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

• 批准号: 7829408
• 负责人: Osamu Tanabe
• 金额: $ 49.28万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7829408
• 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

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 ¿-type globin gene regulation. Such agents can be potentially applied to the treatment of ¿-globin disorders: sickle cell disease (SCD) and ¿- thalassemia. Since fetal 3-globin chains inhibit red cell sickling in SCD, therapeutic agents that increase 3-globin production are predicted to ameliorate both the symptoms and pathophysiology associated with the disease. Recent efforts in drug therapy for ¿-thalassemia have also focused on stimulation of 3-globin gene expression, but with only limited success. Because the effects of 3-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 3-globin inducing agents are needed. This proposal is focused on developing novel classes of therapeutic agents that inhibit a specific repressor of human 3-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 ¿-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 3-globin expression as an initial step toward therapeutic application for the treatment of SCD and ¿-thalassemia. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to develop novel drugs that can be safely used to treat patients with sickle cell disease (SCD) or 2-thalassemia. SCD affects 70,000-90,000 people in the U.S., and millions worldwide, causing severe pain, organ damage, and premature death (patients commonly die in their 40s). Severe forms of 2-thalassemia affect 800-1,000 people in North America, and 60,000 newborns annually worldwide, causing severe anemia that requires life-long blood transfusion for survival. Currently, only a few drugs are available to treat SCD, and these only modestly ameliorate the symptoms in only about half of the patients, but there are no current treatments for severe forms of 2-thalassemia. The only therapeutic option to cure these devastating diseases is stem cell transplantation that is often hampered by risk of therapy-related death, high cost, and lack of donor availability. We propose to develop a drug that acts on a specific protein that our work previously showed inhibits fetal hemoglobin production.

描述（由申请人提供）：本提案的目的是开发新颖的定制药物，通过重编程型珠蛋白基因调控，诱导成人造血干细胞产生人类胎儿红细胞。这些药物可能用于治疗-珠蛋白疾病：镰状细胞病（SCD）和-地中海贫血。由于胎儿3-珠蛋白链抑制SCD中的红细胞镰状细胞，预计增加3-珠蛋白产生的治疗药物可以改善与该疾病相关的症状和病理生理。最近在地中海贫血的药物治疗方面的努力也集中在刺激3-珠蛋白基因表达上，但收效甚微。由于3-珠蛋白诱导剂如羟基脲、5-氮杂胞苷和丁酸盐的作用是通过非特异性细胞毒性或表观遗传染色质修饰的全局变化介导的，这些药物会引起各种不利的细胞和全身副作用。这些包括非选择性全局基因去抑制、快速增殖细胞死亡（引起骨髓抑制）、致癌性和致畸性。这些不良反应将限制这些药物的治疗剂量、应用和疗效。因此，需要更有效、更安全的3-珠蛋白诱导剂。该建议的重点是开发新型的治疗药物，抑制人类3-珠蛋白基因表达的特定抑制因子。TR2和TR4是没有任何已知配体的孤儿核受体，最近被发现是胚胎-和胎儿3-珠蛋白基因抑制因子，将成为分子干预治疗-珠蛋白疾病的杰出靶点。在本提案中，将采用两种不同的策略来调节TR2和TR4的活性。首先是开发高效的小干扰RNA （siRNA）双链，通过RNA干扰特异性地敲除TR2、TR4或其潜在的共调节蛋白。第二种策略是确定低分子量的化学配体，无论是合成的还是天然的，它们可以抑制TR2和TR4的阻遏活性，甚至可以将它们从阻遏物转化为激活物，正如许多其他核受体在配体结合时观察到的那样。为了检测配体，将开发一种快速、灵敏的基于细胞的检测方法，然后用于大规模随机合成化合物文库的高通量筛选，以及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鉴定。一旦这种抗TR2/TR4药物，无论是sirna还是化学配体，被开发出来，它们可以立即作为-珠蛋白疾病的直接或主要治疗药物。将探索从成人造血祖细胞体外分化的小鼠和人类红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3-珠蛋白表达的“胎儿”红细胞的能力，作为治疗应用于SCD和地中海贫血的第一步。