scholarly journals Runx1 is sufficient for blood cell formation from non-hemogenic endothelial cells in vivo only during early embryogenesis

Development ◽  
2018 ◽  
Vol 145 (2) ◽  
pp. dev158162 ◽  
Author(s):  
Amanda D. Yzaguirre ◽  
Elizabeth D. Howell ◽  
Yan Li ◽  
Zijing Liu ◽  
Nancy A. Speck
Keyword(s):  
Endothelial Cells ◽  
Blood Cell ◽  
Cell Formation ◽  
Early Embryogenesis ◽  
Blood Cell Formation

scholarly journals Multi-Agent Systems and Blood Cell Formation

10.5772/15950 ◽  
2011 ◽  
Author(s):  
Bessonov Nikolai ◽  
Demin Ivan ◽  
Kurbatova Polina ◽  
Pujo-Menjouet Laurent ◽  
Volpert Vitaly
Keyword(s):  
Blood Cell ◽  
Cell Formation ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Multi Agent ◽  
Blood Cell Formation

Expression of connexin 43 (Cx43) is critical for normal hematopoiesis

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Encarnacion Montecino-Rodriguez ◽  
Hyosuk Leathers ◽  
Kenneth Dorshkind
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Blood Cell ◽  
Gap Junctions ◽  
Connexin 43 ◽  
Cell Formation ◽  
Cx43 Expression ◽  
Hematopoietic System ◽  
Blood Cell Formation

Abstract Gap junctions are intercellular channels, formed by individual structural units known as connexins (Cx), that allow the intercellular exchange of various messenger molecules. The finding that numbers of Cx43-type gap junctions in bone marrow are elevated during establishment and regeneration of the hematopoietic system has led to the hypothesis that expression of Cx43 is critical during the initiation of blood cell formation. To test this hypothesis, lymphoid and myeloid development were examined in mice with a targeted disruption of the gene encoding Cx43. Because Cx43−/− mice die perinatally, initial analyses were performed on Cx43−/−, Cx43+/−, and Cx43+/+ embryos and newborns. The data indicate that lack of Cx43 expression during embryogenesis compromises the terminal stages of primary T and B lymphopoiesis. Cx43−/− embryos and neonates had a reduced frequency of CD4+ and T-cell receptor-expressing thymocytes and surface IgM+cells compared to their Cx43+/+ littermates. Surprisingly, Cx43+/− embryos/neonates also showed defects in B- and T-cell development similar to those observed in Cx43−/− littermates, but their hematopoietic system was normal at 4 weeks of age. However, the regeneration of lymphoid and myeloid cells was severely impaired in the Cx43+/− mice after cytoablative treatment. Taken together, these data indicate that loss of a single Cx43 allele can affect blood cell formation. Finally, the results of reciprocal bone marrow transplants between Cx43+/+ and Cx43+/− mice and examination of hematopoietic progenitors and stromal cells in vitro indicates that the primary effects of Cx43 are mediated through its expression in the hematopoietic microenvironment.

Blood Cell Formation in Certain Teleost Fishes

Blood ◽  
1951 ◽  
Vol 6 (1) ◽  
pp. 39-60 ◽  
Author(s):  
W. T. CATTON
Keyword(s):  
Blood Cell ◽  
Blood Cells ◽  
Cell Formation ◽  
Large Cell ◽  
Progressive Increase ◽  
Mitotic Division ◽  
Teleost Fishes ◽  
Epithelial Surface ◽  
Alternative Hypotheses ◽  
Blood Cell Formation

Abstract 1. The blood cells of trout and roach consist of nucleated erythrocytes and reticulocytes, nucleated thrombocytes, coarse and fine granulocytes, and lymphocytes of varying sizes. It is difficult to distinguish any cells showing characteristics similar to those of the monocytes of mammals. Immature cells occur more frequently in the blood than is the case in mammals. 2. The coarse granulocytes very commonly escape from the blood vessels, and have been observed in large numbers in the intestinal mucosa and submucosa, in the gill epithelia, and in the peritoneum. These cells migrate to the epithelial surface, where they undergo changes in structure leading to the formation of a characteristic discharge pattern of their granules. It is proposed that the "granules" are in reality vesicles with fluid contents, which are ultimately discharged at epithelial surfaces. 3. The hematopoietic organs of these fishes are chiefly the intertubular tissues of the kidneys; in the trout the spleen is also active; in the roach, only the kidney is active; in the perch, only the spleen is active. 4. Two alternative hypotheses of blood cell formation are proposed. On the first hypothesis, the common stem cell is described as a "large lymphoid hemoblast," which gives rise to granulocytes by direct transformation and undergoes mitotic division to give rise to "small lymphoid hemoblasts." From the latter develop the erythrocytes, thrombocytes and blood lymphocytes. On the second hypothesis, the large lymphoid hemoblast, derived by transformation of reticular cells is the precursor solely of the granulocytes, and the small lymphoid hemoblast is to be derived from endothelial cells and is the precursor of erythrocytes and thrombocytes. In this case the large cell is to be compared with the "primitive white cell" of Doan, Cunningham and Sabin, and the small cell with the "megaloblast" of the same authors. No evidence however is available of the derivation of small hemoblasts from endothelial cell components of the reticulo-endothelium. 5. In the maturation of the erythrocyte in teleost fishes, there is a progressive increase in the size of the cell; in mammals and birds there is a decrease in size. In both cases there is a decrease in size in granulocyte maturation. 6. There are no essential differences between the blood cells and hematopoietic processes of the freshwater and marine teleost fishes examined.

Additive effect of red blood cell rigidity and adherence to endothelial cells in inducing vascular resistance

2008 ◽  
Vol 295 (4) ◽  
pp. H1788-H1793 ◽  
Author(s):  
D. K. Kaul ◽  
A. Koshkaryev ◽  
G. Artmann ◽  
G. Barshtein ◽  
S. Yedgar
Keyword(s):  
Endothelial Cells ◽  
Blood Cell ◽  
Vascular Resistance ◽  
Red Blood Cell ◽  
Untreated Control ◽  
Additional Increase ◽  
Specific Effects ◽  
Induced Changes ◽  
Rbc Deformability

To explore the contribution of red blood cell (RBC) deformability and interaction with endothelial cells (ECs) to circulatory disorders, these RBC properties were modified by treatment with hydrogen peroxide (H2O2), and their effects on vascular resistance were monitored following their infusion into rat mesocecum vasculature. Treatment with 0.5 mM H2O2 increased RBC/EC adherence without significant alteration of RBC deformability. At 5.0 mM H2O2, RBC deformability was considerably reduced, inducing a threefold increase in the number of undeformable cells, whereas RBC/EC adherence was not further affected by the increased H2O2 concentration. This enabled the selective manipulation of RBC adherence and deformability and the testing of their differential effect on vascular resistance. Perfusion of RBCs with enhanced adherence and unchanged deformability (treatment with 0.5 mM H2O2) increased vascular resistance by about 35% compared with untreated control RBCs. Perfusion of 5.0 mM H2O2-treated RBCs, with reduced deformability (without additional increase of adherence), further increased vascular resistance by about 60% compared with untreated control RBCs. These results demonstrate the specific effects of elevated adherence and reduced deformability of oxidized RBCs on vascular resistance. These effects can be additive, depending on the oxidation conditions. The oxidation-induced changes applied in this study are moderate compared with those observed in RBCs in pathological states. Yet, they caused a considerable increase in vascular resistance, thus demonstrating the potency of RBC/EC adherence and RBC deformability in determining resistance to blood flow in vivo.

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