Molecular Pathogenesis of Diamond Blackfan Anemia

描述(申请人提供)：钻石黑扇贫血(DBA)是一种异质性疾病，患者存在纯红细胞再生障碍性疾病、先天性异常和癌症风险增加。核糖体蛋白亚基(RPS)19和11的突变已被描述。我们建议对RPS19和RPL11在斑马鱼以及在小鼠和人类造血模型系统中的缺陷所导致的分子通路进行表征，以了解DBA的发病机制。基于我们的初步数据，我们将研究RPS19和RPL11水平的降低如何改变P53蛋白网络，以及通过MDM2和其他调节因子对P53的调节。我们假设P53在发育过程中受到不同的调控。我们的结果和其他人发表的工作表明，p53在发育早期主要是转录调控的，但在更成熟或成年的细胞中是翻译后调控的。在特定的目标1中，我们将建立不同的RPS19或RPL11缺乏的斑马鱼模型，以研究P53相关蛋白在DBA和恶性转化中的作用。在特定的目标2中，我们将在体外和体内研究RPS19和RPL11缺陷的人和小鼠原代造血细胞中的P53信号通路。抑制素作为RPS19不足的下游靶点的作用也将被调查。在具体目标3中，我们将评估调节RPS19和RPL11基因敲除的造血细胞中P53活性的已知化合物作为治疗DBA的可能治疗方法。我们还建议使用斑马鱼胚胎来鉴定FDA批准的拯救RPL11表型的药物。通过这种方式，信号通路将与斑马鱼的发育异常和造血缺陷联系在一起。我们的研究将为DBA的分子发病机制提供新的见解，并为DBA患者的治疗开辟新的途径。 公共卫生相关性：该项目与公共卫生相关，因为它侧重于确定治疗DBA的新途径和开发新方法。因此，这项工作的结果将提高DBA患者的生活质量。

DESCRIPTION (provided by applicant): Diamond Blackfan Anemia (DBA) is a heterogeneous disease in which patients present with pure red cell aplasia, congenital abnormalities, and an increased risk of cancer. Mutations in ribosomal protein subunits (RPS) 19 and 11 have been described. We propose to characterize the molecular pathways resulting from deficiencies of RPS19 and RPL11 in the zebrafish and in mouse and human hematopoietic model systems to understand the pathogenesis of DBA. Based on our preliminary data, we will study how decreased levels of RPS19 and RPL11 alter the p53 network of proteins and the regulation of p53 through Mdm2 and other regulators. We hypothesize that p53 is differentially regulated during development. Our results and published work by others suggest that p53 is primarily regulated transcriptionally during early development, but post-translationally in more mature or adult cells. In Specific Aim 1, we will develop different zebrafish models with RPS19 or RPL11 insufficiency to characterize the role of p53 related proteins in DBA and malignant transformation. In Specific Aim 2, we will study p53 signaling pathways in human and mouse primary hematopoietic cells with RPS19 and RPL11 deficiency in vitro and in vivo. The role of inhibin as a downstream target of RPS19 insufficiency will also be investigated. In Specific Aim 3, we will evaluate known compounds regulating p53 activity in RPS19 and RPL11 knockdown hematopoietic cells as possible therapeutic approaches to treat DBA. We also propose to use zebrafish embryos to identify FDA approved drugs that rescue the RPL11 phenotype. In this manner, the signaling pathways will be linked to developmental anomalies in zebrafish and defects in hematopoiesis. Our studies will provide novel insights into the molecular pathogenesis of DBA and lead to new avenues for treatment of DBA patients. PUBLIC HEALTH RELEVANCE: This project is relevant to public health because it focuses on identifying new pathways and development of new approaches to treat DBA. Therefore, results from this work will improve the quality of life of DBA patients.