ERYTHROPOIETIN AND THE REGULATION OF ERYTHROPOIESIS

本研究的目的是为了提高人们对 红细胞生成及其在临床贫血中的应用 和红细胞增多症。 我们已经纯化了人类集落形成单位-红细胞 （CFU-E），并已鉴定出这些细胞上的促红细胞生成素（EPO）受体。 我们现在提出纯化红系血爆发形成单位（BFU-E）， 确定BFU-E期间EPO受体演变的时间过程 发展和分化。 我们还将确定 白细胞介素-3（IL-3）粒细胞集落刺激因子， 粒细胞巨噬细胞集落刺激因子与胰岛素样生长 促红细胞生成素-I因子（IGF-I）对EPO受体的下调或上调的作用。 我们还发现，当肿瘤坏死因子（TNF）和IL-1抑制 正常人骨髓CFU-E发育，纯化的CFU-E不 受这些因素的影响。 因此，TNF和IL-1显然作用于 辅助细胞产生释放并抑制CFU-E的因子。 我们将确定这些中间辅助细胞的身份， 净化正在释放的因子，并测量其效果。 因子对人CFU-E EPO受体的影响，以确定TNF和/或IL-1是否降低- 模块EPO受体作为产生贫血的机制。 我们还将进一步表征红系细胞中EPO受体的特征， 分化 一种异双功能、光反应性、可裂解、碘化的 交联剂将提供放射性EPO受体， 表征分子大小、等电点、糖基化和 磷酸化能力。 将获得EPO受体基因， 用于检测EPO和IGF-I对EPO受体mRNA的影响， 高度纯化的鼠CFU-E。 这些研究将 加强我们对EPO控制的事件的了解， 将增强我们对慢性疾病贫血的认识。 他们 还应提供一个坚实的信息基础， 可能发生的各种其他临床贫血和红细胞增多症 通过正常EPO控制机制的故障。

The aim of this research is to enhance understanding of the regulation of erythropoiesis and the application of this knowledge to clinical anemias and polycythemias. We have purified human colony forming units-erythroid (CFU-E) and have identified erythropoietin (EPO) receptors on these cells. We now propose to purify blood burst-forming units-erythroid (BFU-E) and determine the time course of the evolution of EPO receptors during BFU-E development and differentiation. We will also determine the effect of interleukin-3 (IL-3) granulocyte colony-stimulating factor, granulocytemacorphage colony-stimulating factor, and insulin-like growth factor-I (IGF-I) on down- or up-modulation of EPO receptors. We have also found that while tumor necrosis factor (TNF) and IL-1 depress normal human bone marrow CFU-E development, purified CFU-E are not inhibited by these factors. Thus, TNF and IL-1 are apparently acting on accessory cells to produce a factor that is released and inhibits CFU-E. We will determine the identity of these intermediate accessory cells, purify the factor that is being released, and measure the effect of this factor on human CFU-E EPO receptors to determine if TNF and/or IL-1 down- module EPO receptors as a mechanism for producing the anemia. We will also further characterize the EPO receptor during erythroid differentiation. A heterobifunctional, photoreactive, cleavable, iodinated cross-linker will provide radioactive EPO receptors which will be characterized for molecular size, isoelectric point, glycosylation and phosphorylation capacity. The EPO receptor gene will be obtained and will be used to measure the effect of EPO and IGF-I on EPO receptor mRNA in highly purified murine CFU-E as they differentiate. These studies will enhance our knowledge of the events that are controlled by EPO and they will enhance our under-standing of the anemia of chronic disorders. They should also provide a firm base of information for further understanding a wide variety of additional clinical anemia and polycythemias that may occur through the malfunction of normal EPO control mechanisms.