Hofmann W K, Kalina U, Wagner S, Seipelt G, Ries C, Hoelzer D, Ottmann O G
Department of Hematology, Johann Wolfgang Goethe University Hospital, Frankfurt/Main, Germany.
Exp Hematol. 1999 Mar;27(3):395-400. doi: 10.1016/s0301-472x(98)00077-0.
Megakaryocytic differentiation of progenitor cells was investigated in nine patients with low-risk myelodysplastic syndromes (MDS) (eight refractor anemia [RA] and one RA with ringed sideroblasts [RARS] and five patients with high-risk MDS (two RA with excess of blasts [RAEB] and three RAEB in transformation [RAEB-T]). Bone marrow-derived CD34+ cells were enriched to a purity of 87% +/- 2% (mean +/- SEM) and assayed in short-term suspension cultures in the presence of 10 ng/mL of PEGylated recombinant human megakaryocyte (MK) growth and development factor (PEG-rHuMGDF) and in addition to 50 ng/mL stem cell factor and 10 ng/mL interleukin-3. Cells of the megakaryocytic lineage were identified by flow cytometric analysis of CD42b (GP1b) and mature MKs by morphologic criteria. Transcription of c-mpl receptor-specific mRNA in the CD34+ cells of these patients was investigated by full-length reverse transcriptase polymerase chain reaction of the p form of c-mpl as well as of the alternative splice product c-mpl k. CD34+ cells from seven healthy bone marrow donors served as controls. Differentiation along the MK pathway was stimulated in five patients with RA. C-mpl mRNA was expressed in the CD34+ cells in all cases. In three low-risk patients the capacity for in vitro MK growth was absent or minimal even though mRNA for c-mpl receptor was detected in the CD34+ cells of this group as well. In patients with high-risk MDS, PEG-rHuMGDF stimulated in vitro MK growth from CD34+ cells in only one of five cases. As in the patients with low-risk MDS, c-mpl mRNA for both c-mpl p and c-mpl k splicing products was detected. These results indicate that the in vitro response to stimulation with c-mpl ligand discriminates between two groups of patients with low-risk MDS and that the observed defect in megakaryocytic development is unrelated to the level of c-mpl expression in both low-risk and high-risk MDS.
研究了9例低危骨髓增生异常综合征（MDS）患者（8例难治性贫血[RA]和1例环形铁粒幼细胞性难治性贫血[RARS]）以及5例高危MDS患者（2例伴原始细胞增多的难治性贫血[RAEB]和3例转化中的RAEB[RAEB-T]）祖细胞的巨核细胞分化情况。将骨髓来源的CD34+细胞富集至纯度为87%±2%（均值±标准误），并在含有10 ng/mL聚乙二醇化重组人巨核细胞（MK）生长和发育因子（PEG-rHuMGDF），以及50 ng/mL干细胞因子和10 ng/mL白细胞介素-3的短期悬浮培养中进行检测。通过对CD42b（糖蛋白1b）的流式细胞术分析鉴定巨核细胞系细胞，并根据形态学标准鉴定成熟巨核细胞。通过对c-mpl p形式以及可变剪接产物c-mpl k进行全长逆转录聚合酶链反应，研究这些患者CD34+细胞中c-mpl受体特异性mRNA的转录情况。来自7名健康骨髓供体的CD34+细胞作为对照。5例RA患者的巨核细胞途径分化受到刺激。所有病例的CD34+细胞中均表达c-mpl mRNA。在3例低危患者中，即使在该组的CD34+细胞中检测到了c-mpl受体的mRNA，其体外巨核细胞生长能力也不存在或极低。在高危MDS患者中，PEG-rHuMGDF仅在5例中的1例中刺激了CD34+细胞的体外巨核细胞生长。与低危MDS患者一样，检测到了c-mpl p和c-mpl k剪接产物的c-mpl mRNA。这些结果表明，体外对c-mpl配体刺激的反应可区分两组低危MDS患者，并且观察到的巨核细胞发育缺陷与低危和高危MDS中c-mpl的表达水平无关。
