scholarly journals Erythropoiesis in ha/ha and sph/sph mice, mutants which produce spectrin-deficient erythrocytes

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 646-651 ◽  
Author(s):  
D Brookoff ◽  
L Maggio-Price ◽  
S Bernstein ◽  
L Weiss
Keyword(s):  
Bone Marrow ◽  
Membrane Protein ◽  
Stromal Cells ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Plasma Clot ◽  
Dark Cells ◽  
Erythroid Precursors ◽  
The Status ◽  
Deficient Mice

In order to characterize chronically accelerated erythropoiesis, we studied the ultrastructure of bone marrow and spleen of ha/ha and sph/sph mice, two mutants with profound hemolytic anemia secondary to deficiency of the erythrocyte membrane protein spectrin. The marrows and spleens of both varieties were extremely erythropoietic and were without histological abnormalities directly related to spectrin deficiency. Erythropoiesis was consistently associated with distinctive, dark branched cells which constituted large proportions of the stroma of the mutant spleens and marrow. These dark cells were not present in untreated and acutely bled controls. Plasma clot assays for erythroid progenitors revealed that CFU-E concentrations in the mutant marrows were significantly increased over those in untreated controls while BFU-E concentrations were approximately half. In addition, mutant CFU-E often gave rise to abnormal appearing colonies. Spectrin, though crucial to erythrocyte function is probably not important to the process of erythroid differentiation and maturation. The status of erythroid precursors in the marrows of the spectrin deficient mice is similar to that of mice subjected to an acute bleed. The divergent changes in CFU-E and BFU-E may indicate that these two cells play different roles in accelerated erythropoiesis. The dark cells that we describe are similar to stromal cells observed in models of the early stages of erythropoiesis.

scholarly journals Erythropoiesis in ha/ha and sph/sph mice, mutants which produce spectrin-deficient erythrocytes

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 646-651 ◽  
Author(s):  
D Brookoff ◽  
L Maggio-Price ◽  
S Bernstein ◽  
L Weiss
Keyword(s):  
Bone Marrow ◽  
Membrane Protein ◽  
Stromal Cells ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Plasma Clot ◽  
Dark Cells ◽  
Erythroid Precursors ◽  
The Status ◽  
Deficient Mice

Abstract In order to characterize chronically accelerated erythropoiesis, we studied the ultrastructure of bone marrow and spleen of ha/ha and sph/sph mice, two mutants with profound hemolytic anemia secondary to deficiency of the erythrocyte membrane protein spectrin. The marrows and spleens of both varieties were extremely erythropoietic and were without histological abnormalities directly related to spectrin deficiency. Erythropoiesis was consistently associated with distinctive, dark branched cells which constituted large proportions of the stroma of the mutant spleens and marrow. These dark cells were not present in untreated and acutely bled controls. Plasma clot assays for erythroid progenitors revealed that CFU-E concentrations in the mutant marrows were significantly increased over those in untreated controls while BFU-E concentrations were approximately half. In addition, mutant CFU-E often gave rise to abnormal appearing colonies. Spectrin, though crucial to erythrocyte function is probably not important to the process of erythroid differentiation and maturation. The status of erythroid precursors in the marrows of the spectrin deficient mice is similar to that of mice subjected to an acute bleed. The divergent changes in CFU-E and BFU-E may indicate that these two cells play different roles in accelerated erythropoiesis. The dark cells that we describe are similar to stromal cells observed in models of the early stages of erythropoiesis.

scholarly journals Bok Promotes Erythropoiesis in a Mouse Model of Myelodysplastic Syndrome

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 922-922
Author(s):  
Seong-Ho Kang ◽  
Oscar Perales ◽  
Michael Michuad ◽  
Samuel G. Katz
Keyword(s):  
Bone Marrow ◽  
Mouse Model ◽  
Er Stress ◽  
Hemoglobin Concentration ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Erythroid Progenitor ◽  
Mean Cell Volume ◽  
The Unfolded Protein Response ◽  
Deficient Mice

