HRI-eIF2a Phosphorylation signaling in oxidative stress and erythropoiesis

氧化应激和红细胞生成中的 HRI-eIF2a 磷酸化信号传导

基本信息

批准号：
8829233
负责人：
JANE-JANE CHEN
金额：
$ 33.93万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-12 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8829233
关键词：
A Mouse Adult Affect Anemia BFU-E Basophilic Erythroblast Bone Marrow CD34 gene Cells Chronic Disease Clinical Development Disease Erythroblasts Erythrocytes Erythroid Erythropoiesis Etiology Fetal Hemoglobin Fetal Liver Gene Expression Genetic Translation Globin Health Heme Heme Iron Hemoglobin Hemoglobinopathies Human Incidence Infant Iron Iron deficiency anemia Laboratories Lead Malignant Neoplasms Maps Mediating Mediator of activation protein Mendelian disorder Messenger RNA Methods Molecular Molecular Profiling Mus Outcome Outcome Study Oxidative Stress Pathway interactions Patients Pharmaceutical Preparations Phosphorylation Phosphotransferases Process Production Pronormoblasts Proteins Regulation Research Ribosomes Role Severities Signal Transduction Sorting - Cell Movement Spleen Staging Stress Technology Testing Thalassemia Time Transcriptional Regulation Translating Translational Regulation Translations biological adaptation to stress density embryonic stem cell erythroid differentiation genome-wide genome-wide analysis in vivo iron deficiency mouse model novel progenitor

项目摘要

DESCRIPTION (provided by applicant): Our long-term objective for this proposed research is to contribute to the more comprehensive understanding of the regulation of hemoglobin synthesis and erythropoiesis under stress conditions and in red cell disorders. In this proposal, we focus on translational control by the heme-regulated eIF2¿ kinase (HRI) in oxidative stress and stress erythropoiesis. Our laboratory has demonstrated that HRI is necessary to reduce ineffective erythropoiesis and to maintain proper gene expression in erythroid precursors during iron deficiency. HRI is also essential for reducing the phenotypic severities of ¿-thalassemia. Phosphorylation of eIF2¿ by HRI not only inhibits translation globally, but also selectively increases the translation of ATF4 mRNA in primary erythroid precursors. This HRI-activated ATF4 stress response pathway is necessary to mitigate oxidative stress and to promote erythroid differentiation. Most recently, HRI-eIF2¿P pathway has been shown to induce fetal hemoglobin (HbF) production in human CD34+ cells undergoing erythroid differentiation. While transcriptional regulation during erythropoiesis has been studied extensively, much less is known about the role of translational control in this process. We hypothesize that eIF2 ¿P-mediated translation is necessary to mitigate oxidative stress and to promote erythroid differentiation during stress erythropoiesis. We will employ a recently developed genome-wide approach, ribosome profiling, to study translational regulation during normal and stress erythropoiesis in heme deficiency and in ¿-thalassemia. A novel line of erythroid-specific eIF2¿Ser51Ala knockin (erythroid- ¿A/A) mice, which are defective in eIF2¿P signaling specifically in the erythroid lineage, will be generated. Erythroblasts isolated by FACS sorting from fetal livers of wild type (Wt), Hri-/- and erythroid-A/A mice under iron sufficient and deficint conditions, will be used to study the role of heme, HRI and eIF2¿P in regulating in vivo translation genome-wide. In addition, ribosome profiling will also be performed in splenic basophilic erythroblasts of ¿-thalassemic mice. The outcomes of these proposed studies will elucidate the essential role of heme and eIF2¿P-mediated translation in erythropoiesis under stress conditions. This proposed research will also uncover novel molecular mechanisms in translational regulation and new proteins produced in the erythroid lineage during differentiation. The novel information obtained from these studies will advance the field of erythropoiesis greatly and will have a very significant impact on the development of new therapies for hemoglobinopathies.

描述（由申请人提供）：我们这项拟议研究的长期目标是有助于更全面地了解应激条件下和红细胞疾病中血红蛋白合成和红细胞生成的调节。在本提案中，我们重点关注翻译控制。由血红素调节的 eIF2¿氧化应激和应激性红细胞生成中的激酶（HRI）我们的实验室已经证明，HRI 对于减少无效红细胞生成和在铁缺乏期间维持红细胞前体中适当的基因表达也是必要的。 -eIF2 磷酸化。 HRI 不仅全局抑制翻译，而且还选择性地增加原代红细胞前体中 ATF4 mRNA 的翻译，这种 HRI 激活的 ATF4 应激反应途径对于减轻氧化应激和促进红细胞分化是必需的。 P 途径已被证明可诱导正在进行红细胞分化的人类 CD34+ 细胞产生胎儿血红蛋白 (HbF)，虽然红细胞生成过程中的转录调控已被广泛研究，但我们对 eIF2 翻译控制的作用知之甚少。 P 介导的翻译对于减轻氧化应激和促进应激性红细胞生成过程中的红细胞分化是必要的。我们将采用最近开发的全基因组方法（核糖体分析）来研究血红素缺乏和应激性红细胞生成过程中的翻译调节。 -地中海贫血。红细胞特异性 eIF2 的新系列。 Ser51Ala 敲入（红系- ¿A/A）小鼠，其 eIF2¿ 有缺陷在铁充足和缺铁条件下，通过 FACS 分选从野生型 (Wt)、Hri-/- 和红细胞-A/A 小鼠的胎儿肝脏中分离出的 P 信号传导将被用于研究。血红素、HRI 和 eIF2 的作用¿ P 在全基因组范围内调节体内翻译此外，还将在 ¿ 的脾嗜碱性成红细胞中进行核糖体分析。 -地中海贫血小鼠。这些拟议研究的结果将阐明血红素和 eIF2 的重要作用。应激条件下红细胞生成过程中 P 介导的翻译也将揭示翻译调节的新分子机制以及分化过程中红细胞谱系中新产生的蛋白质。从这些研究中获得的新信息将极大地推进红细胞生成领域的发展，并对血红蛋白病新疗法的开发产生非常重大的影响。