scholarly journals Polycythemia

2020 ◽  
pp. 38-43
Author(s):  
Stanley Kim ◽  
Ricardo Saca ◽  
Pamela Harford
Keyword(s):  
Stem Cell ◽  
Polycythemia Vera ◽  
Myeloproliferative Neoplasm ◽  
Hematocrit Level ◽  
Cell Disease ◽  
Erythroid Progenitors ◽  
Cell Numbers ◽  
Erythropoietin Level ◽  
Secondary Polycythemia ◽  
Rbc Count

Polycythemia is a disease state in which the red blood cell numbers are increased in the blood (erythrocytosis), which in turn makes blood thicker and can cause circulatory problems. Polycythemia Vera is a stem cell disease belonged to a group of myeloproliferative neoplasm in which the erythroid progenitors are overly proliferated by acquired mutation of the JAK2 gene, resulting in excessive erythrocytosis. Secondary Polycythemia refers erythrocytosis due to underlying conditions. It is usually associated with increased blood erythropoietin levels as a compensatory reaction to tissue hypoxia, which can be seen in patients with chronic lung disease or sleep apnea or living at high altitudes. Certain tumors produce the erythropoiet ©Win and testosterestern University of Heone incralth Scienceseases the blood erythropoietin level, resulting in secondary polycythemia. Relative polycythemia is the consequence of plasma volume contraction, falsely raising the RBC count and hemoglobin/hematocrit level in CBC. Two cases of polycythemia are presented: 1) a patient with polycythemia vera and 2) a patient with secondary polycythemia. Various types of polycythemia are discussed with an updated review covering the etiology, clinical manifestation, diagnostic approach and treatment.

Growth and Differentiation of Human Stem Cell Factor/Erythropoietin-Dependent Erythroid Progenitor Cells In Vitro

Blood ◽  
1998 ◽  
Vol 92 (10) ◽  
pp. 3658-3668 ◽  
Author(s):  
Birgit Panzenböck ◽  
Petr Bartunek ◽  
Markus Y. Mapara ◽  
Martin Zenke
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Large Cell ◽  
Erythroid Cell ◽  
Erythroid Progenitors ◽  
Peripheral Blood Stem Cells ◽  
Erythroid Progenitor ◽  
Cell Numbers

Abstract Stem cell factor (SCF) and erythropoietin (Epo) effectively support erythroid cell development in vivo and in vitro. We have studied here an SCF/Epo-dependent erythroid progenitor cell from cord blood that can be efficiently amplified in liquid culture to large cell numbers in the presence of SCF, Epo, insulin-like growth factor-1 (IGF-1), dexamethasone, and estrogen. Additionally, by changing the culture conditions and by administration of Epo plus insulin, such progenitor cells effectively undergo terminal differentiation in culture and thereby faithfully recapitulate erythroid cell differentiation in vitro. This SCF/Epo-dependent erythroid progenitor is also present in CD34+ peripheral blood stem cells and human bone marrow and can be isolated, amplified, and differentiated in vitro under the same conditions. Thus, highly homogenous populations of SCF/Epo-dependent erythroid progenitors can be obtained in large cell numbers that are most suitable for further biochemical and molecular studies. We demonstrate that such cells express the recently identified adapter protein p62dok that is involved in signaling downstream of the c-kit/SCF receptor. Additionally, cells express the cyclin-dependent kinase (CDK) inhibitors p21cip1 and p27kip1 that are highly induced when cells differentiate. Thus, the in vitro system described allows the study of molecules and signaling pathways involved in proliferation or differentiation of human erythroid cells.

Growth and Differentiation of Human Stem Cell Factor/Erythropoietin-Dependent Erythroid Progenitor Cells In Vitro

Blood ◽  
1998 ◽  
Vol 92 (10) ◽  
pp. 3658-3668 ◽  
Author(s):  
Birgit Panzenböck ◽  
Petr Bartunek ◽  
Markus Y. Mapara ◽  
Martin Zenke
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Large Cell ◽  
Erythroid Cell ◽  
Erythroid Progenitors ◽  
Peripheral Blood Stem Cells ◽  
Erythroid Progenitor ◽  
Cell Numbers

