Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied myelodysplastic syndrome-associated inhibitory activity (MDS-IA), which inhibited colony formation in vitro of normal granulocyte-macrophage progenitors (CFU-GM). When adherent marrow cells were incubated with fetal calf serum for 21-24 d, monocyte-derived lipid containing huge macrophages (MDLM) developed. MDLM from MDS marrow (MDS-MDLMs) and their conditioned medium (MDLM-CM) consistently suppressed the growth of normal CFU-GM colony formation. MDS-IA was active on CFU-GM during the S-phase and relatively resistant to heating. Monoclonal antibody against H subunit (acidic) ferritin and polyclonal antibody against placental ferritin neutralized the inhibitory activity of MDS-MDLMs. In addition, cell lysates of MDS-MDLMs reacted to both monoclonal anti-H subunit ferritin and polyclonal anti-placental ferritin in Western blotting analysis, indicating that the inhibitory activity was predominantly acidic isoferritin. On the other hand, MDLMs obtained from normal bone marrow had a CFU-GM enhancing activity. These results suggest that MDS-MDLMs may be responsible for the suppression of granulopoiesis in patients with MDS and that the suppression may be mediated by soluble factors, notably H subunit isoferritin.
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PMID:Myelodysplastic syndrome (MDS)-associated inhibitory activity on haematopoietic progenitor cells: contribution of monocyte-derived lipid containing macrophages (MDLM). 152 Jun 27

We studied MDS-associated inhibitory activity, which inhibited colony formation in vitro of granulocyte-macrophage progenitors (CFU-GM). Macrophages obtained from MDS bone marrow mononuclear cells (BM-MNC) when pretreated with granulocyte-macrophage colony stimulating factor (GM-CSF) suppressed the growth of normal CFU-GM. These macrophages were designated as 'MDS-derived inhibitory macrophages'. Media conditioned by MDS-derived inhibitory macrophages (MDS-CM) also suppressed the growth of normal CFU-GM. In the MDS-CM, high levels of prostaglandin E2 (PGE2) and ferritin were found. However, MDS-CM did not contain detectable levels of tumour necrosis factor (TNF) or gamma-interferon (gamma-IFN). Antiserum against human placental ferritin and/or against PGE2 blocked the haemopoietic inhibitory activity to some extent. These results suggest that inhibitory macrophages may be responsible for the suppression of granulopoiesis in patients with MDS and that the suppression may be mediated by soluble factors including PGE2 and ferritin.
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PMID:Myelodysplastic syndrome (MDS)-associated inhibitory activity on haemopoietic progenitor cells. 218 Apr 70

In order to clarify possible factors responsible for varying responses in uremic patients treated with recombinant human erythropoietin (rHuEPO), we determined the inhibitory effects of ten uremic sera on the erythroid progenitors (CFU-E) and erythroid bursts (BFU-E). We also measured plasma EPO titers, Fe, UIBC, ferritin, PTH-C, beta 2-microglobulin, and aluminum in all ten patients. The inhibitor of CFU-E but not BFU-E, was present in the serum of the single anemic patient whose recovery took longer after the administration of rHuEPO. He did not have such conditions as iron deficiency, excess of aluminum, or chronic inflammation. The remaining patients, who had no CFU-E or BFU-E inhibitors, were good responders to rHuEPO. In none of ten patients were there inhibitors of granulocyte-macrophage progenitors (CFU-GM) or any differences in the other parameters. Although the inhibitory factor of CFU-E can be overcome with a larger dose, its prior determination may be useful to set out minimal effective dose of EPO treatment.
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PMID:The inhibitory factors of hematopoiesis in chronic hemodialysis patients treated with recombinant human erythropoietin. 224 92

