ERYTHROPOIETIN & REGULATION OF ERYTHROPOIESIS

本研究的目的是增进对生物多样性调节的了解。 红细胞生成及其在临床贫血中的应用 和红细胞增多症。我们已经提纯了人类的克隆形成单位--红系 (CFU-E)，并已确定这些细胞上的促红细胞生成素(EPO)受体。 我们现在建议净化血液爆裂形成单位-红系(BFU-E)和 BFU-E中EPO受体进化的时程测定 发展与差异化。我们还将确定 白细胞介素3(IL-3)粒细胞集落刺激因子， 粒细胞集落刺激因子与胰岛素样生长 胰岛素样生长因子I(IGF-I)对EPO受体的下调或上调作用。 我们还发现，当肿瘤坏死因子(TNF)和IL-1抑制 正常的人骨髓CFU-E发育，纯化的CFU-E不是 受制于这些因素。因此，肿瘤坏死因子和白介素1显然是作用于 辅助细胞产生一种因子，该因子被释放并抑制CFU-E。 我们将确定这些中间辅助细胞的身份， 提纯正在释放的因素，并测量其效果 因子对人CFU-E EPO受体的影响，以确定肿瘤坏死因子和/或白细胞介素1是否下调 模组EPO受体作为产生贫血的机制。 我们还将进一步研究红系中的EPO受体 差异化。一种异双官能团，光反应，可切割，碘化 交联剂将提供放射性EPO受体， 分子大小、等电点、糖基化和 磷酸化能力。将获得EPO受体基因，并将 测定促红细胞生成素和胰岛素样生长因子-I对大鼠成纤维细胞促红细胞生成素受体mRNA的影响 高度纯化的小鼠CFU-E分化。这些研究将 增强我们对由EPO控制的事件以及它们的知识 将提高我们对慢性病贫血的认识。他们 还应为进一步了解 可能发生的各种额外的临床贫血和红细胞增多症 通过正常的促红细胞生成素控制机制的故障。

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.