Abstract BCL-2 Ovarian Killer (BOK) is a pro-apoptotic member of the BCL-2 family of proteins best characterized for its putative ability to induce apoptosis in response to Endoplasmic Reticulum (ER) stress, when stabilized from ER-associated degradation (ERAD). Although ER stress appropriately activates the unfolded protein response (UPR) in BOK-disrupted cells, as measured by PERK and eIF2-alpha phosphorylation, downstream effector signaling, including ATF4 and CHOP, is defective. A functional role for BOK as a tumor suppressor is suggested by its genetic location in one of the 20 most frequent, focally deleted chromosomal regions across all human cancers. To evaluate the consequences of BOK loss in the pathogenesis of myelodysplasia (MDS) and Acute Myeloid Leukemia (AML), we used the Nup98-HoxD13 (NHD13) transgenic mouse model of MDS/AML. In this model, both overexpression of anti-apoptotic BCL-2 and deletion of pro-apoptotic PUMA rescue cytopenias, but surprisingly delay progression to AML. In contrast, AML developed in 36.7% of NHD13 mice lacking BOK between the age of 8 and 13 months with a similar overall survival to the NHD13 mice. However, the loss of BOK exacerbated the anemia of the NHD13 mice, which raised a potential connection between BOK and the regulation of erythropoiesis in cells experiencing stress from the NHD13 translocation. NHD13 mice deficient for BOK exhibited significantly lower hemoglobin (Hb), lower mean cell hemoglobin concentration (MCHC) and higher mean cell volume (MCV) than NHD13 mice, whereas other lineages were unaffected. Mouse colony forming unit assays revealed there is a decreased amount of erythroid progenitor stem cells (BFU-E) in the bone marrow of NHD13-transgenic/BOK-deficient mice, which hinted at a diminished ability to produce RBCs in the absence of BOK. Isolation of various stages of erythroid progenitors in the bone marrow by CD44/TER119 FACS sorting revealed that both NHD13 and NHD13-transgenic/BOK-deficient mice have an increase in proerythroblasts relative to more mature red blood cells. Preliminary RT-QPCR analysis shows decreased expression of UPR components in the RBC progenitors of both BOK-deficient and NHD13-transgenic/BOK-deficient mice. Interestingly, CHOP is not only a component of the UPR, but also an erythropoietin target gene necessary for erythroid differentiation. These results suggest that in addition to its pro-apoptotic function, BOK may have other regulatory roles within the cell, and specifically a role in regulating erythropoiesis when certain RBC progenitors experience ER stress. Disclosures Katz: Gene-in-Cell: Equity Ownership.

scholarly journals Ineffective Erythropoiesis inβ-Thalassemia

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Jean-Antoine Ribeil ◽  
Jean-Benoit Arlet ◽  
Michael Dussiot ◽  
Ivan Cruz Moura ◽  
Geneviève Courtois ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Premature Death ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Ineffective Erythropoiesis ◽  
Molecular Defects ◽  
Erythroid Precursors ◽  
Underlying Mechanisms

In humans,β-thalassemia dyserythropoiesis is characterized by expansion of early erythroid precursors and erythroid progenitors and then ineffective erythropoiesis. This ineffective erythropoiesis is defined as a suboptimal production of mature erythrocytes originating from a proliferating pool of immature erythroblasts. It is characterized by (1) accelerated erythroid differentiation, (2) maturation blockade at the polychromatophilic stage, and (3) death of erythroid precursors. Despite extensive knowledge of molecular defects causingβ-thalassemia, less is known about the mechanisms responsible for ineffective erythropoiesis. In this paper, we will focus on the underlying mechanisms leading to premature death of thalassemic erythroid precursors in the bone marrow.

scholarly journals SFL 23.6: a monoclonal antibody reactive with CFU-E, erythroblasts, and erythrocytes

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 522-526 ◽  
Author(s):  
AD Gupta ◽  
MK Samoszuk ◽  
T Papayannopoulou ◽  
G Stamatoyannopoulos
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Cell Sorting ◽  
Antigenic Determinant ◽  
Mononuclear Cells ◽  
Bone Marrow Cells ◽  
Fetal Liver ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Erythroid Precursors

