scholarly journals Red blood cells derived from peripheral blood and bone marrow CD34+ human haematopoietic stem cells are permissive to Plasmodium parasites infection

2013 ◽  
Vol 108 (6) ◽  
pp. 801-803 ◽  
Author(s):  
Carmen Fernandez-Becerra ◽  
Joel Lelievre ◽  
Mireia Ferrer ◽  
Nuria Anton ◽  
Richard Thomson ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Red Blood Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Haematopoietic Stem Cells

scholarly journals A review of the treatment landscape in paroxysmal nocturnal haemoglobinuria: where are we now and where are we going?

2020 ◽  
Vol 1 ◽  
pp. 263300402095934
Author(s):  
Morag Griffin ◽  
Richard Kelly ◽  
Alexandra Pike
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Life Expectancy ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Treatment Options ◽  
White Blood Cells ◽  
Paroxysmal Nocturnal Haemoglobinuria ◽  
Complement Cascade ◽  
Future Treatments

Paroxysmal nocturnal haemoglobinuria (PNH) is an ultra-orphan disease, which until 15 years ago had limited treatment options. Eculizumab, a monoclonal antibody that inhibits C5 in the terminal complement cascade, has revolutionised treatment for this disease, near normalising life expectancy and improving quality of life for patients. The treatment landscape of PNH is now evolving, with ravulizumab a second longer acting intravenous C5 inhibitor now licenced by the FDA and EMA. With different therapeutic targets in the complement cascade and difference modalities of treatment, including subcutaneous, oral and intravenous therapies being developed, increasing independence for patients and reducing healthcare requirements. This review discusses the current and future therapies for PNH. Lay summary Review of current and future treatments for patients with Paroxysmal Nocturnal Haemoglobinuria What is Paroxysmal Nocturnal Haemoglobinuria? Paroxysmal nocturnal haemoglobinuria (PNH) is a very rare disease. It arises from PNH stem cells in the bone marrow. In a normal bone marrow these are inactive; however, if there has been a problem in the bone marrow, the PNH stem cells can expand and make PNH red blood cells, white blood cells and platelets. The problem with these cells is that they lack the cell surface markers that usually protect them. Red blood cells are broken down in the circulation rather than the spleen, which gives rise to PNH symptoms such as abdominal pain, difficulty swallowing, erectile dysfunction and red or black urine (known as haemoglobinuria). The white blood cells and platelets are ‘stickier’ increasing the risk of blood clots. Previously life expectancy was reduced as there were limited treatment options available. What was the aim of this review? To provide an overview of current and future treatment options for PNH Which treatments are available? • Eculizumab is an treatment given through a vein (intravenous) every week for 5 weeks then every 2 weeks after this, and has been available for 13 years, improving life expectancy to near normal. • Ravulizumab is a newer intravenous treatment similar to eculizumab but is given every 8 weeks instead of every 2 weeks. In clinical studies it was comparable with eculizumab. • Future Treatments - There is new research looking at different methods of treatment delivery, including injections under the skin (subcutaneous) that patients can give themselves, treatments taken by mouth (oral) or a combination of an intravenous and oral treatment for those patients who are not optimally controlled on eculizumab or ravulizumab. What does this mean? PNH is now treatable. For years, the only drug available was eculizumab, but now different targets and drug trials are available. Ravulizumab is currently the only second licenced product available, in USA and Europe, there are other medications active in clinical trials. Why is this important? The benefit for patients, from treatment every 2 weeks to every 8 weeks is likely to be improved further with the development of these new treatments, providing patients with improved disease control and independence. As we move into an era of more patient-friendly treatment options, the PNH community both physicians and patients look forward to new developments as discussed in this article.

Sparc Is Dispensable for Murine Hematopoiesis, Despite Its Suspected Role in 5q- Myelodysplastic Syndrome

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4822-4822
Author(s):  
Kavitha Siva ◽  
Pekka Jaako ◽  
Kenichi Miharada ◽  
Emma Rörby ◽  
Mats Ehinger ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Knockout Mice ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Lethal Dose ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Normal Peripheral Blood ◽  
Expression Levels

