Institut für Physiologie, Universität Duisburg-Essen, Essen, Germany.
Blood. 2011 May 5;117(18):4905-14. doi: 10.1182/blood-2010-07-298083. Epub 2011 Mar 15.
Erythropoietin (EPO), the key hormone in red blood cell renewal, is mainly produced in the adult kidney. Anemia and hypoxia substantially enhance EPO expression to increase erythropoiesis. Investigations of the cellular physiology of renal EPO production have been hampered by the lack of an adequate human cell line. In the present study, we present the human kidney cell line REPC (for renal Epo-producing cells), established from an explanted human kidney exhibiting EPO gene expression and release of the EPO protein in an oxygen-dependent manner. Hypoxic induction of EPO mRNA showed the typical transient increase and peak in expression after 36 hours under continuous conditions of hypoxia. Bioactive EPO protein accumulated in the culture supernatant. The induction of EPO gene expression in REPCs critically depended on the activation of hypoxia-inducible transcription factors (HIFs). SiRNA treatment revealed that the expression of EPO was largely dependent on the activation of the transcription factor complex HIF-2. In addition, hepatic nuclear factor 4α was shown to be critically involved in hypoxia-induced renal EPO expression. Using the human kidney cell line REPC, we provide for the first time a powerful tool with which to study the cellular and molecular regulation of renal EPO production.
促红细胞生成素（EPO）是红细胞更新的关键激素，主要在成人肾脏中产生。贫血和缺氧会显著增强 EPO 的表达，从而增加红细胞生成。由于缺乏合适的人类细胞系，对肾脏 EPO 产生的细胞生理学的研究受到了阻碍。在本研究中，我们提出了从一个表现出 EPO 基因表达和 EPO 蛋白释放的人类肾脏中建立的人类肾脏细胞系 REPC（用于产生肾 Epo 的细胞），这种表达和释放是依赖于氧的方式。EPO mRNA 的缺氧诱导表现出典型的瞬时增加，并在缺氧的连续条件下 36 小时后达到表达高峰。生物活性的 EPO 蛋白在培养上清液中积累。REPC 中 EPO 基因表达的诱导严重依赖于缺氧诱导转录因子（HIFs）的激活。siRNA 处理表明，EPO 的表达在很大程度上依赖于转录因子复合物 HIF-2 的激活。此外，肝核因子 4α 被证明在缺氧诱导的肾脏 EPO 表达中起着关键作用。使用人类肾脏细胞系 REPC，我们首次提供了一种强大的工具，可用于研究肾脏 EPO 产生的细胞和分子调节。
