CONTROL OF TRANSCRIPTION OF ERYTHROPOIETIN

肾脏通常被认为是主要的生产基地， 促红细胞生成素（Epo），红细胞生成的生理调节剂。 实验性缺氧导致肾脏Epo mRNA水平急剧增加 和血清促红细胞生成素细胞氧传感机制，Epo特异性 转录激活因子，和必要的基因组序列 对EPO调节的作用尚未阐明。1986年，我们分离出两个细胞， 不适当地合成Epo的线。来解释异常的促红细胞生成素 转录和获得有关EPO调节的新信息，我们将 研究了以下三个假设：（1）。基因组改变 去除负调控序列或插入正调控序列 序列; 2）Epo mRNA稳定性增加，3）推定的Epo 转录激活因子被不适当地表达。 我们已经通过限制性映射探索了第一个模型， 发现了两种细胞系中Epo基因的基因组改变。在 在一种情况下，改变是Epo编码序列的上游。电流 克隆和测序实验有望揭示 Epo重排的性质。在第二个项目中，我们试图 鉴定调节Epo转录以响应 体外氧浓度的变化。我们将评估Epo诱导 在NIH最近分离的几种新的人类肾脏细胞系中。

The kidney is generally recognized as the major production site of erythropoietin (Epo), the physiologic regulator of red cell production. Experimental hypoxia produces a sharp increase in kidney Epo mRNA levels and serum Epo. The cellular oxygen sensing mechanism, the Epo specific transcriptional activating factors, and the genomic sequences necessary for Epo regulation have not been elucidated. In 1986, we isolated two cell lines which inappropriately synthesized Epo. To explain the abnormal Epo transcription and gain new information concerning Epo regulation, we will investigate the following three hypotheses: 1). Genomic alterations removed negative regulatory sequences or inserted positive regulatory sequences; 2) Epo mRNA stability has increased, and 3) putative Epo transcriptional activating factors have been inappropriately expressed. We have explored the first model by restriction mapping and have discovered genomic alterations in the Epo genes from both cells lines. In one case, the alterations are upstream of Epo coding sequences. Current cloning and sequencing experiments are expected to reveal the precise nature of the Epo rearrangements. In a second project we are attempting to identify normal cells which adjust Epo transcription in response to changes in oxygen concentration in vitro. We will assess Epo inducibility in several new human kidney cell lines recently isolated at NIH.