scholarly journals Spleen stromal cell lines selectively support erythroid colony formation

Blood ◽  
1989 ◽  
Vol 74 (7) ◽  
pp. 2391-2397 ◽  
Author(s):  
N Yanai ◽  
Y Matsuya ◽  
M Obinata

Mouse stromal cell lines (MSS lines) have been established from the spleens of newborn mice in culture at a low serum concentration. These MSS lines support the proliferation and differentiation of the erythroid progenitor cells from mouse fetal livers and bone marrow in a semisolid medium in the presence of erythropoietin. Larger colonies of over 1,000 benzidine-positive erythroid cells were developed from the fetal liver cells on the MSS cell layers after 6 days of incubation. These layers also support the maturation of the erythroid cells since the enucleation process of the latter was observed in large erythroid colonies. Metabolically active MSS cells are apparently required to support the proliferation and differentiation of the erythroid progenitor cells, because neither the MSS cells inactivated with fixation nor the conditioned media of MSS cells promoted the erythroid colony formation. These studies demonstrate that MSS lines specifically support the proliferation and differentiation of the erythroid progenitor cells in vitro and that stroma cells may have a critical function in blood formation in the mouse spleen.

Blood ◽  
1989 ◽  
Vol 74 (7) ◽  
pp. 2391-2397 ◽  
Author(s):  
N Yanai ◽  
Y Matsuya ◽  
M Obinata

Abstract Mouse stromal cell lines (MSS lines) have been established from the spleens of newborn mice in culture at a low serum concentration. These MSS lines support the proliferation and differentiation of the erythroid progenitor cells from mouse fetal livers and bone marrow in a semisolid medium in the presence of erythropoietin. Larger colonies of over 1,000 benzidine-positive erythroid cells were developed from the fetal liver cells on the MSS cell layers after 6 days of incubation. These layers also support the maturation of the erythroid cells since the enucleation process of the latter was observed in large erythroid colonies. Metabolically active MSS cells are apparently required to support the proliferation and differentiation of the erythroid progenitor cells, because neither the MSS cells inactivated with fixation nor the conditioned media of MSS cells promoted the erythroid colony formation. These studies demonstrate that MSS lines specifically support the proliferation and differentiation of the erythroid progenitor cells in vitro and that stroma cells may have a critical function in blood formation in the mouse spleen.


Blood ◽  
1999 ◽  
Vol 94 (5) ◽  
pp. 1568-1577 ◽  
Author(s):  
Yoshihito Haseyama ◽  
Ken-ichi Sawada ◽  
Atsushi Oda ◽  
Kazuki Koizumi ◽  
Hina Takano ◽  
...  

Little is known about the physiologic role of phosphatidylinositol 3-kinase (PI-3K) in the development of erythrocytes. Previous studies have shown that the effects of the PI-3K inhibitor wortmannin on erythropoietin (EPO)-dependent cell lines differed depending on the cell type used. Wortmannin inhibited EPO-induced differentiation of some cell lines without affecting their proliferation; however, the EPO-induced proliferation of other cell lines was inhibited by wortmannin. In neither case were signs of apoptosis observed. We have previously reported that signaling in highly purified human colony forming units-erythroid (CFU-E), generated in vitro from CD34+ cells, differed from that in EPO-dependent cell lines. In the current study, we examined the effects of a more specific PI-3K inhibitor (LY294002) on human CFU-E. We found that LY294002 dose-dependently inhibits the proliferation of erythroid progenitor cells with a half-maximal effect at 10 μmol/L LY294002. LY294002 at similar concentrations also induces apoptosis of these cells, as evidenced by the appearance of annexin V–binding cells and DNA fragmentation. The steady-state phosphorylation of AKT at Ser-473 that occurs as a result of PI-3K activation was also inhibited by LY294002 at similar concentrations, suggesting that the effects of LY294002 are specific. Interestingly, the acceleration of apoptosis by LY294002 was observed in the presence or absence of EPO. Further, deprivation of EPO resulted in accelerated apoptosis irrespective of the presence of LY294002. Our study confirms and extends the finding that signaling in human primary cultured erythroid cells is significantly different from that in EPO-dependent cell lines. These data suggest that PI-3K has an antiapoptotic role in erythroid progenitor cells. In addition, 2 different pathways for the protection of primary erythroid cells from apoptosis likely exist: 1 independent of EPO that is LY294002-sensitive and one that is EPO-dependent and at least partly insensitive to LY294002.


