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（由适用提供）：镰状细胞疾病（SCD）与其他血红蛋白病（α-和β-地中海贫血）纳入时是人类中最常见的遗传疾病，并且大多数患者一生都需要治疗。当前的治疗方式要么具有使人衰弱的副作用，要么对受影响的个体的主要子集无效。仅美国SCD患者的医疗保健费用超过11亿美元/年度（CA。2008）。临床和实验研究都发现，即使是γ-珠蛋白表达的适度增加也可以减轻SCD中的症状，器官病理和疼痛。我们的实验室确定了负责ε-和γ-球蛋白基因表达的大分子反射剂复合物，该复合物的核心DNA结合成分是孤儿核受体TR2（NR2C1）和TR4（NR2C2）。当抑制这种复制器复合物时，γ-球蛋白的表达增加并减少了SCD的病理生理表现，从而使其成为治疗性发育的有吸引力的靶标。但是，除了所有二聚体受体物种（即TR2同二聚体，TR4同型二聚体或TR2/TR2杂化二聚体）的转录靶标和全基因组范围的结合外，除了ε-和γ-球蛋白基因外，每种物种都会激活或复制erythroid转录（例如，相互差异）（例如未知。我们的总体假设是，TR2和TR4均型和异二聚体形成不同的转录复合物，以激活或反映红细胞分化过程中靶基因转录。具体的目标1将通过阶段纯化的鼠类红斑祖细胞中的芯片序列方法检查TR2-和TR4-同型二聚体和异二聚体的直接基因组结合位点以及异二聚体的转录靶标，并利用熔融二聚体来检查特定的二聚体活性。在特定的目标2中，我们将检查TR2和TR4同二聚体和异二聚体复合物与红细胞中DNA的结合的机制。该项目的发现将对正常红细胞生成期间TR2和TR4的功能有更深入的了解，并对控制球蛋白基因表达的分子机制有了更好的了解。反过来，这些发现将有助于与治疗血红蛋白病的当前药物相比，具有更特异性和负面影响的新治疗剂的发展。