Stem cell factor (SCF) and erythropoietin (Epo) effectively support erythroid cell development in vivo and in vitro. We have studied here an SCF/Epo-dependent erythroid progenitor cell from cord blood that can be efficiently amplified in liquid culture to large cell numbers in the presence of SCF, Epo, insulin-like growth factor-1 (IGF-1), dexamethasone, and estrogen. Additionally, by changing the culture conditions and by administration of Epo plus insulin, such progenitor cells effectively undergo terminal differentiation in culture and thereby faithfully recapitulate erythroid cell differentiation in vitro. This SCF/Epo-dependent erythroid progenitor is also present in CD34+ peripheral blood stem cells and human bone marrow and can be isolated, amplified, and differentiated in vitro under the same conditions. Thus, highly homogenous populations of SCF/Epo-dependent erythroid progenitors can be obtained in large cell numbers that are most suitable for further biochemical and molecular studies. We demonstrate that such cells express the recently identified adapter protein p62dok that is involved in signaling downstream of the c-kit/SCF receptor. Additionally, cells express the cyclin-dependent kinase (CDK) inhibitors p21cip1 and p27kip1 that are highly induced when cells differentiate. Thus, the in vitro system described allows the study of molecules and signaling pathways involved in proliferation or differentiation of human erythroid cells.

Clonal hematopoiesis in familial polycythemia vera suggests the involvement of multiple mutational events in the early pathogenesis of the disease

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3793-3796 ◽  
Author(s):  
Robert Kralovics ◽  
David W. Stockton ◽  
Josef T. Prchal
Keyword(s):  
Stem Cell ◽  
Polycythemia Vera ◽  
Cell Clone ◽  
Incomplete Penetrance ◽  
Erythroid Progenitors ◽  
Familial Predisposition ◽  
Clonal Hematopoiesis ◽  
Healthy Family ◽  
Cell Defect ◽  
Autosomal Dominant Inheritance Pattern

AbstractFamilial clustering of malignancies provides a unique opportunity to identify molecular causes of cancer. Polycythemia vera (PV) is a myeloproliferative disorder due to an unknown somatic stem cell defect that leads to clonal myeloid hyperproliferation. We studied 6 families with PV. The familial predisposition to PV appears to follow an autosomal dominant inheritance pattern with incomplete penetrance. All examined females informative for a transcriptional clonality assay had clonal hematopoiesis. We excluded linkage between PV and a number of previously proposed candidate disease loci (c-mpl, EPOR, 20q, 13q, 5q, 9p). Therefore, mutations at these loci are unlikely primary causes of familial PV. The finding of erythropoietin-independent erythroid progenitors in healthy family members indicated the presence of the PV stem cell clone in their hematopoiesis. This finding, together with clonal hematopoiesis in the affected individuals, supports the hypothesis of multiple genetic defects involved in the early pathogenesis of PV. (Blood. 2003;102:3793-3796)

scholarly journals Btk Is Required for an Efficient Response to Erythropoietin and for SCF-controlled Protection against TRAIL in Erythroid Progenitors

2004 ◽  
Vol 199 (6) ◽  
pp. 785-795 ◽  
Author(s):  
Uwe Schmidt ◽  
Emile van den Akker ◽  
Martine Parren-van Amelsvoort ◽  
Gabi Litos ◽  
Marella de Bruijn ◽  
...  
Keyword(s):  
Stem Cell ◽  
Signaling Pathways ◽  
Peripheral Blood ◽  
Stem Cell Factor ◽  
Trail Receptor ◽  
Erythroid Progenitors ◽  
Cell Numbers ◽  
Downstream Signaling ◽  
Increased Sensitivity ◽  
Induced Apoptosis

Regulation of survival, expansion, and differentiation of erythroid progenitors requires the well-controlled activity of signaling pathways induced by erythropoietin (Epo) and stem cell factor (SCF). In addition to qualitative regulation of signaling pathways, quantitative control may be essential to control appropriate cell numbers in peripheral blood. We demonstrate that Bruton's tyrosine kinase (Btk) is able to associate with the Epo receptor (EpoR) and Jak2, and is a substrate of Jak2. Deficiency of Btk results in reduced and delayed phosphorylation of the EpoR, Jak2, and downstream signaling molecules such as Stat5 and PLCγ1 as well as in decreased responsiveness to Epo. As a result, expansion of erythroid progenitors lacking Btk is impaired at limiting concentrations of Epo and SCF. In addition, we show that SCF induces Btk to interact with TNF-related apoptosis-inducing ligand (TRAIL)–receptor 1 and that lack of Btk results in increased sensitivity to TRAIL-induced apoptosis. Together, our results indicate that Btk is a novel, quantitative regulator of Epo/SCF-dependent expansion and survival in erythropoiesis.

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