Development ◽  
1990 ◽  
Vol 110 (2) ◽  
pp. 379-384
Author(s):  
O. Ohneda ◽  
N. Yanai ◽  
M. Obinata

Mouse stromal cell lines (FLS lines), established from the livers of 13-day gestation mouse fetus, supported the proliferation and differentiation of the erythroid progenitor cells from mouse fetal livers and bone marrow in a semisolid medium in the presence of erythropoietin. A large erythroid colony of over 1000 benzidine-positive erythroid cells was developed from a single erythroid progenitor cell on the FLS cell layer after 4 days of culture. When in close contact with the layer, the erythroid progenitor cells divided rapidly with an average generation time of 9.6 h and mature erythroid cells, including enucleated erythrocytes, were produced. The present studies demonstrate that the microenvironment created by the stromal cells can support the rapid expansion of erythropoietic cell population in the fetal liver of mice.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1159-1159
Author(s):  
Chris P. Miller ◽  
Songmao Zheng ◽  
C. Anthony Blau

Abstract Recombinant human erythropoietin (Epo) revolutionized the care of anemia in cancer. In light of emerging (albeit controversial) roles for Epo in supporting tumor growth, it may be useful to develop Epo-independent methods for regulating red blood cell production. Previous studies in this laboratory established that marrow transduced with conditional derivatives of fibroblast growth factor receptor-1 (F36VFGFR1) and the thrombopoietin receptor (F36VMpl) can support the chemical inducer of dimerization (CID)-dependent production of erythroid cells in transplanted mice. In the current study, we used human CD34+ cord blood (CB) cells to test whether CID-regulated red cell production might require collaboration between CID-initiated signals and those provided by Epo. CD34+ CB cells cultured in the absence of Epo did not proliferate and retained expression of the myeloid marker CD33. Epo (5U/mL) promoted proliferative expansion (66.2-fold in 12 days) and CD33 expression was lost as the cells differentiated to mature, glycophorin A+ erythroid cells (92.9 +/− 1.8%, n=3). Addition of a soluble human Epo receptor extracellular domain (shEpoR) at a concentration of 3ug/mL completely blocked Epo-dependent proliferation and similar to cells cultured without Epo, they retained expression of CD33. Addition of CID (100nM AP20187) to F36VMpl-transduced CD34+ CB cells in the absence of Epo promoted proliferative expansion (89.8-fold in 12 days) and differentiation as glycophorin A+ erythroid cells (77.2 +/− 4.8%, n=3). These CID responses were not significantly affected by the addition of shEpoR, as CID induced both mitogenic expansion (84.5 fold in 12 days) and differentiation as glycophorin A+ erythroid cells (74.2 +/− 6.7%, n=3) in the presence of concentrations of shEpoR that blocked Epo responses. These data suggest that F36VMpl does not require Epo signaling to support the proliferation and differentiation of human erythroid progenitor cells, and further define an Epo-independent method of erythroid cell production.


Blood ◽  
1999 ◽  
Vol 94 (5) ◽  
pp. 1568-1577 ◽  
Author(s):  
Yoshihito Haseyama ◽  
Ken-ichi Sawada ◽  
Atsushi Oda ◽  
Kazuki Koizumi ◽  
Hina Takano ◽  
...  

