REGULATION OF ERYTHROPOIETIN GENE EXPRESSION IN FETUS

胎儿和成人的红细胞生成受激素调节 促红细胞生成素（Epo）。在成人中，Epo 在肾脏中产生。 埃波 据认为，胎儿体内的这些物质主要由肝脏产生 肾脏只有在妊娠晚期才成为重要的来源。 然而， 通过分子技术，Epo 基因的高水平表达 在整个妊娠期胎儿肾脏中发现，而 Epo 基因 胎儿肝脏中的表达较低。 此外，新的研究表明 胎盘是胎儿组织，产生 EPO。 哪些因素 刺激红细胞生成素生成的因素有缺氧和贫血。 然而， 缺氧贫血对Epo基因影响的特点 尚未在胎儿中检查表达。 拟议的研究 旨在探索 Epo 基因表达的调控和 结合生理学测定羊胎儿血浆 Epo 浓度 和分子方法。 具体目标 1 将建立正常 胎盘、胎儿肝脏和肾脏中 Epo 基因的表达模式 从妊娠 50 天到足月（150 天）。 北方人的技术 分析和竞争性逆转录聚合酶链 反应将用于 Epo 信使 RNA 的定量 （mRNA）。 表达 Epo mRNA 的细胞类型的定位 蛋白质将通过原位的方法完成 杂交和免疫组织化学。假设每个 组织在整个妊娠期表现出不同的模式。 具体目标 2 将 探讨母体低氧血症引起胎儿缺氧对胎儿的影响 胎儿肾脏、肝脏和胎盘中 Epo mRNA 丰度 妊娠100至150天。 假设 Epo 基因表达 胎盘和胎儿肾脏的增强程度比 肝脏。 具体目标 3 将探索 Epo 基因表达反应 100-150天胎儿贫血引起的缺氧 妊娠。 假设胎儿贫血会诱导 Epo mRNA 肾脏和肝脏，但不是胎盘。 我们的总体假设是 胎盘、胎儿肝脏和肾脏差异表达 Epo 整个妊娠期以及缺氧诱导 Epo 基因表达 每个组织中的情况取决于缺氧的类型。 这些研究是 意义重大，因为它们可以显着提高我们的理解 胎儿中 EPO 和红细胞生成的调节 很重要，因为它们可以帮助改善诊断和治疗 患有贫血和/或溶血病的人类胎儿和新生儿， 从而改善围产期结局。

Erythropoiesis in the fetus and adult is regulated by the hormone erythropoietin (Epo). In the adult, Epo is produced in the kidney. Epo in the fetus is believed to be produced mainly by the liver, with the kidneys becoming an important source only late is gestation. However, with molecular techniques, high levels of Epo gene expression are found in the fetal kidney throughout gestation whereas Epo gene expression in the fetal liver is low. Further, new studies suggest that the placenta, which is fetal tissue, produces Epo. The factors which stimulate Epo production are hypoxia and anemia. However, the characteristics of the hypoxic and anemic effects on Epo gene expression have not been examined in the fetus. The proposed studies are designed to explore the regulation of Epo gene expression and plasma Epo concentration in the ovine fetus by combining physiological and molecular approaches. Specific Aim 1 will establish the normal patterns of Epo gene expression in placenta, fetal liver and kidneys from 50 days gestation to term (150 days). The techniques of Northern analysis and competitive reverse transcription-polymerase chain reaction will be used for the quantification of Epo messenger RNA (mRNA). The localization of the cell types which express Epo mRNA and protein will be accomplished by the methods of in situ hybridization and immunohistochemistry. The hypothesis is that each tissue displays different patterns across gestation. Specific Aim 2 will explore the effects of fetal hypoxia induced by maternal hypoxemia on Epo mRNA abundance in kidney, liver and placenta of fetuses from 100 to 150 days gestation. The hypothesis is that Epo gene expression will be enhanced more in the placenta and fetal kidney than in the liver. Specific Aim 3 will explore Epo gene expression responses to hypoxia induced by fetal anemia in fetuses from 100-150 days gestation. The hypothesis is that fetal anemia induces Epo mRNA in the kidney and liver but not the placenta. Our overall hypothesis is that the placenta, fetal liver and kidney differentially express Epo across gestation and that the hypoxic induction of Epo gene expression in each tissue depends on the type of hypoxia. These studies are significant because they could significantly improve our understanding of the regulation of Epo and red cell production in the fetus and are important because they could help improve the diagnosis and treatment of human fetuses and neonates with anemia and/or hemolytic disease, thereby improving perinatal outcome.