Reactivation of Fetal Gamma-globin Genes for the Treatment of Beta-globin Disorde

胎儿 γ 珠蛋白基因的再激活治疗 β 珠蛋白紊乱

基本信息

批准号：
7938699
负责人：
Osamu Tanabe
金额：
$ 49.15万
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：
2009
资助国家：
美国
起止时间：
2009-09-30 至 2012-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7938699
关键词：
Acute Adopted Adult Adverse effects Affect Affinity Anemia Antineoplastic Agents Azacitidine Biological Assay Biological Models Blood Transfusion Blood flow Bone Marrow Suppression Butyrates CD34 gene Cells Cellular Stress Response Cessation of life Chemicals Child Chronic Clinical Research Clinical Trials DNA Methyltransferase Inhibitor DNA biosynthesis Data Deoxycytidine Development Disadvantaged Disease Embryo Epigenetic Process Erythrocytes Erythroid Erythroid Cells Exhibits Fetal Hemoglobin Fiber Frequencies Functional disorder Gene Expression Gene Expression Regulation Generations Genes Global Change Globin Goals Hematopoietic Hematopoietic stem cells Hemoglobin Hemoglobin concentration result Hemolytic Anemia Histone Deacetylase Inhibitor Human Intervention Lead Libraries Life Ligand Binding Ligands Mass Spectrum Analysis Mediating Methods Missense Mutation Molecular Molecular Target Molecular Weight Mus Mutate Mutation Natural regeneration New Agents Newborn Infant North America Nuclear Orphan Receptor Nuclear Receptors Organ Pain Patients Pharmaceutical Preparations Pharmacologic Substance Pharmacotherapy Population Production Proliferating Proteins RNA Interference Repression Research Risk Safety Screening procedure Shapes Sickle Cell Sickle Cell Anemia Sickle Hemoglobin Small Interfering RNA Stem cell transplant Stem cells Symptoms Technology Testing Thalassemia Therapeutic Therapeutic Agents Therapeutic Intervention Tissue Extracts Volatile Fatty Acids Work base beta Globin carcinogenicity chromatin modification clinical effect clinical efficacy cost cytotoxic cytotoxicity dosage fetal gamma Globin genetic regulatory protein high throughput screening hydroxyurea in vivo knock-down mortality novel novel therapeutics orphan nuclear receptor TR2 polymerization premature prevent progenitor public health relevance sickling stem success

项目摘要

DESCRIPTION (provided by applicant): The aim of this proposal is to develop novel, tailored agents than can induce the generation of human fetal red blood cells from adult hematopoietic stem cells by reprogramming beta-type globin gene regulation. Such agents can be potentially applied to the treatment of gamma-globin disorders: sickle cell disease (SCD) and beta- thalassemia. Since fetal gamma-globin chains inhibit red cell sickling in SCD, therapeutic agents that increase gamma-globin production are predicted to ameliorate both the symptoms and pathophysiology associated with the disease. Recent efforts in drug therapy for beta-thalassemia have also focused on stimulation of gamma-globin gene expression, but with only limited success. Because the effects of gamma-globin inducers such as hydroxyurea, 5- azacytidine, and butyrates are mediated either through non-specific cytotoxicity or global changes in epigenetic chromatin modification, those agents would cause a variety of unfavorable cellular and systemic side effects. Those include non-selective global gene de-repression, death of rapidly proliferating cells (causing bone marrow suppression), carcinogenicity, and teratogenicity. Those adverse effects would limit therapeutic dosages, application, and efficacy of those agents. Therefore, more effective and safer gamma-globin inducing agents are needed. This proposal is focused on developing novel classes of therapeutic agents that inhibit a specific repressor of human gamma-globin gene expression. TR2 and TR4, orphan nuclear receptors without any known ligand, have been recently identified as embryonic ¿- and fetal 3-globin gene repressors, and would be outstanding targets for molecular intervention therapy for ¿-globin disorders. In this proposal, two different strategies will be adopted to modulate the activity of TR2 and TR4. The first will be to develop highly efficient small interfering RNA (siRNA) duplexes that specifically knock-down TR2, TR4, or their potential co-regulatory proteins by RNA interference. The second strategy will be to identify low-molecular-weight chemical ligands, either synthetic or natural, that can inhibit the repressor activity of TR2 and TR4, or even convert them from repressors to activators as is observed with many other nuclear receptors upon ligand binding. To detect ligands, a rapid, sensitive cell-based assay will be developed and then used for high-throughput screening of a large-scale random synthetic compound library, as well as for screening of various mouse tissue extracts to search for natural ligands, which will be then affinity-purified and identified by mass spectrometry. Once such anti- TR2/TR4 agents, either siRNAs or chemical ligands, are developed, they could immediately serve as either direct or lead therapeutic agents for beta-globin disorders. Both primary mouse and human erythroid cells differentiated ex vivo from adult hematopoietic progenitors will be explored as possible model systems to test those agents for their ability to induce "fetal" erythroid cells with high-level gamma-globin expression as an initial step toward therapeutic application for the treatment of SCD and beta-thalassemia.

