Extending GWAS at the BCL11A locus to novel therapeutics for HbF induction

描述(由申请人提供)： 这项拟议工作的目标是开发刺激成人红细胞中胎儿血红蛋白(HBF)产生的新方法。Hbf是一种已知的主要血红蛋白紊乱、镰状细胞性贫血和β-地中海贫血严重程度的修饰物。这些疾病影响着世界各地的无数人。由于NHLBI的一项重要任务是改善对这些疾病的治疗，因此拟议工作的目标应该是高度优先的。最近的研究表明，抑制蛋白BCL11A是成人红细胞前体细胞中HBF表达的主要沉默因子。通过全基因组关联研究，BCL11A基因被确定为候选调节基因。该项目有相互关联的目标，将用于验证BCL11A作为诱导HBF的治疗靶点。首先，我们将研究BCL11A基因中的单核苷酸多态(SNPs)影响BCL11A本身表达的机制。这将演示SNP是如何控制该基因座的。其次，将通过实验来评估BCL11A作为HbF调节因子的特异性。具体地说，将测定BCL11A表达下调的成年红系细胞的基因表达谱，并与BCL11A的基因组染色质占有率进行比较。这些实验将确定除HBF外，受BCL11A基因敲除影响的蛋白质的数量，以及BCL11A抑制红系细胞的潜在“非靶点”效应。第三，将探索BCL11A表达或功能的治疗调节方法。这些研究将包括高通量筛选在红系细胞中模拟BCL11A基因敲除的小分子或药物，开发旨在使BCL11A基因失活的工程锌指蛋白，以及测试可能干扰BCL11A功能的稳定螺旋肽。这些努力应该建立实验平台，为随后的患者临床试验识别和验证新的治疗药物提供便利。 公共卫生相关性： 遗传性血红蛋白疾病(镰状细胞病和地中海贫血)是一种贫血，对全世界无数人的健康造成不利影响。由于在成人中维持出生前表达的一种形式的血红蛋白，称为胎儿血红蛋白(HBF)，可以减轻这些疾病的严重性，因此重新激活成人类型的红细胞中的HBF是一个重要的治疗目标。这项拟议的研究重点是如何干扰HBF的主要沉默子，HBF是一种最近发现的蛋白质BCL11A，旨在开发遗传性贫血的新疗法。

DESCRIPTION (provided by applicant): The goal of the proposed work is the development of novel approaches to the stimulation of fetal hemoglobin (HbF) production in red blood cells of adults. HbF is a known modifier of the severity of the major hemoglobin disorders, sickle cell anemia and beta-thalassemia. These diseases affect numerous individuals worldwide. As an important mission of the NHLBI is improved treatment of these conditions, the goal of the proposed work should be of high priority. Recent work has demonstrated that the repressor protein BCL11A is a major silencer of HbF expression in adult red cell precursors. The BCL11A gene was identified as a candidate regulator through genome-wide association studies (GWAS). The project has interrelated goals that will serve to validate BCL11A as a therapeutic target for HbF induction. First, the mechanism by which single nucleotide polymorphisms (SNPs) in the BCL11A gene influence the expression of BCL11A itself will be examined. This will demonstrate HOW SNPs control the locus. Second, experiments will be employed to assess the specificity of BCL11A as a regulator of HbF. Specifically; the gene expression profile of adult erythroid cells in which BCL11A expression is knocked-down will be determined and compared with the genomic chromatin occupancy of BCL11A. These experiments will define the number of proteins other than HbF that are affected by BCL11A knock-down and also potential "off-target" effects of BCL11A inhibition in erythroid cells. Third, approaches to therapeutic modulation of BCL11A expression or function will be explored. These studies will include highthroughput screening for small molecules or drugs that mimic the knock-down of BCL11A in erythroid cells, the development of engineered zinc finger proteins designed to inactivate the BCL11A gene, and testing of stabilized helical peptides that might interfere with BCL11A function. These efforts should establish experimental platforms that will facilitate the identification and validation of new therapeutics agents for subsequent clinical trials in patients. PUBLIC HEALTH RELEVANCE: Inherited disorders of hemoglobin (sickle cell disease and the thalassemias) are anemias that adversely affect the health of countless individuals worldwide. As maintenance of a form of hemoglobin that is expressed prior to birth, called fetal hemoglobin (HbF), in the adult lessens the severity of these conditions, reactivation of HbF in adult type red blood cells is an important therapeutic goal. The proposed research focuses on how to interfere with the major silencer of HbF, a recently identified protein BCL11A, in an effort to develop new treatment for inherited anemias.