Abstract A cytotoxic (IgG2b) monoclonal antibody (McAb) for a novel erythroid differentiation antigen was generated by hyperimmunizing young mice with mononuclear cells obtained from livers of 20- to 22-week-old fetuses. This McAb, designated SFL 23.6, shows an extremely well- defined reactivity with the cells of the erythroid lineage at all stages of maturation as evident from the labeling of morphologically identifiable erythroid precursors and of erythrocytes present in peripheral blood, bone marrow, and fetal liver, and from its reactivity with culture-derived erythroblasts. The nonerythroid cells present in these and other tissue preparations were not labeled by SFL 23.6. The erythroid lineage specificity of McAb SFL 23.6 was confirmed by a cell- sorting experiment in which 97% of the cells in the fluorescent fraction sorted from SFL 23.6-treated bone marrow cells were erythroid precursors at various stages of maturation. Complement-mediated cytotoxicity and progenitor cell-sorting experiments showed that most (greater than 90%) of the late erythroid progenitors (CFU-E) and only a small proportion of the early erythroid progenitors (BFU-E) express the antigenic determinant identified by SFL 23.6. The myeloid progenitors (CFU-GM) and multilineage progenitors (CFU-GEMM) were negative for the SFL 23.6 antigenic determinant. The antigen recognized by SFL 23.6 has not been determined as yet. Because of the pattern of its reactivity and its dependence on sialic acid residues, the possibility of its relationship to glycophoria A was entertained. However, previous work using antiglycophorin McAbs (R-10) has shown that this determinant is not expressed in CFU-E. Therefore, among the erythroid lineage-specific McAbs described thus far, SFL 23.6 is unique in its reactivity with CFU- E and the mature erythron. Reagents with such specificity may be useful in studies of erythroid differentiation and commitment.

scholarly journals SFL 23.6: a monoclonal antibody reactive with CFU-E, erythroblasts, and erythrocytes

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 522-526
Author(s):  
AD Gupta ◽  
MK Samoszuk ◽  
T Papayannopoulou ◽  
G Stamatoyannopoulos
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Cell Sorting ◽  
Antigenic Determinant ◽  
Mononuclear Cells ◽  
Bone Marrow Cells ◽  
Fetal Liver ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Erythroid Precursors

A cytotoxic (IgG2b) monoclonal antibody (McAb) for a novel erythroid differentiation antigen was generated by hyperimmunizing young mice with mononuclear cells obtained from livers of 20- to 22-week-old fetuses. This McAb, designated SFL 23.6, shows an extremely well- defined reactivity with the cells of the erythroid lineage at all stages of maturation as evident from the labeling of morphologically identifiable erythroid precursors and of erythrocytes present in peripheral blood, bone marrow, and fetal liver, and from its reactivity with culture-derived erythroblasts. The nonerythroid cells present in these and other tissue preparations were not labeled by SFL 23.6. The erythroid lineage specificity of McAb SFL 23.6 was confirmed by a cell- sorting experiment in which 97% of the cells in the fluorescent fraction sorted from SFL 23.6-treated bone marrow cells were erythroid precursors at various stages of maturation. Complement-mediated cytotoxicity and progenitor cell-sorting experiments showed that most (greater than 90%) of the late erythroid progenitors (CFU-E) and only a small proportion of the early erythroid progenitors (BFU-E) express the antigenic determinant identified by SFL 23.6. The myeloid progenitors (CFU-GM) and multilineage progenitors (CFU-GEMM) were negative for the SFL 23.6 antigenic determinant. The antigen recognized by SFL 23.6 has not been determined as yet. Because of the pattern of its reactivity and its dependence on sialic acid residues, the possibility of its relationship to glycophoria A was entertained. However, previous work using antiglycophorin McAbs (R-10) has shown that this determinant is not expressed in CFU-E. Therefore, among the erythroid lineage-specific McAbs described thus far, SFL 23.6 is unique in its reactivity with CFU- E and the mature erythron. Reagents with such specificity may be useful in studies of erythroid differentiation and commitment.