Abstract Little is known about the physiologic role of phosphatidylinositol 3-kinase (PI-3K) in the development of erythrocytes. Previous studies have shown that the effects of the PI-3K inhibitor wortmannin on erythropoietin (EPO)-dependent cell lines differed depending on the cell type used. Wortmannin inhibited EPO-induced differentiation of some cell lines without affecting their proliferation; however, the EPO-induced proliferation of other cell lines was inhibited by wortmannin. In neither case were signs of apoptosis observed. We have previously reported that signaling in highly purified human colony forming units-erythroid (CFU-E), generated in vitro from CD34+ cells, differed from that in EPO-dependent cell lines. In the current study, we examined the effects of a more specific PI-3K inhibitor (LY294002) on human CFU-E. We found that LY294002 dose-dependently inhibits the proliferation of erythroid progenitor cells with a half-maximal effect at 10 μmol/L LY294002. LY294002 at similar concentrations also induces apoptosis of these cells, as evidenced by the appearance of annexin V–binding cells and DNA fragmentation. The steady-state phosphorylation of AKT at Ser-473 that occurs as a result of PI-3K activation was also inhibited by LY294002 at similar concentrations, suggesting that the effects of LY294002 are specific. Interestingly, the acceleration of apoptosis by LY294002 was observed in the presence or absence of EPO. Further, deprivation of EPO resulted in accelerated apoptosis irrespective of the presence of LY294002. Our study confirms and extends the finding that signaling in human primary cultured erythroid cells is significantly different from that in EPO-dependent cell lines. These data suggest that PI-3K has an antiapoptotic role in erythroid progenitor cells. In addition, 2 different pathways for the protection of primary erythroid cells from apoptosis likely exist: 1 independent of EPO that is LY294002-sensitive and one that is EPO-dependent and at least partly insensitive to LY294002.


1994 ◽  
Vol 14 (4) ◽  
pp. 2266-2277 ◽  
Author(s):  
G D Longmore ◽  
P N Pharr ◽  
H F Lodish

If the env gene of spleen focus-forming virus (SFFV) is replaced by a cDNA encoding a constitutively active form of the erythropoietin receptor, EPO-R(R129C), the resultant recombinant virus, SFFVcEPO-R, induces transient thrombocytosis and erythrocytosis in infected mice. Clonogenic progenitor cell assays of cells from the bone marrow and spleens of these infected mice suggest that EPO-R(R129C) can stimulate proliferation of committed megakaryocytic and erythroid progenitors as well as nonerythroid multipotent progenitors. From the spleens of SFFVcEPO-R-infected mice, eight multiphenotypic immortal cell lines were isolated and characterized. These included primitive erythroid, lymphoid, and monocytic cells. Some expressed proteins characteristic of more than one lineage. All cell lines resulting from SFFVcEPO-R infection contained a mutant form of the p53 gene. However, in contrast to infection by SFFV, activation of PU.1 gene expression, by retroviral integration, was not observed. One cell line had integrated a provirus upstream of the fli-1 gene, in a location typically seen in erythroleukemic cells generated by Friend murine leukemia virus infection. This event led to increased expression of fli-1 in this cell line. Thus, infection by SFFVcEPO-R can induce proliferation and lead to transformation of nonerythroid as well as very immature erythroid progenitor cells. The sites of proviral integration in clonal cell lines are distinct from those in SFFV-derived lines.


2007 ◽  
Vol 82 (5) ◽  
pp. 2470-2476 ◽  
Author(s):  
Susan Wong ◽  
Ning Zhi ◽  
Claudia Filippone ◽  
Keyvan Keyvanfar ◽  
Sachiko Kajigaya ◽  
...  