描述（由申请人提供）：本提案的目的是开发新颖的、定制的试剂，通过重编程β型珠蛋白基因调控，诱导成人造血干细胞产生人类胎儿红细胞。此类试剂具有潜在的应用前景。用于治疗γ-珠蛋白疾病：镰状细胞病（SCD）和胎儿β-地中海贫血由于γ-珠蛋白链抑制SCD中的红细胞镰状化，因此治疗药物可增加γ-珠蛋白的产生。预计可以改善与该疾病相关的症状和病理生理学。最近对β-地中海贫血的药物治疗也集中在刺激γ-珠蛋白基因表达上，但效果有限，因为γ-珠蛋白诱导剂的作用有限。由于羟基脲、5-氮杂胞苷和丁酸盐是通过非特异性细胞毒性或表观遗传染色质修饰的整体变化介导的，这些药物会导致多种不利的细胞毒性。这些副作用包括非选择性整体基因去抑制、快速增殖细胞死亡（导致骨髓抑制）、致癌性和致畸性，因此这些副作用将限制这些药物的治疗剂量、应用和疗效。，需要更有效和更安全的γ-珠蛋白诱导剂。该提案的重点是开发抑制人类γ-珠蛋白TR2和TR4孤儿核基因表达的新型治疗剂。没有任何已知配体的受体，最近被鉴定为胚胎 ¿ - 和胎儿 3-珠蛋白基因抑制子，将成为 ¿ 分子干预治疗的杰出靶点在该提案中，将采用两种不同的策略来调节 TR2 和 TR4 的活性，第一种策略是开发有效的小干扰 RNA (siRNA) 双链体，特异性敲除 TR2、TR4 或它们的潜在协同体。 -通过RNA干扰调节蛋白质。第二个策略是识别低分子量化学配体，无论是合成的还是天然的，它们可以抑制TR2和TR4的阻遏蛋白活性，甚至将它们从阻遏蛋白转化为阻遏蛋白。与许多其他核受体在配体结合时观察到的激活剂一样，为了检测配体，将开发一种快速、灵敏的基于细胞的测定法，然后用于大规模随机合成化合物库的高通量筛选。筛选各种小鼠组织提取物以寻找天然配体，然后将其亲和纯化并通过质谱法进行鉴定。一旦开发出此类抗TR2/TR4药物（无论是siRNA还是化学配体），它们就可以立即用作直接配体。或引导β-珠蛋白疾病的治疗剂将探索从成体造血祖细胞离体分化的原代小鼠和人红系细胞作为可能的模型系统，以测试这些药物诱导具有高水平γ-珠蛋白的“胎儿”红系细胞的能力。表达作为治疗 SCD 和 β-地中海贫血的治疗应用的第一步。