scholarly journals Stromal cell-associated erythropoiesis

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1418-1426 ◽  
Author(s):  
S Tsai ◽  
CA Sieff ◽  
DG Nathan
Keyword(s):  
Bone Marrow ◽  
Extracellular Matrix ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Culture Medium ◽  
Serum Proteins ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Erythroid Progenitors ◽  
Culture Dish

Abstract A novel cover slip-transfer culture system was designed to study the functional roles of stromal cells in hemopoiesis, particularly erythropoiesis. Human bone marrow stromal cell colonies were allowed to develop on small glass cover slips in liquid medium. The cover slips, along with the stromal cell colonies and progenitors attached to them were then transferred to a new tissue culture dish and overlaid with methylcellulose culture medium. No exogenous colony-stimulating factors except erythropoietin were supplied. Large erythroid bursts, comprising multiple subcolonies, developed on the stromal cells. In order to determine if stromal fibroblasts together with erythropoietin and serum proteins could support erythroid development, human bone marrow cells depleted of monocytes, macrophages, and T lymphocytes were allowed to adhere to monolayers of a homogeneous fibroblastoid human stromal cell strain ST-1 grown on cover slips. The cover slips were then washed to remove nonadherent cells, transferred to a new culture dish, and overlaid with methylcellulose culture medium containing fetal calf serum and erythropoietin. In this modified system as well, primitive erythroid progenitors migrated extensively on and within the stroma to form huge colonies of hemoglobinized erythroblasts that proceeded to enucleate. Our results indicate that (1) ST-1 cells together with serum proteins and erythropoietin can support the development of large erythroid bursts; (2) erythroid progenitors and precursors adhere to and migrate on and within the extracellular matrix elaborated by ST-1 cells; (3) erythroid progenitors are more adherent to the ST-1 cells or the extracellular matrix than are the more mature cells and possibly the myeloid progenitors.

scholarly journals Decreased PGC1β expression results in disrupted human erythroid differentiation, impaired hemoglobinization and cell cycle exit

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taha Sen ◽  
Jun Chen ◽  
Sofie Singbrant
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Mitochondrial Function ◽  
Iron Homeostasis ◽  
Erythroid Differentiation ◽  
Refractory Anemia ◽  
Cell Cycle Exit ◽  
Erythroid Progenitors ◽  
Hematopoietic Stem ◽  
Terminal Erythroid Differentiation

AbstractProduction of red blood cells relies on proper mitochondrial function, both for their increased energy demands during differentiation and for proper heme and iron homeostasis. Mutations in genes regulating mitochondrial function have been reported in patients with anemia, yet their pathophysiological role often remains unclear. PGC1β is a critical coactivator of mitochondrial biogenesis, with increased expression during terminal erythroid differentiation. The role of PGC1β has however mainly been studied in skeletal muscle, adipose and hepatic tissues, and its function in erythropoiesis remains largely unknown. Here we show that perturbed PGC1β expression in human hematopoietic stem/progenitor cells from both bone marrow and cord blood results in impaired formation of early erythroid progenitors and delayed terminal erythroid differentiation in vitro, with accumulations of polychromatic erythroblasts, similar to MDS-related refractory anemia. Reduced levels of PGC1β resulted in deregulated expression of iron, heme and globin related genes in polychromatic erythroblasts, and reduced hemoglobin content in the more mature bone marrow derived reticulocytes. Furthermore, PGC1β knock-down resulted in disturbed cell cycle exit with accumulation of erythroblasts in S-phase and enhanced expression of G1-S regulating genes, with smaller reticulocytes as a result. Taken together, we demonstrate that PGC1β is directly involved in production of hemoglobin and regulation of G1-S transition and is ultimately required for proper terminal erythroid differentiation.

scholarly journals Effects of actinomycin D in vivo on murine erythroid stem cells

Blood ◽  
1978 ◽  
Vol 51 (5) ◽  
pp. 957-969 ◽  
Author(s):  
KS Zuckerman ◽  
R Sullivan ◽  
PJ Quesenberry
Keyword(s):  
Stem Cells ◽  
Low Dose ◽  
Actinomycin D ◽  
Erythroid Differentiation ◽  
Plasma Clot ◽  
Differentiated Cells ◽  
Erythroid Precursors