ABSTRACT The pathogenic parvovirus B19 (B19V) has an extreme tropism for human erythroid progenitor cells. In vitro, only a few erythroid leukemic cell lines (JK-1 and KU812Ep6) or megakaryoblastoid cell lines (UT7/Epo and UT7/Epo-S1) with erythroid characteristics support B19V replication, but these cells are only semipermissive. By using recent advances in generating large numbers of human erythroid progenitor cells (EPCs) ex vivo from hematopoietic stem cells (HSCs), we produced a pure population of CD36+ EPCs expanded and differentiated from CD34+ HSCs and assessed the CD36+ EPCs for their permissiveness to B19V infection. Over more than 3 weeks, cells grown in serum-free medium expanded more than 800,000-fold, and 87 to 96% of the CD36+ EPCs were positive for globoside, the cellular receptor for B19V. Immunofluorescence (IF) staining showed that about 77% of the CD36+ EPCs were positive for B19V infection, while about 9% of UT7/Epo-S1 cells were B19V positive. Viral DNA detected by real-time PCR increased by more than 3 logs in CD36+ EPCs; the increase was 1 log in UT7/Epo-S1 cells. Due to the extensive permissivity of CD36+ EPCs, we significantly improved the sensitivity of detection of infectious B19V by real-time reverse transcription-PCR and IF staining 100- and 1,000-fold, respectively, which is greater than the sensitivity of UT7/Epo-S1 cell-based methods. This is the first description of an ex vivo method to produce large numbers of EPCs that are highly permissive to B19V infection and replication, offering a cellular system that mimics in vivo infection with this pathogenic human virus.


Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1576-1582 ◽  
Author(s):  
M Silva ◽  
D Grillot ◽  
A Benito ◽  
C Richard ◽  
G Nunez ◽  
...  

Abstract Erythropoietin (Epo), the hormone that is the principal regulator of red blood cell production, interacts with high-affinity receptors on the surface of erythroid progenitor cells and maintains their survival. Epo has been shown to promote cell viability by repressing apoptosis; however, the molecular mechanism involved is unclear. In the present studies we have examined whether Epo acts as a survival factor through the regulation of the bcl-2 family of apoptosis-regulatory genes. We addressed this issue in HCD-57, a murine erythroid progenitor cell line that requires Epo for proliferation and survival. When HCD-57 cells were cultured in the absence of Epo, Bcl-2 and Bcl-XL but not Bax were downregulated, and the cells underwent apoptotic cell death. HCD-57 cells infected with a retroviral vector encoding human Bcl-XL or Bcl-2 rapidly stopped proliferating but remained viable in the absence of Epo. Furthermore, endogenous levels of bcl-2 and bcl-XL were downregulated after Epo withdrawal in HCD-57 cells that remained viable through ectopic expression of human Bcl-XL, further indicating that Epo specifically maintains the expression of bcl-2 and bcl-XL. We also show that HCD-57 rescued from apoptosis by ectopic expression of Bcl-XL can undergo erythroid differentiation in the absence of Epo, demonstrating that a survival signal but not Epo itself is necessary for erythroid differentiation of HCD-57 progenitor cells. Thus, we propose a model whereby Epo functions as a survival factor by repressing apoptosis through Bcl-XL and Bcl-2 during proliferation and differentiation of erythroid progenitors.


Blood ◽  
1994 ◽  
Vol 83 (10) ◽  
pp. 2844-2850 ◽  
Author(s):  
N Yanai ◽  
C Sekine ◽  
H Yagita ◽  
M Obinata

Abstract Adhesion molecules are required for development of hematopoietic stem and progenitor cells in the respective hematopoietic microenvironments. We previously showed that development of the erythroid progenitor cells is dependent on their direct adhesion to the stroma cells established from the erythropoietic organs. In this stroma-dependent erythropoiesis, we examined the role of adhesion molecules in erythropoiesis by blocking antibodies. The development of the erythroid cells on stroma cells was inhibited by anti-very late activation antigen-4 (VLA-4 integrin) antibody, but not by anti-VLA-5 antibody, although the erythroid cells express both VLA-4 and VLA-5. Whereas high levels of expression of vascular cell adhesion molecule-1 (VCAM-1) and fibronectin, ligands for VLA-4, were detected in the stroma cells, the adhesion and development of the erythroid progenitor cells were partly inhibited by the blocking antibody against VCAM-1. VLA-5 and fibronectin could mediate adhesion of the erythroid progenitor cells to the stromal cells, but the adhesion itself may not be sufficient for the stroma-supported erythropoiesis. The stromal cells may support erythroid development by the adhesion through a new ligand molecule(s) for VLA-4 in addition to VCAM-1, and such collaborative interaction may provide adequate signaling for the erythroid progenitor cells in the erythropoietic microenvironment.


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