peripheral blood and bone marrow showed reduced numbers of NIPA knockout cells in comparison to NIPA wild type bone marrow recipient mice. This result was even more severe with aging of transplanted mice, where NIPA deficient cells were reduced to less than 10% of the level of wild type cells in bone marrow of sacrificed mice 6 months after transplantation, pointing to a profound defect in repopulation capacity of NIPA deficient HSCs. Taken together our results demonstrate a unique and critical role of NIPA in regulating the primitive hematopoietic compartment as a regulator of self-renewal, cycle capacity and HSC expansion. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Macrophage-Lineage Cells Negatively Regulate the Hematopoietic Stem Cell Pool in Response to Interferon Gamma at Steady State and During Infection

Stem Cells ◽  
2015 ◽  
Vol 33 (7) ◽  
pp. 2294-2305 ◽  
Author(s):  
Amanda McCabe ◽  
Yubin Zhang ◽  
Vinh Thai ◽  
Maura Jones ◽  
Michael B. Jordan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Steady State ◽  
Hematopoietic Stem Cell ◽  
Interferon Gamma ◽  
Hematopoietic Stem ◽  
Cell Pool ◽  
Macrophage Lineage ◽  
Stem Cell Pool

scholarly journals Effect of Cyclophosphamide on the Murine Hematopoietic Stem Cell Compartment as Measured by Different Assay Techniques

Blood ◽  
1971 ◽  
Vol 38 (6) ◽  
pp. 706-714 ◽  
Author(s):  
SAMUEL HELLMAN ◽  
HELEN E. GRATE
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Erythroid Differentiation ◽  
Cell Compartment ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Cell Pool ◽  
Murine Hematopoietic Stem Cell ◽  
White Blood Cell Counts ◽  
Stem Cell Pool

Abstract Three different methods have been used to measure the survival of the hematopoietic stem cell pool following treatment with cyclophosphamide. Two of these systems measure the stem cell pool by its ability to proliferate and differentiate into mature progeny. In both these methods irradiated recipient mice receive syngeneic bone marrow from either normal or cyclophosphamide-treated animals. A period of time is allowed for the transplanted progenitor cells to divide and differentiate, and then the progeny produced are assayed. Ability to form red blood cells is assessed by the amount of radioactive iron incorporated into newly formed erythrocytes. Capacity for granulocyte formation is measured by peripheral white blood cell counts following endotoxin stimulation. The pool as measured by its ability to produce erythrocytic progeny appears to be more sensitive than as measured by its ability to produce granulocytic progeny. The spleen colony assay gives results similar to the assay of granulocytic progeny. These results, taken with previous data indicating decrease in erythroid precursors in spleen colonies derived from cells surviving cyclophosphamide, are interpreted as indicating a decrease in ability for erythroid differentiation in cells surviving cyclophosphamide.

Sfrp2 from the niche is required to maintain the regeneration of the hematopoietic stem cell pool

2017 ◽  
Vol 53 ◽  
pp. S96
Author(s):  
Rouzanna Istvanffy ◽  
Franziska Ruf ◽  
Christina Schreck ◽  
Sandra Romero ◽  
Franziska Hettler ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hematopoietic Stem ◽  
Cell Pool ◽  
Stem Cell Pool
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