The binding of late stage erythroid cells to fibronectin (FN) has been well characterized and is believed to be critical for the terminal stages of erythroid differentiation, but the adhesive properties of more primitive murine erythroid progenitors and the role of these interactions during earlier stages of erythropoiesis has not been determined. Using chymotryptic fragments and inhibitory pro...

Colony assays are now available to study erythroid differentiation at three different levels. Mixed hemopoietic colonies represent progeny of pluripotent progenitors (CFU-GEMM). Erythroid bursts and cobnies are derived from early (BFU-E) and late precursors (CFU-E) that are committed towards erythropoiesis. The three different types of colonies were examined for their content of fetal hemoglobi...

The sedimentation velocity profiles of the entities in mouse bone marrow responsible for erythropoietic burst formation (BFU-E) and for erythrocytic colony formation (CFU-E) have been studied under conditions designed to determine whether the values observed are real or result from cell interactions occurring during culture of the fractions. Bone marrow cells of adult C3Hf/Bi mice were subjecte...

The proliferative state of human pluripotent hemopoietic progenitors (CFU-GEMM) was assessed in normal bone marrow transplant donors and in recipients after engraftment using the tritiated thymidine suicide method. In contrast to BFU-E and CFU-C, CFU-GEMM were found to be quiescent. In samples obtained during early regeneration after transplantation, CFU-GEMM were significantly reduced after sh...

To facilitate the direct study of progenitor cell biology, we have developed a simple and efficient procedure based upon negative selection by panning to purify large numbers of committed erythroid and myeloid progenitors from human fetal liver. The nonadherent, panned cells constitute a highly enriched population of progenitor cells, containing 30.4 +/- 13.1% erythrocyte burst forming units (B...

Bone marrow cells from ten normal donors were exposed to ultraviolet (UV)C or UVB light for total exposures of 0.1 to 100 mJ/cm2, and assayed for granulocyte-macrophage colony-forming units (CFU-GM), erythroid burst-forming units (BFU-E), and phytohemagglutinin (PHA)-stimulated proliferative responses. After exposure to UVC CFU-GM, BFU-E and PHA responses showed a UV dose-dependent sharp decrea...

Transcription factor GATA-1 is essential for the development of the erythroid lineage. To ascertain whether strict control of GATA-1 expression level is necessary for achieving proper erythropoiesis, we established transgenic mouse lines expressing green fluorescent protein (GFP) under the control of the GATA-1 gene hematopoietic regulatory domain. We examined the GATA-1 expression level by exp...

Twelve cases of transient erythroblastopenia of childhood (TEC) have been studied to evaluate their marrow cell erythropoiesis in vitro and the effect on it of their serum or IgG. The number of colony-forming units-erythroid (CFU-E) and burst-forming units-erythroid (BFU-E) in the bone marrow of nine cases was extremely variable and did not allow any conclusion regarding the pathogenesis of thi...

Erythropoietin (EPO) is the hormone necessary for development of erythrocytes from immature erythroid cells. EPO activates Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase (MAPK) family in the EPO-dependent murine erythroid HCD57 cells. Therefore, we tested if JNK activity supported proliferation and/or survival of these cells. Treatment with the JNK inhibitor SP600...

Anemia has been associated with aluminum intoxication in patients on chronic dialysis and in animals. In studies presented here, in vitro human erythroid culture was used to delineate the effects of aluminum on normal hematopoiesis. Aluminum by itself in routine culture, even at very high levels (1,035 ng/ml), did not significantly affect erythroid colony growth. The addition of human transferr...