Zidovudine (AZT) treatment suppresses granulocyte-monocyte colony stimulating factor receptor type alpha (GM-CSFRα) gene expression in murine bone marrow cells

Life Sciences ◽  
2002 ◽  
Vol 71 (8) ◽  
pp. 967-978 ◽  
Author(s):  
Shilpa Chitnis ◽  
Debasis Mondal ◽  
Krishna C Agrawal
Blood ◽  
1982 ◽  
Vol 59 (2) ◽  
pp. 408-420 ◽  
Author(s):  
G Pigoli ◽  
A Waheed ◽  
RK Shadduck

Abstract Radioiodinated L-cell-derived colony-stimulating factor (CSF) was used to characterize the binding reaction to murine bone marrow cells. The major increment in cell-associated radioactivity occurred over 24 hr incubation at 37 degrees C, but virtually no binding was observed at 4 degrees C. The reaction was saturable with approximately 1 ng/ml of purified CSF. Unlabeled CSF prevented the binding, whereas a number of other hormones and proteins did not compete for CSF uptake. Further specificity studies showed virtually no binding to human bone marrow, which is unresponsive to this form of murine CSF. Minimal CSF uptake was noted with murine peritoneal macrophages, but virtually no binding was detected with thymic, lymph node, liver, or kidney cells. The marrow cell interaction with tracer appeared to require a new protein synthesis, as the binding was prevented by cycloheximide or puromycin. Preincubation of marrow cells in medium devoid of CSF increased the degree of binding after 1 hr exposure to the tracer. This suggests that CSF binding sites may be occupied or perhaps decreased in response to ambient levels of CSF in vivo. Approximately 70% of the bound radioactivity was detected in the cytoplasm at 24 hr. This material was partially degraded as judged by a decrease in molecular weight from approximately 62,000 to 2 peaks of approximately 32,000 and approximately 49,000, but 72% of the binding activity was retained. After plateau binding was achieved, greater than 80% of the radioactivity released into the medium was degraded into biologically inactive peptides with molecular weights less than 10,000. These findings suggest that the interaction of CSF with marrow cells is characterized by binding with subsequent internalization and metabolic degradation into portions of the molecule that are devoid of biologic activity.


Blood ◽  
1983 ◽  
Vol 62 (6) ◽  
pp. 1197-1202
Author(s):  
RK Shadduck ◽  
G Pigoli ◽  
C Caramatti ◽  
G Degliantoni ◽  
V Rizzoli ◽  
...  

Binding of radiolabeled L-cell colony-stimulating factor (CSF) was studied using murine bone marrow and fetal liver cells. With 10(7) cells, saturation of binding was seen with approximately 500,000 cpm of 125I-CSF. Minimal binding was detected after one hour incubation with tracer at 37 degrees C; however, marked cellular uptake of radioactivity was noted after 24-hr exposure to CSF. As judged by autoradiographs, small numbers of myeloblasts, promyelocytes, and large mononuclear cells were labeled with 1-hr exposure to tracer. By 6 hr of incubation, 50%-70% of myeloblasts and promyelocytes and small numbers of late granulocytic cells were labeled. Virtually all myeloblasts and promyelocytes and approximately 50% of myelocytes, metamyelocytes, polymorphonuclear granulocytes, and monocytes were labeled after 24-hr exposure to the radioiodinated CSF. Label was not detected on erythroblasts, eosinophils, or megakaryocytes. Suspensions of fetal liver cells had lower uptake of radioactivity than bone marrow cells. This appeared to result from a lesser concentration of granulocytic cells in fetal liver, as labeling of individual cells was similar with both tissues. In additional experiments, CSF binding to marrow cells was assessed after 30-min exposure to tracer at 0 degrees C. Uptake of 125I-CSF exceeded that observed after 24-hr incubation at 37 degrees C. With this technique, cellular label was also confined to granulocytic and monocytic cells. These findings suggest that purified CSF reacts with and may stimulate immature and mature cells of the granulocytic and monocytic lineages.


Blood ◽  
1982 ◽  
Vol 59 (2) ◽  
pp. 408-420
Author(s):  
G Pigoli ◽  
A Waheed ◽  
RK Shadduck

Radioiodinated L-cell-derived colony-stimulating factor (CSF) was used to characterize the binding reaction to murine bone marrow cells. The major increment in cell-associated radioactivity occurred over 24 hr incubation at 37 degrees C, but virtually no binding was observed at 4 degrees C. The reaction was saturable with approximately 1 ng/ml of purified CSF. Unlabeled CSF prevented the binding, whereas a number of other hormones and proteins did not compete for CSF uptake. Further specificity studies showed virtually no binding to human bone marrow, which is unresponsive to this form of murine CSF. Minimal CSF uptake was noted with murine peritoneal macrophages, but virtually no binding was detected with thymic, lymph node, liver, or kidney cells. The marrow cell interaction with tracer appeared to require a new protein synthesis, as the binding was prevented by cycloheximide or puromycin. Preincubation of marrow cells in medium devoid of CSF increased the degree of binding after 1 hr exposure to the tracer. This suggests that CSF binding sites may be occupied or perhaps decreased in response to ambient levels of CSF in vivo. Approximately 70% of the bound radioactivity was detected in the cytoplasm at 24 hr. This material was partially degraded as judged by a decrease in molecular weight from approximately 62,000 to 2 peaks of approximately 32,000 and approximately 49,000, but 72% of the binding activity was retained. After plateau binding was achieved, greater than 80% of the radioactivity released into the medium was degraded into biologically inactive peptides with molecular weights less than 10,000. These findings suggest that the interaction of CSF with marrow cells is characterized by binding with subsequent internalization and metabolic degradation into portions of the molecule that are devoid of biologic activity.