Abstract Low-dose actinomycin D (Acto) selectively suppresses murine erythropoiesis without decreasing erythropoietin (Ep) production. We used the plasma clot system to determine the stage of erythroid differentiation at which this inhibition occurs. Late erythroid precursors, CFU-E, and less differentiated committed erythroid stem cells, BFU-E, were assayed in CF1 mice given Acto 75–82 microgram/kg/day or saline subcutaneously for 5 days. We also assayed pluripotent (CFU-S) and committed granulocyte-monocyte (CFU-C) stem cells. Reticulocytes and marrow and spleen nucleated erythroid precursors were decreased by 99% in the Acto-treated mice; tibial marrow CFU-E were decreased by 97% and splenic CFU-E by 99%. Tibial BFU- E were not decreased by Acto, although there was a 66% diminution in splenic BFU-E. Acto increased tibial CFU-S, but splenic CFU-S and tibial and splenic CFU-C were unchanged. Thus Acto inhibits erythropoiesis by suppressing the ability of immediate committed erythroid precursors of CFU-E or CFU-E themselves to differentiate further in response to Ep. Acto does not affect survival or proliferation of the less differentiated cells--CFU-C, CFU-S, and marrow BFU-E. The suppression of splenic BFU-E in Acto-treated mice may indicate that marrow and splenic BFU-E are basically different stem cells. Alternatively, Acto treatment may impair migration of BFU-E from marrow to spleen.

L-Carnitine and Apoptosis in Thalassemia Major Patients.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3767-3767
Author(s):  
Ali Taher ◽  
H. Seoud ◽  
A. Ibrahim ◽  
H. Gabre ◽  
I. Youssry Ibrahim ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Enzyme Immunoassay ◽  
Gel Electrophoresis ◽  
Large Scale ◽  
Early Stage ◽  
Thalassemia Major ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Erythroid Progenitors ◽  
Erythroid Precursors

Abstract Background and Objectives: Thalassemia major patients suffer from severe anemia due to intramedullary hemolysis of erythroid progenitors. Depending on the severity of their disease, thalassemic patients exhibit different patterns of apoptosis. In cases of β-thalassemia major, apoptosis appears to be greatly enhanced in the early-stage erythroid precursors in the bone marrow and it is considered to be the machinery via which ineffective erythropoiesis develops. L-Carnitine is a butyrate derivative found to strongly reduce apoptosis in different diseases. We investigated the effect of oral L-carnitine therapy on apoptosis in thalassemia major patients. Methods: eighteen Thalassemia major patients were included. Detection of apoptosis was done by Photometric enzyme immunoassay (Elisa) and agarose gel electrophoresis before and after 6 months oral therapy with L-Carnitine (50mg/kg/day). Results: The mean age was 12.2±6.6 years. All patients tolerated L-carnitine with no side effects. A significant decrease of apoptosis rates in the erythroid precursors in the bone marrow of studied cases was noted after therapy by. The enrichment factor measured by the photometric enzyme immunoassay dropped from 3.65±1.338 before therapy to 1.60±0.65 after therapy (p=0.005). A positive ladder pattern reflecting apoptosis on agarose gel electrophoresis was detected in 88.9% of cases prior to treatment (figure 1) versus 11.1% after therapy (figure 2) (p=0.006). Patients also had significant decrease in the frequency of transfusions and increase in the pre-transfusion hemoglobin levels after therapy. These results were found to significantly correlate with the reduction in apoptosis rates (p=0.006, r = 0.543 and p=0.027 &r = −0.7762 respectively). Conclusion: Apoptosis plays a major role in the underlying pathophysiology of anemia in thalassemic patients. L-Carnitine seems to be a good modulator of apoptotic processes in such patients leading to decreased rates of programmed erythroblast death and general improvement of the disease condition. Further large-scale studies are needed to evaluate the overall role of L-Carnitine in the management of these patients. Figure Figure

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