Abstract Abstract 4822 Hematopoiesis is a complex process where a limited number of stem cells give rise to all mature blood cells. It involves interplay of several factors, many of which are yet to be identified. In a search for novel regulators of hematopoiesis, we chose to study SPARC (Secreted Protein Acidic and Rich in Cysteine, also known as Osteonection and BM40) because it is downregulated upon hematopoietic differentiation (Bruno et al., Mol Cell Biol, 2004) and might therefore play a role in the regulation of hematopoietic stem cells (HSC). SPARC is a matricellular protein that forms a major component of bone and is ubiquitously expressed in a variety of tissues. It is the founding member of a family of SPARC-like proteins. Several publications have indicated an important role for SPARC in hematopoiesis. In particular – knockdown of SPARC in zebrafish embryos resulted in an altered number of circulating blood cells, and a knockout mouse model showed thrombocytopenia and reduced erythroid colony formation. We carried out an in depth phenotypic and functional analysis of the hematopoietic system of SPARC knockout mice; using it as a model to gain insight into the role of SPARC in hematopoiesis. These mice are viable and fertile but show severe osteopenia and age-onset cataract at about six months of age. They also show an altered response to tumour growth and wound healing. We used mice (129SVJ background) (Gilmour et al. EMBO, 1998) that were less than six months old. These mice had normal peripheral blood counts and the bone marrow and spleen showed no alterations in morphology or cellularity. A detailed phenotypic analysis of precursors within the bone marrow showed no significant differences in myelo-erythroid precursors as compared to wild types (n=6). Though in vitro, the precursors showed lower ability to form BFU-E (n=5, p=0.048). In transplantations of lethally irradiated recipient mice, SPARC knockout cells gave rise to multi-lineage long-term reconstitution. Also, when competed with wild type cells, they provided reconstitution as well as their wild type counterparts. When SPARC knockout mice (n=8) were transplanted with wild type cells, there was normal reconstitution, indicating that a SPARC deficient niche can fully support normal hematopoiesis. We also tested if SPARC deficient mice respond differently to hematopoietic stress. We subjected mice (n=7) to sub lethal dose of irradiation and to experimentally induced anemia (n=7) and followed recovery by analyzing peripheral blood counts. In both SPARC knockouts and wild type mice, the blood counts recovered in a similar fashion. In conclusion, we find that SPARC is dispensable for murine hematopoiesis. It is possible that there are compensatory mechanisms involving other members of the SPARC family that ultimately lead to normal hematopoiesis in the murine model. In humans, SPARC maps to the deleted region in 5q MDS and has been reported to be 71 % down regulated in patient samples (Lehmann et al. Leukemia, 2007). It is the most prominent gene that is up regulated in response to lenalidomide, a drug that inhibits the malignant clone (Pellagatti et al. PNAS, 2007). SPARC is thus increasingly speculated to be involved in the pathophysiology of this hematopoetic disease. We analysed the expression levels of SPARC mRNA in the hematopoietic stem/progenitor cell compartment and found high expression levels in the CD34+ fraction of human cord blood cells. In contrast, there is very low level of SPARC expression in all compartments of murine HSCs. Therefore SPARC function may play a more important role in human hematopoiesis than in murine blood cell regulation. Disclosures: No relevant conflicts of interest to declare.

Homeostatic Role of the Krüppel-Like Factor 4 (KLF4) in Proliferation and Differentiation of Primitive Hematopoietic Progenitor Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1497-1497 ◽  
Author(s):  
Chun Shik Park ◽  
Takeshi Yamada ◽  
H. Daniel Lacorazza
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Progenitor Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Proliferative Potential ◽  
Dependent Manner ◽  
Hematopoietic Stem ◽  
Deficient Mice

Abstract Abstract 1497 Poster Board I-520 KLF4 is a tumor suppressor in the gastrointestinal tract known to induce cell cycle arrest in a cell context dependent manner. We recently reported that KLF4 maintains quiescence of T lymphocytes downstream of T-cell receptor signaling (Yamada et al., Nature Immunology, 2009). The role of KLF4 in reprogramming adult somatic cells into pluripotent stem cells along with Oct3/4, c-Myc and Sox2 suggests that KLF4 restricts proliferation of undifferentiated cells. In spite of a redundant role of KLF4 in fetal liver hematopoietic stem cells (HSC), its role in the maintenance of adult bone marrow HSCs has not been studied yet. To study the role of KLF4 in the hematopoietic system we used gain- and loss-of-function mouse models. Retroviral transfer of KLF4 into wild type bone marrow (BM) cells led to significant reduction of colony forming units (CFU) in methylcellulose cultures due to increased apoptosis and lower proliferation. Then, Mx1-Cre was used to induce deletion of Klf4-floxed mice by polyI:C administration. Analysis of peripheral blood cells up to 6-9 months post polyI:C administration showed significant reduction of monocytes, as previously reported, and expansion of CD8+CD44+ T cells due to their increased proliferative potential. BM cells from Klf4-deficient mice exhibited increased number of myeloid progenitor cells measured by flow cytometry (Lin-Sca-1-c-kit+FcRII/III+CD34+ cells), CFU and CFU-S8. Cytoablation with 5-fluorouracil (5-FU) showed lower nadir of peripheral white blood cells in Klf4-deficient mice compared to control mice. In spite of normal multilineage reconstitution in BM transplants experiments, competitive reconstitution with Klf4-deficient and normal BM cells resulted in reduced contribution of Klf4-deficient cells to peripheral blood, likely due to homing and proliferative differences. Collectively, our data shows that KLF4 has an important role in function of hematopoietic stem and progenitor cells. Disclosures: No relevant conflicts of interest to declare.