Blood ◽  
1983 ◽  
Vol 62 (6) ◽  
pp. 1197-1202 ◽  
Author(s):  
RK Shadduck ◽  
G Pigoli ◽  
C Caramatti ◽  
G Degliantoni ◽  
V Rizzoli ◽  
...  

Abstract Binding of radiolabeled L-cell colony-stimulating factor (CSF) was studied using murine bone marrow and fetal liver cells. With 10(7) cells, saturation of binding was seen with approximately 500,000 cpm of 125I-CSF. Minimal binding was detected after one hour incubation with tracer at 37 degrees C; however, marked cellular uptake of radioactivity was noted after 24-hr exposure to CSF. As judged by autoradiographs, small numbers of myeloblasts, promyelocytes, and large mononuclear cells were labeled with 1-hr exposure to tracer. By 6 hr of incubation, 50%-70% of myeloblasts and promyelocytes and small numbers of late granulocytic cells were labeled. Virtually all myeloblasts and promyelocytes and approximately 50% of myelocytes, metamyelocytes, polymorphonuclear granulocytes, and monocytes were labeled after 24-hr exposure to the radioiodinated CSF. Label was not detected on erythroblasts, eosinophils, or megakaryocytes. Suspensions of fetal liver cells had lower uptake of radioactivity than bone marrow cells. This appeared to result from a lesser concentration of granulocytic cells in fetal liver, as labeling of individual cells was similar with both tissues. In additional experiments, CSF binding to marrow cells was assessed after 30-min exposure to tracer at 0 degrees C. Uptake of 125I-CSF exceeded that observed after 24-hr incubation at 37 degrees C. With this technique, cellular label was also confined to granulocytic and monocytic cells. These findings suggest that purified CSF reacts with and may stimulate immature and mature cells of the granulocytic and monocytic lineages.


Blood ◽  
1990 ◽  
Vol 75 (12) ◽  
pp. 2286-2291 ◽  
Author(s):  
K Koike ◽  
T Nakahata ◽  
T Kubo ◽  
T Kikuchi ◽  
M Takagi ◽  
...  

We investigated the effect of interleukin-6 (IL-6) on murine megakaryocytopoiesis in a serum-free culture system. The addition of IL- 6 to a culture containing interleukin-3 (IL-3) resulted in a significant increase in the number of megakaryocyte colonies by bone marrow cells of normal mice. The megakaryocytic progenitors that survive exposure to 5-fluorouracil (5-FU) exhibited a more significant response to IL-6 and IL-3. Polyclonal anti-IL-6 antibody neutralized the stimulatory effect of IL-6 on megakaryocyte colony growth supported by IL-3. Delayed addition experiments and replating experiments of blast cell colonies showed that megakaryocytic progenitors are supported by IL-3 in the early stage of the development but require IL- 6 for their subsequent proliferation and differentiation. In addition, IL-6 increased the size of megakaryocytes in granulocyte-macrophage- megakaryocyte colonies. The combination of granulocyte colony- stimulating factor or granulocyte-macrophage colony stimulating factor with IL-3 resulted in an increase in the granulocyte-macrophage colony growth of bone marrow cells of 5-FU-treated mice or normal mice, respectively, but had little effect on the enhancement of pure and mixed megakaryocyte colony growth. These results suggest that IL-6 plays an important role in murine megakaryocytopoiesis.


Blood ◽  
1997 ◽  
Vol 89 (4) ◽  
pp. 1165-1172 ◽  
Author(s):  
Russell S. Taichman ◽  
Marcelle J. Reilly ◽  
Rama S. Verma ◽  
Stephen G. Emerson

Abstract Based on anatomic and developmental findings characterizing hematopoietic cells in close approximation with endosteal cells, we have begun an analysis of osteoblast/hematopoietic cell interactions. We explore here the functional interdependence between these two cell types from the standpoint of de novo cytokine secretion. We determined that, over a 96-hour period, CD34+ bone marrow cells had no significant effect on osteoblast secretion of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or transforming growth factor-β1 , but in some experiments minor increases in leukemia inhibitory factor levels were observed. However, when CD34+ bone marrow cells were cocultured in direct contact with osteoblasts, a 222% ± 55% (range, 153% to 288%) augmentation in interleukin-6 (IL-6) synthesis was observed. The accumulation of IL-6 protein was most rapid during the initial 24-hour period, accounting for nearly 55% of the total IL-6 produced by osteoblasts in the absence of blood cells and 77% of the total in the presence of the CD34+ cells. Cell-to-cell contact does not appear to be required for this activity, as determined by coculturing the two cell types separated by porous micromembranes. The identity of the soluble activity produced by the CD34+ cells remains unknown, but is not likely due to IL-1β or tumor necrosis factor-α, as determined with neutralizing antibodies. To our knowledge, these data represent the first demonstration that early hematopoietic cells induce the production of molecules required for the function of normal bone marrow microenvironments, in this case through the induction of hematopoietic cytokine (IL-6) secretion by osteoblasts.


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