Highly purified murine granulocyte-macrophage progenitor cells (CFU-GM) were used as target cells to assess the possible direct effects of purified preparations of recombinant murine gamma-interferon, prostaglandin E, recombinant human heavy chain (acidic) ferritin, and recombinant human tumor necrosis factor alpha (TNF-alpha) on progenitor cells in vitro. Target CFU-GM, with cloning efficiencies of up to 84% and containing 0-3% morphologically recognizable accessory cells at the initiation of the culture period, were plated at a density of 100-150 cells/dish in the presence or absence of pure suppressor molecules. Colony formation was stimulated with either crude pokeweed mitogen-stimulated mouse spleen conditioned medium, pure natural murine macrophage colony-stimulating factor, or pure recombinant murine granulocyte-macrophage colony-stimulating factor. All four suppressor molecules were active in vitro against purified CFU-GM as assessed by their ability to inhibit colony or cluster formation. No apparent difference in the degree of responsiveness to prostaglandin E, gamma-interferon, or human heavy chain (acidic) ferritin was noted in the presence of pokeweed mitogen-stimulated mouse spleen conditioned medium, granulocyte-macrophage colony-stimulating factor, or macrophage colony-stimulating factor. In contrast, TNF-alpha in cultures containing macrophage colony-stimulating factor slightly, but significantly, potentiated colony formation. TNF-alpha also appeared more active at suppressing colony formation at lower concentrations in pokeweed mitogen-stimulated mouse spleen conditioned medium than in granulocyte-macrophage colony-stimulating factor-stimulated cultures of purified CFU-GM. The results suggest that TNF-alpha, human heavy chain (acidic) ferritin, gamma-interferon, and prostaglandin E can act directly at the progenitor cell level.
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PMID:Effects of hematopoietic suppressor molecules on the in vitro proliferation of purified murine granulocyte-macrophage progenitor cells. 244 53

Purified recombinant human heavy-chain (acidic) ferritin (rHF) was assessed in vivo in mice for effects on the proliferation (percentage of cells in S-phase) and absolute numbers of granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells in the femur and spleen and on the nucleated cells in the marrow, spleen, and blood. rHF significantly decreased cycling rates and absolute numbers of marrow and splenic hematopoietic progenitors and marrow and blood nucleated cellularity. These effects were apparent in BDF1, C3H/Hej and DBA/2 mice and were dose dependent, time related, and reversible. Suppressive effects were noted within three hours for progenitor cell cycling, within 24 hours for progenitor cell numbers, and within 48 hours for circulating neutrophils. Additionally, hematopoietic progenitor cells in DBA/2 mice infected with the polycythemia-inducing strain of the Friend virus complex (FVC-P) were insensitive to the in vivo administration of rHF. These studies demonstrate activity of rHF in vivo on myelopoiesis of normal but not FVC-P-infected mice. Since rHF suppresses hematopoietic progenitor cell proliferation from normal donors in vitro and from normal mice in vitro and in vivo but does not suppress progenitor cells from patients with leukemia in vitro or from mice with FVC-P-infection in vitro or in vivo, rHF may be useful as a candidate adjunct molecule for the protection of normal hematopoietic progenitor cells during chemotherapy.
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PMID:Suppressive effects in vivo of purified recombinant human H-subunit (acidic) ferritin on murine myelopoiesis. 291 Mar 70

Bone marrow cells from patients with leukemia, myelodysplastic syndromes, cancer, and other disorders on a phase I clinical trial with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were assessed in vitro for numbers of granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells, and for growth patterns (colony-to-cluster ratio) of CFU-GM, cycling rates of CFU-GM, and responsiveness in vitro to colony-stimulating and colony-inhibiting factors. The colony-to-cluster ratio of CFU-GM and the dose-response curves of CFU-GM to stimulation by rhGM-CSF in vitro did not change during the clinical trial. However, the percentage of CFU-GM in DNA synthesis, which is a measure of the proliferative rates of these cells, determined by the high specific activity tritiated thymidine kill technique in vitro, was markedly enhanced in a reversible fashion after administration in vivo of rhGM-CSF. The increased cycling rates of CFU-GM were consistent with the induced increase in neutrophil counts in these patients that has been reported elsewhere. Additionally, marrow CFU-GM from patients given rhGM-CSF in vivo were increased in sensitivity to inhibition in vitro by recombinant human H-subunit (acidic) ferritin in two of eight cases, and were increased in sensitivity to inhibition by lower dosages of recombinant human tumor necrosis factor alpha in all patients evaluated. The sensitivity of CFU-GM to inhibition in vitro by recombinant human interferon gamma and prostaglandin E1 did not change during the clinical trial. These studies demonstrate that the rhGM-CSF is having an effect on CFU-GM in the patients on the phase I clinical trial. This information may be of significance in planning future clinical studies combining rhGM-CSF with chemotherapy and/or other biotherapy.
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PMID:Growth characteristics of marrow hematopoietic progenitor/precursor cells from patients on a phase I clinical trial with purified recombinant human granulocyte-macrophage colony-stimulating factor. 326 May 58

