GENE EXPRESSIONS DURING PROLIFERATION AND DIFFERENTIATION OF MYELOID CELIS IN SEVERE CONCENITAL NEUTROPENIA

最近，中性粒细胞弹性蛋白酶（NE）基因ELA 2突变，已报告在严重的先天性中性粒细胞增多症（SCN）患者。我们研究了SCN患者原始髓系祖细胞在增殖和分化过程中颗粒组成基因的表达。基于CD 34和G-CSF受体（G-CSFR）的表达纯化骨髓中的原始髓样细胞。SCN患者的CD 34 ^+ / G-CSFR^+细胞（而非CD 34 ^+ / G-CSFR细胞）在无血清培养中对单独的G-CSF和联合造血因子的反应中显示出GM集落形成和缺陷增殖的数量减少。CD 34 ^+ / G-CSFR^+细胞表达低水平的颗粒成分mRNA。在正常人中，当G-CSF诱导细胞向髓系分化时，初级颗粒酶基因的转录水平逐渐增强，然后下降。但在SCN患者增殖早期转录水平的上调明显低于正常人。此外，在SCN患者中未明确观察到这些酶translucin的下调。SCN患者与正常人之间乳铁蛋白基因的表达无明显差异。这些结果提示，SCN患者骨髓细胞原代颗粒成分转录调控异常可能与SCN患者骨髓细胞增殖和分化障碍有关。

Recently, mutations in the neutrophil elastase (NE) gene, ELA2, have been reported in patients with severe congenital Neutrogena (SCN). We studied the expression of granule constituent genes in primitive myeloid progenitor cells during proliferation and differentiation in patients with SCN. Primitive myeloid cells in the bone marrow were purified based on the expression of CD34 and G-CSF receptor (G-CSFR). The CD34^+ / G-CSFR^+ cells, but not the CD34^+ / G-CSFR cells, of SCN patients showed a reduced number of GM-colony formation and defectives proliferation in response to G-CSF alone and to the combinations of hematopoietic factors in serumdeprived culture. The CD34^+ / G-CSFR^+ cells expressed low levels of the granule constituent mRNAs. The transcription levels of primary granule enzyme genes were gradually enhanced and then decreased when cells were induced toward myeloid lineage in the presence of G-CSF in normal subjects. However, the up-regulation of the transcription in the early stage of proliferation of SCN patients was significantly lower than those of normal subjects. Furthermore, the down-regulation of these enzyme transcriptions was not clearly observed in SCN patients. No differences in the expressions of lactoferrin gene were seen between normal subjects and patients with SCN. These results suggest that the abnormal regulation of the transcription in primary granule consitituents may play a potential role in the defective proliferation and differentiation of myeloid lineage in patients with SCN.