Characterization of TR2 and TR4 homodimer and heterodimer transcriptional mechanisms during erythropoiesis.

红细胞生成过程中 TR2 和 TR4 同二聚体和异二聚体转录机制的表征。

基本信息

批准号：
9049933
负责人：
Mary Patricia Lee
金额：
$ 5.61万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-01 至 2018-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9049933
关键词：
Acute Pain Adult Adverse effects Affect Binding Binding Sites Biochemical Blood Transfusion Cell physiology ChIP-seq Child Clinical Clinical Research Complex DNA DNA Binding Development Direct Repeats Disease Embryo Epigenetic Process Erythrocytes Erythroid Erythroid Cells Erythroid Progenitor Cells Erythropoiesis Event FDA approved Fetal Hemoglobin Gene Expression Gene Targeting Genes Genetic Transcription Genomics Globin Heart failure Hematological Disease Hemoglobinopathies Homo Human Inherited Iron Overload Ischemia Ischemic Stroke Knockout Mice Laboratories Life Macromolecular Complexes Mediating Medical Care Costs Modality Molecular Mus Mutation Necrosis Nuclear Orphan Receptor Organ Pain Pathology Patients Pharmaceutical Preparations Proteins Repression Risk Sickle Cell Sickle Cell Anemia Site Sorting - Cell Movement Specificity Staging Symptoms Testing Thalassemia Therapeutic beta Thalassemia carcinogenicity chromatin modification cytotoxicity dimer epsilon Globin erythroid differentiation fetal gamma Globin genome-wide hydroxyurea in vivo insight man novel therapeutics orphan nuclear receptor TR2 promoter protein complex public health relevance pulmonary arterial hypertension receptor reduce symptoms research study targeted treatment therapeutic development

项目摘要

DESCRIPTION (provided by applicant): Sickle cell disease (SCD) when included with other hemoglobinopathies (α- and β-thalassemia) are the most common inherited diseases in man, and most often patients require treatment for their entire lives. Current treatment modalities either have debilitating side effects or are not effective for a major subset of affected individuas. The annual cost of medical care of SCD patients in the US alone exceeds $1.1 billion/annum (ca. 2008). Both clinical and experimental studies have found that even a modest increase in γ-globin expression can alleviate symptoms, organ pathology, and pain in SCD. Our laboratory identified a macromolecular repressor complex responsible for repression of the ε- and γ-globin genes, and the core DNA binding components of this complex are the orphan nuclear receptors TR2 (NR2C1) and TR4 (NR2C2). When this repressor complex is inhibited, the expression of γ-globin increases and the pathophysiological manifestations of SCD were reduced, thus making it an attractive target for therapeutic development. However, other than the ε- and γ-globin gene the transcriptional targets and genome-wide binding of all dimeric receptor species (i.e. TR2 homodimer, TR4 homodimer, or TR2/TR4 heterodimer) or the actions by which each species activates or represses erythroid transcription (e.g. their differential association with co-activatrs and co-repressors) are largely unknown. Our overarching hypothesis is that TR2 and TR4 homo- and heterodimers form distinct transcriptional complexes to either activate or repress target gene transcription during erythroid differentiation. Specific aim 1 will examine the direct genomic binding sites and transcriptional targets of TR2- and TR4- homodimers and heterodimers through a ChIP-seq approach in stage purified murine erythroid progenitor cells, and utilization of fused dimers to examine specific dimer activity. In Specific aim 2, we will examine the mechanisms that direct the binding of TR2 and TR4 homodimers and heterodimer complexes to DNA in erythrocytes. The discoveries from this project will provide a deeper understanding of the functions of TR2 and TR4 during normal erythropoiesis, and provide a better understanding of the molecular mechanisms controlling globin gene expression; in turn, these findings will aid in the development of new therapeutics with greater specificity and fewer negative side effects than current medications used to treat the hemoglobinopathies.

描述（由申请人提供）：镰状细胞病（SCD）与其他血红蛋白病（α-和β-地中海贫血）一起是人类最常见的遗传性疾病，大多数患者需要终生接受治疗。仅在美国，SCD 患者的年度医疗费用就超过 11 亿美元（约 11 亿美元）。 2008)。临床和实验研究都发现，即使是适度增加 γ-珠蛋白表达也可以缓解 SCD 的症状、器官病理和疼痛。我们的实验室发现了一种负责抑制 ε-和 γ-珠蛋白的大分子抑制复合物。基因，该复合物的核心 DNA 结合成分是孤儿核受体 TR2 (NR2C1) 和 TR4 (NR2C2)，当该阻遏复合物受到抑制时， γ-珠蛋白增加，SCD 的病理生理学表现减少，从而使其成为治疗开发的有吸引力的靶点。然而，除了 ε- 和 γ-珠蛋白基因之外，所有二聚体受体物种（即 γ-珠蛋白基因）的转录靶点和全基因组结合。 TR2 同二聚体、TR4 同二聚体或 TR2/TR4 异二聚体）或每个物种激活或抑制红细胞转录的作用（例如，它们与我们的总体假设是 TR2 和 TR4 同二聚体和异二聚体形成不同的转录复合物，以在红系分化过程中激活或抑制靶基因转录。具体目标 1 将检查直接基因组结合位点。通过 ChIP-seq 方法在阶段纯化的鼠类红系祖细胞中实现 TR2- 和 TR4- 同二聚体和异二聚体的转录靶标，以及融合二聚体的利用在特定目标 2 中，我们将研究指导 TR2 和 TR4 同二聚体和异二聚体复合物与红细胞中 DNA 结合的机制。该项目的发现将有助于更深入地了解 TR2 和 TR4 的功能。正常红细胞生成期间，并提供对控制珠蛋白基因表达的分子机制的更好理解，这些发现反过来将有助于开发比现有药物具有更高特异性和更少副作用的新疗法；用于治疗血红蛋白病。