Purified recombinant human heavy subunit (rHF, acidic) and recombinant human light subunit (rLF, basic) ferritins were assessed for their effects in vitro on colony formation by normal human granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) progenitor cells. The purity of the samples was confirmed by electrophoresis in both nondenaturing and denaturing conditions and silver staining. Concentrations of 10(-8) to 10(-10) mol/L rHF caused an approximately 40% significant decrease in colony formation. Some significant activity was detected at 10(-11) mol/L, and activity was lost at 10(-12) mol/L. In contrast, rLF had no significant activity at 10(-8) to 10(-16) mol/L. rHF was significantly active against mouse bone marrow CFU-GM to concentrations as low as 10(-8) to 10(-9) mol/L. The inhibitory activity of rHF was inactivated with three different monoclonal antibodies recognizing the heavy subunit of ferritin, but not with two monoclonal antibodies recognizing the light subunit of ferritin. The inhibitory activity of rHF was similar in the absence or presence of serum, monocytes, and T lymphocytes. We and others have shown an association of a glycosylated natural acidic isoferritin (AIF) with inhibitory activity, but since the rHF was expressed in Escherichia coli and did not bind to concanavalin A, glycosylation of AIF is not an absolute prerequisite for this activity. These results demonstrate that rHF has suppressive activity in vitro and substantiate our original observations using purified natural acidic isoferritins.
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PMID:The influence of purified recombinant human heavy-subunit and light-subunit ferritins on colony formation in vitro by granulocyte-macrophage and erythroid progenitor cells. 349 Aug 84

Acidic isoferritins have been previously found to be highly potent inhibitors of hematopoietic progenitors at concentrations of 10(-16) to 10(-18) mol/L, and it has been suggested that acidic isoferritin inhibitory activity plays a role in the regulation of normal hematopoiesis and also in the pathogenesis of leukemia. To characterize the ferritin species that affect the in vitro growth of human colony-forming unit-granulocyte-macrophage (CFU-GM), we tested different preparations of basic (L-subunit-rich) and acidic (H-subunit-rich) isoferritins. Three preparations of human liver (basic) ferritin did not show any effects on CFU-GM growth at concentrations up to 10(-9) mol/L, irrespective of the degree of glycosylation. Acidic isoferritins were purified both from HeLa cells and human heart. HeLa cell ferritin did not affect in vitro colony formation. One of two preparations of human heart ferritin, containing 5% glycosylated ferritin, showed a mean inhibition of 26% +/- 8% of the control at 10(-9) mol/L (P less than .02), whereas the other preparation, which contained no glycosylated ferritin, did not show any effect of CFU-GM growth. A preparation enriched for glycosylated acidic isoferritins from human heart was found to produce a mean inhibition of 32% +/- 11% of the control at 10(-9) mol/L (P less than .01), whereas another one was ineffective. A significant part of the inhibitory activity was removed by preincubation with the monoclonal antibody 2A4 directed against human heart ferritin. The present findings indicate that basic isoferritins, ie, the predominant ferritin type in human blood, have no effect on the growth of human CFU-GM, and this is in keeping with indirect clinical evidence. Inhibition of colony formation may be obtained by some preparations of acidic isoferritins that are rich in H subunits and bind to concanavalin A. The mechanism(s) responsible for this are not clear, but the effective concentrations are higher than those found in human blood both under normal conditions and in leukemia. At present, the physiologic significance of the observed inhibitory activity is uncertain.
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PMID:Effect of acidic and basic isoferritins on in vitro growth of human granulocyte-monocyte progenitors. 394 47

