Jayaraman P S, Frampton J, Goodwin G
Department of Biochemistry, University of Bristol, University Walk, BS8 1TD, Bristol, UK.
Leuk Res. 2000 Dec;24(12):1023-31. doi: 10.1016/s0145-2126(00)00072-2.
Haematopoiesis involves the differentiation of a self-renewing stem cell into all of the lineages found in circulating blood. Myb-Ets transformed chicken blastoderm cells (MEPs) have many of the characteristics of multipotent haematopoietic cells and represent a useful model system for the study of haematopoiesis. The proline-rich homeodomain protein (PRH) has previously been shown to be expressed in the haematopoietic compartment. In this report we show that PRH mRNA and protein levels are down regulated as MEPs differentiate along the myelomonocytic and erythrocytic lineages. In contrast, PRH mRNA and protein levels remain high as MEPs differentiate toward the thrombocytic lineage. Over-expression of full length PRH in MEPs inhibits their transformation and/or proliferation. However, the over-expression of N-terminally truncated PRH proteins results in normally proliferating cells that are predominantly differentiated along the myelomonocytic and eosinophilic lineages. These results suggest that PRH plays a role in the proliferation and differentiation of haematopoietic cells.
造血作用涉及一个自我更新的干细胞分化为循环血液中发现的所有细胞谱系。Myb-Ets转化的鸡胚盘细胞（MEP）具有多能造血细胞的许多特征，是研究造血作用的有用模型系统。富含脯氨酸的同源结构域蛋白（PRH）先前已被证明在造血区室中表达。在本报告中，我们表明随着MEP沿髓单核细胞和红细胞谱系分化，PRH mRNA和蛋白水平下调。相反，随着MEP向血小板谱系分化，PRH mRNA和蛋白水平保持较高。在MEP中全长PRH的过表达抑制其转化和/或增殖。然而，N端截短的PRH蛋白的过表达导致正常增殖的细胞，这些细胞主要沿髓单核细胞和嗜酸性粒细胞谱系分化。这些结果表明PRH在造血细胞的增殖和分化中起作用。
