Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hematopoietic growth factors stem cell factor (SCF) and flt3 ligand (flt3L) are produced within the hematopoietic microenvironment in a membrane-bound and soluble isoform. To elucidate the relevance of the two isoforms in the network of early-acting cytokines, we examined the interaction of membrane-bound SCF with the soluble forms of SCF and flt3L in long-term cultures of human bone marrow cells. Feeder layers of the murine SCF-deficient Steel stromal cell line transfected with human cDNA stably expressing SCF as a transmembrane molecule were used to support growth of mononuclear cells and CD34+ progenitors derived from normal human bone marrow or from hypoplastic marrow of patients with aplastic anemia (AA). The output of nonadherent progenitor cells representing colony-forming units (CFU) and high-proliferative potential colony-forming cells (HPP-CFC) was scored weekly in secondary methylcellulose cultures; the number of colonies derived from long-term culture-initiating cells (LTC-IC) was determined in nonadherent and adherent cells at 5 weeks. Membrane-bound SCF expressed in the stromal layer was more effective than soluble SCF and soluble flt3L in maintaining clonogenic progenitors. Furthermore, the transmembrane form of SCF effectively synergized with both exogenously supplied factors, although the effect of flt3L was superior to the effect of soluble SCF. In cultures of normal bone marrow cells, addition of flt3L enhanced the total number of CFU and HPP-CFC-type progenitors, primarily of the granulocyte/macrophage lineage, by six- to ninefold after 3 weeks and of LTC-IC-derived colonies by 13-fold after 5 weeks of culture. In cultures of AA cells, both the number and the survival rate of clonogenic precursors were severely impaired even in the presence of flt3L, which, however, yielded a two- to sixfold enhancement of CFU and HPP-CFC numbers at 1 to 2 weeks. In comparison with the hematopoietic function of human Dexter-type stroma cultures, murine feeders expressing high levels of membrane-associated human SCF were equivalent in supporting hematopoiesis during the initial 3 to 4 culture weeks when supplemented with flt3L. These results demonstrate that soluble flt3L interacts with membrane-bound SCF in supporting the long-term growth of bone marrow progenitor cells. The hypothesis that SCF and flt3L function synergistically during the very early stages of human hematopoiesis is thereby reinforced.
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PMID:The membrane-bound isoform of stem cell factor synergizes with soluble flt3 ligand in supporting early hematopoietic cells in long-term cultures of normal and aplastic anemia bone marrow. 959 Jun 52

The aim of this article was to explore the pathogenetic differences, as well as to provide a new way for the differential diagnosis of these two diseases by comparative analysis of CD(34)(+) cells numbers and their surface expression of granulocyte colony-stimulating factor receptor (G-CSFR) and granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR) in patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS). Twenty-seven patients with AA, 45 patients with MDS, and 20 normal controls were enrolled in this study. The ratio of CD(34)(+) cells and their surface expression of G-CSFR and GM-CSFR were detected by flow cytometry (FCM). The ratio of CD(34)(+) cells in BMMNC of AA, MDS patients and controls were 0.2438 +/- 0.1129%, 2.1677 +/- 1.1345% and 1.0792 +/- 0.3221%, respectively. Compared with normal controls as well as MDS patients, the ratio of CD(34)(+) cells in BMMNC of AA was significantly reduced (P < 0.05). The ratio of CD(34)(+) cells in MDS was significantly elevated than controls (P < 0.05). The ratio of CD(34)(+) cells in BMMNC of MDS-RA and MDS-RAEB patients were 1.2821 +/- 0.4658% and 3.7729 +/- 2.3360%, respectively. Compared with normal controls and MDS-RA patients, the ratio of CD(34)(+) cells in MDS-RAEB was significantly elevated (P < 0.05). The ratio of CD(34)(+) cells in MDS-RA was significantly elevated than AA patients (P < 0.05). The surface expression of G-CSFR on CD(34)(+) cells of AA, MDS patients and controls were 34.402 +/- 21.8357%, 26.376 +/- 15.2895% and 21.443 +/- 7.4465%, respectively. The surface expression of G-CSFR on CD(34)(+) cells of MDS-RA and MDS-RAEB patients were 22.788 +/- 14.7628% and 30.682 +/- 15.5346%. The surface expression of GM-CSFR on CD(34)(+) cells of AA, MDS patients and controls were 6.5961 +/- 4.4322%, 18.2737 +/- 10.9841% and 4.2753 +/- 2.6249%, respectively. Compared with AA and controls, the expression of GM-CSFR in MDS patients was significantly elevated (P < 0.05). The surface expression of GM-CSFR on CD(34)(+) cells of MDS-RA and MDS-RAEB patients were 16.1625 +/- 6.9487% and 22.1003 +/- 14.2983%. In AA patients, the ratio of CD(34)(+) cells in BMMNC less than 0.1% accounts for 75% (6/8) SAA patients, compared with 10.55% (2/19) in CAA (P < 0.05). The detection of CD(34)(+) cells and their surface expression of granulocyte (macrophage) colony-stimulating factor receptors G (M)-CSFR in AA and MDS are helpful in the differential diagnosis or prognosis of these two disorders.
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PMID:Comparative analysis of G-CSFR and GM-CSFR expressions on CD34+ cells in patients with aplastic anemia and myelodysplastic syndrome. 1863 7