The relationship between Ia antigens on mouse resident peritoneal macrophages and the ability of lactoferrin (LF) to inhibit the production of granulocyte-macrophage colony stimulatory factors (GM-CSF) from these cells was investigated. Detection of the suppressive influence of LF on release of GM-CSF from greater than or equal to 10(5) macrophages/ml/plate required that the conditioned media being assessed for GM-CSF be prepared in the presence of indomethacin and/or be preincubated with anti-ferritin antiserum to respectively stop production of E-type prostaglandins and to remove acidic isoferritin-inhibitory activities that can mask the effects of LF. Treatment of mouse macrophages with monoclonal antibodies to the I-A and I-E/C subregions of Ia antigens in a complement C-dependent cytotoxicity assay killed less than 15% of the cells, but removed all Ia antigen+ macrophages and reduced GM-CSF production by approximately 50%. LF decreased GM-CSF production by untreated macrophages by approximately 50%, but had no effect on macrophages insensitive to treatment with anti-Ia plus C. Macrophages left at 37 degrees C for 5 and 24 hr were not killed by treatment with monoclonal anti-Ia plus C and GM-CSF production by these macrophages was not suppressed by LF. Treatment of macrophages with monoclonal anti-H-2K or anti-Mac-1 plus C reduced GM-CSF production greater than 95%. Anti-I-A, -I-E/C, -H-2K, or -Mac-1, in the absence of C, had no effect on viability of macrophages or on production of GM-CSF, but anti-I-A and -I-E/C each blocked the inhibitory action of LF. Lower concentrations of these antibodies could block the action of LF when anti-I-A and anti-I-E/C were mixed together better than when they were each used separately. The removal of Thy-1.2+ cells from unseparated or adherent peritoneal cells resulted in populations of cells that were up to 100% positive for nonspecific esterase, and did not influence GM-CSF production from these cells, the reduction of GM-CSF from these cells by LF, or the reduction of GM-CSF by the removal of Ia antigen+ cells. The results were similar whether or not T cells were removed from the assay marrow by treatment with antibodies Ly-1.1, Ly-2.2, and Qa4 plus C.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Lactoferrin acts on I-A and I-E/C antigen+ subpopulations of mouse peritoneal macrophages in the absence of T lymphocytes and other cell types to inhibit production of granulocyte-macrophage colony stimulatory factors in vitro. 614 10

It has been suggested that acidic isoferritins play a major role in the regulation of human granulocyte-macrophage (CFU-GM) proliferation. Such regulatory isoferritins are said to occur in some human tissues including both leukaemic and normal leucocytes, and certain established cell lines. They are glycosylated and bind to Con A. Extracts from HL-60, U-937 and K-562 cell lines are said to contain inhibitory activity but only in HL60 cells is the activity neutralized by antibody to acidic isoferritins. The properties of ferritin from these cell lines have been investigated. HL60 and U-937 extracts contained predominantly basic (spleen-type) isoferritins and K-562 extracts predominantly acidic (heart-type) isoferritins on immunoradiometric assay. None of the ferritin bound to Con A. On anion exchange chromatography ferritin from U-937 was basic in character, that from K-562 was acidic and HL-60 contained a variety of isoferritins. The identification of glycosylated acidic isoferritins as inhibitors of granulopoiesis appears to be an oversimplification and the classification of isoferritins on the basis of two subunit types may also need revision.
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PMID:Biochemical and immunological characteristics of ferritin from HL-60, U-937 and K-562 cell lines: implications for haemopoietic regulation. 654 90


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