Viability in Late Stages of Ex Vivo Erythropoiesis Is Enhanced by Increased Cell Density

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4748-4748
Author(s):  
Daniela Boehm ◽  
Mohamed Al-Rubeai ◽  
William G Murphy
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Red Blood Cells ◽  
Cell Density ◽  
Late Stage ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Ex Vivo ◽  
Cd34 Cells ◽  
Late Stages

Abstract Erythropoiesis is one of the body’s most productive cell production processes yielding 2×1011 new red cells from hematopoietic stem cells (HSCs) of the bone marrow every day. Intensive research has focused on mimicking this process ex vivo through application of various growth factor combinations or co-culture with stromal cells. To develop a scalable and reproducible system for large scale production of red blood cells we have investigated in vitro erythropoiesis of peripheral blood derived CD34+ cells with primary focus on the impact of the microenvironment on the process. The influence of cultivation conditions on expansion of erythroid progenitor cells and their terminal differentiation to mature red blood cells were studied in stroma-free liquid culture supplemented with stem cell factor (SCF), interleukin-3 (IL-3) and erythropoietin (EPO). Peripheral blood derived CD34+ cells were expanded by more than 105 fold over a 3 week period. This degree of expansion has only been achieved previously for CD34+ cells derived from more potent stem cell sources such as cord blood, bone marrow and G-CSF mobilized peripheral blood (Giarratana et al, Nat Biotechnol 2005). The natural environment of human erythropoiesis, the bone marrow, is a very crowded milieu where hematopoietic precursors and other cells are packed in close proximity. Cell crowdedness was found to have significant influences on ex vivo erythropoiesis. Cell density per surface area rather than cell concentration per media volume determined cell expansion during exponential growth where more crowded cells showed reduced overall expansion. In cultures inoculated at 4×105 cells/ml (2.1×105 cells/cm2) increasing cell density per area (i.e. decreasing surface area to volume ratio) 4fold (to 8.4×105 cells/cm2) resulted in 35±12% reduction of total expansion (p<0.05, unpaired Student’s t-test). While 4fold increase of cell density in cultures seeded at 1×106 cells/ml (from 5.3×105 cells/cm2 to 2.1×106 cells/cm2) reduced overall expansion by 51±9% (p<0.01). In late stage erythropoiesis, however, when cells had become arrested in G1 and no longer proliferated, cell density was seen to enhance cell viability. Dilution series of late stage erythroblasts showed that although cell viability gradually decreased over a 14 day cultivation period the decreasing rate was lower in cells cultivated at higher density as shown in the Figure. Enhanced viability in crowded culture conditions could reflect the cells’ dependency on direct cell-cell interactions as found in the marrow environment. Cultures grown to high cell densities of 2–3×106 cells/cm2 showed higher maturation efficiency than previously obtained in this cultivation set-up with more than 80% of cells being CD71-/GpA+. Enucleation yields of up to 45% were achieved indicating a significant amount of terminal maturation to red blood cells. Efficient maturation and particularly enucleation have in many cases been found to be dependent on or improved by interactions with feeder cells or macrophages (Fujimi et al, Int J Hematol 2008). Keeping erythroid cells at high densities during late stages of erythropoiesis possibly helps to mimic their in vivo environment, thus allowing for better survival and efficient terminal maturation without the need for co-culture with other cells. Figure Figure

scholarly journals THE TYPE OF PHAGOCYTIC CELL AND ITS RELATIVE PROPORTIONS IN HUMAN BONE MARROW AND SPLEEN, AS IDENTIFIED BY THE SUPRAVITAL TECHNIQUE, WITH SPECIAL REFERENCE TO PERNICIOUS ANEMIA

1926 ◽  
Vol 43 (3) ◽  
pp. 289-296 ◽  
Author(s):  
Charles A. Doan
Keyword(s):  
Bone Marrow ◽  
Red Blood Cells ◽  
Special Reference ◽  
Pernicious Anemia ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Phagocytic Cell ◽  
Blood Picture ◽  
Nucleated Red Blood Cells ◽  
Marked Tendency

In general, there is a reversal of the normal in the ratio of clasmatocytes in the spleen to clasmatocytes in the bone marrow in pernicious anemia, with a marked tendency toward the phagocytosis of young, immature, nucleated red blood cells in the bone marrow. The peripheral blood picture suggests that these cells had never been in circulation. The observations made do not indicate that the spleen takes any directly active part in an increased destruction of blood in pernicious anemia.

The Therapeutic Effect of Umbilical Mesenchymal Stem Cells Injected Directly Into Medullary Cavity of Ilium to Treat Refractory Aplastic Anemia and Bone Marrow Fibrosis,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3226-3226
Author(s):  
Zhuanzhen Zheng ◽  
Zhenhua Qiao ◽  
Wenliang Chen ◽  
Rong Gong ◽  
Yalin Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Red Blood Cells ◽  
Aplastic Anemia ◽  
Blood Cells ◽  
Medullary Cavity ◽  
Bone Marrow Fibrosis ◽  
Routine Therapy ◽  
Marrow Fibrosis

Abstract Abstract 3226 Objective To evaluate mesenchymal stem cells(MSCs) combination with routine therapy to treat refractory aplastic anemia and bone marrow fibrosis, observe the course of the hematopoitic reconstitution and evaluate the security and curative effect. Methods 12 primary myelofibrosis and 19 chronic aplastic anemia patients who had all accepted routine therapy more than 6 months,because of pathogenetic condition, they needed infusing constituent blood such as at least condensed red blood cells 6 units and platelet 4 units per months, and despite this, whole blood cells counts were very lower. Those patients all had intermittent dizzy, fatigue, bad appetite and purpura. Because of age, complication, and psychological reasons, they refused Allogenic stem cell transplantation. So besides routine therapy, they received umbilical MSCs 1×107, every two weeks one time, those cells were injected directly into medullary cavity of ilium. Results 28 recipients showed hematopoietic reconstitution when PLT was up to 20×109/L and granulocytes was up to 2.0×109/L on day 28 post MSCs infusion. Bone marrow biopsy showed hyperplasia from hypoplasia to evident hyperplasia. On day 28, Th cells ascended from 23.0 to 36.2, Ts cells descended from 24.2 to 14.6, Th.. MTs from 0.95 to 2.47:1, IgG from 6.6 to 13.3, NK cells from 2.40 to 13.5, indicating earlier immune recorrect. At the last follow-up of 12 months, 17 patients showed normal hemoglobin and platelet counts, immune globulin was in the normal level, indicating the hematopoietisis and immune persistent reconstitution. 5 patients still needed infusing constituent blood cells, although, the interval of platelet and red blood cells infusion obviously prolonged, and the times to see doctor decreased and life quality elevated greatly. Conclusion This is a novel clinical research of successful treatment of refractory CAA and MF, it tell us infusion HLA-mismatched allogenic MSCs directly into medullary cavity of ilium is efficiency and security. Disclosures: No relevant conflicts of interest to declare.

Feedback Through Dusp6 Modulates Ineffective Erythropoiesis Caused By Mutant Kras

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 750-750
Author(s):  
Charisa Cottonham ◽  
Roeltje R. Maas ◽  
Benjamin S. Braun
Keyword(s):  
Bone Marrow ◽  
Red Blood Cells ◽  
Negative Feedback ◽  
Peripheral Blood ◽  
Blood Cells ◽  
White Blood Count ◽  
Ras Signaling ◽  
Wild Type ◽  
Hematopoietic Progenitors ◽  
Oncogenic Ras

Abstract Somatic mutations that activate Ras signaling are common in hematologic malignancies. They are particularly associated with juvenile and chronic myelomonocytic leukemias, which are classified as ‘overlap’ myelodysplastic syndromes / myeloproliferative neoplasms (MDS/MPN). These diseases are characterized by myelomonocytic proliferation and dysplasia leading to anemia and thrombocytopenia. We have previously shown that conditional expression of KrasG12D in mice models MDS/MPN, producing a fatal disease with increased granulocyte/macrophage (G/M) progenitors and a reduction in the megakaryocyte/erythroid (Meg/E) lineage. Despite intensive study of Ras signaling, the mechanisms by which oncogenic Ras regulates cell fate decisions in hematopoiesis remain unclear; better understanding of these processes may allow development of novel therapies for MDS/MPN. We found that mRNA and protein levels of dual specificity phosphatase-6 (Dusp6), a negative regulator of MAPK signaling, is elevated in the bone marrow of KrasG12D mice. This suggested that a negative feedback loop generated by Dusp6 might regulate the proliferation and differentiation of hematopoietic progenitors in MDS/MPN. To test this hypothesis, we conditionally expressed KrasG12D from its endogenous locus in the bone marrow of wild type and Dusp6 knockout mice. Interestingly, many characteristics of MDS/MPN were more severe in Dusp6-/-; KrasG12D mice. For example, we observed significantly lower hemoglobin levels in 3-4 week old Dusp6-/-; KrasG12D mice (8.35g/dL, n=4) compared to Dusp6+/+; KrasG12D mice (11.7g/dL, n=10). Moreover, the peripheral blood of Dusp6+/+; KrasG12D mice contained approximately 13% of reticulocytes (n=12), whereas Dusp6-/-; KrasG12D mice had nearly 36% reticulocytes (n=4) in the peripheral blood. Furthermore, we observed acanthocytes, poikilocytes and other structural abnormalities in the red blood cells from Dusp6-/-; KrasG12D mice and not in mice wild type for Dusp6. Thus, Dusp6 loss accelerates the onset of anemia caused by KrasG12D, which suggests an exacerbation of the erythroid differentiation defect. We did not observe any significant differences in white blood count or spleen size attributable to Dusp6 genotype. Differentiation of hematopoietic progenitors was assessed in the bone marrow by flow cytometry. The frequency of pre-Meg/E progenitors (Lin-Sca1-Kit+CD34+FcgR-CD150+CD105-) from Dusp6-/-; KrasG12D mice was reduced by approximately 50% when compared to Dusp6+/+; KrasG12D mice. Consistent with this result, Dusp6-/-; KrasG12D mice possessed a significantly greater percentage of immature red blood cells (proerythroblasts; CD71hi Ter119+) and fewer mature red blood cells (orthochromatic erythroblasts; CD71+ Ter119+) than bone marrow cells from Dusp6+/+; KrasG12D mice. By contrast, Dusp6 expression does not have an effect on the frequency of pre-G/M cells (Lin-Sca1-Kit+CD34+FcgR-CD150-CD105-), which remains unchanged between Dusp6+/+; KrasG12D and Dusp6-/-; KrasG12D mice. Together, these findings demonstrate that negative feedback through Dusp6 functions to maintain erythropoiesis the context of oncogenic Ras signaling. Futher, these data strengthen the association between excessive MAPK activity and dyserythropoiesis, and further support development of inhibitors of MEK and/or ERK to treat MDS/MPN. Disclosures: No relevant conflicts of interest to declare.

scholarly journals EXPERIMENTAL BONE MARROW REACTIONS

1926 ◽  
Vol 43 (4) ◽  
pp. 533-553 ◽  
Author(s):  
Gulli Lindh Muller
Keyword(s):  
Bone Marrow ◽  
Red Blood Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Peripheral Circulation ◽  
Similar Type ◽  
Bone Marrow Aplasia ◽  
Clear Cut ◽  
Initial Stage ◽  
Small Doses

1. The effect produced by the intravenous administration of collargol on the bone marrow of rabbits varies directly with the amount of collargol injected, and three fairly well defined stages could be recognized. (a) An initial stage after comparatively few and small doses, with erythrocytic and endothelial hyperplasia in the bone marrow and with evidences of this stimulation in the peripheral blood in the form of young erythrocytes and normoblasts. (b) An intermediary stage which followed the injection of larger amounts of collargol, and which was characterized by a predominant myeloid hyperplasia. (c) A final stage with marked bone marrow aplasia and with colloidal silver deposited in endothelial cells, as well as in clasmatocytes. This was associated with a high grade anemia with low color index, resembling aplastic anemia in its main features. This stage terminated fatally. 2. There was no evidence of injury to blood cells in the peripheral circulation. The erythrocytic bone marrow aplasia was present before any appreciable decrease of red blood cells was found in the peripheral blood. 3. The results were less clear-cut in a series of rats, but anemia of a similar type was produced in all animals when sufficiently large doses were injected. 4. Splenectomy did not alter the course in rats materially. 5. It is fair to conclude that the cause of the anemia produced may be sought in the deviation of the parental endothelial cell toward clasmatocyte formation at the expense of the development of erythrocytes. 6. It is suggested that the results may be offered in support of the theory of the endothelial origin of both clasmatocytes and red blood cells.

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