Control of Telomere Homeostasis by Nucleotide Metabolism in Hematopoiesis

项目摘要/摘要： 端粒稳态对细胞复制能力和人类健康至关重要。端粒缩短 细胞复制，当非常短时，会引发衰老和停止细胞分裂。遗传性突变 端粒维持基因与包括儿童期发病在内的严重造血疾病有关 骨髓衰竭、再生障碍性贫血、骨髓增生异常综合征以及非造血疾病 包括肝硬变和肺纤维化。这些疾病统称为端粒生物学。 精神障碍(待定)。TBDS的治疗主要集中在支持性护理和骨髓或器官移植。 这往往会导致不良的结果，并使患者面临其他疾病表现的风险。以新的方式 从治疗上来说，延长端粒和治疗颅脑损伤是必要的。为了找出新的控制途径 人类端粒长度，我们最近进行了具有端粒长度的全基因组CRISPR/Cas9筛查 读数。除了识别已知的端粒维持基因外，我们还发现了端粒维持基因与端粒维持基因之间的关联 几个核苷酸代谢基因和端粒长度。最新的人类基因组全关联研究 也连接了核苷酸代谢基因和血细胞中的端粒长度。初步实验 在我们实验室进行的研究表明，核苷酸的遗传和小分子扰动 新陈代谢可以迅速而有力地改变人类细胞的端粒长度，包括诱导的多能干细胞 来自TBDS患者的细胞。然而，在这两个机制中都存在基本的知识空白 这一效应的基础，以及操纵核苷酸代谢是否可以改变端粒的维持 造血系统，这可能在治疗上有用。在这里，我们的目标是揭示核苷酸是如何 代谢紊乱改变了人类细胞的端粒长度，包括体外和体内的人类模型 造血术。这项研究包括两个目的：(1)如何改变核苷酸代谢基因 影响端粒维持，以及(2)核苷酸代谢的小分子操作如何改变 端粒稳态，在人类细胞中，包括原代造血干细胞和祖细胞。对于此F30 获奖后，PI设计了一个研究战略和培训计划，将为他提供：(1)基础 代谢组学、生物信息学和端粒生物学方面的专业知识，(2)一个由导师和 合作者不仅促进研究专业知识，而且还促进职业生涯的学术技能，包括 专业精神和科学交流，以及(3)从事以翻译为主的血液学的经验 为他作为内科科学家的职业目标做准备的研究。这项提议将发生在富人和 哈佛医学院和波士顿儿童医院的合作研究环境。完成这项工作 这项工作有望将核苷酸代谢确立为人类端粒稳态的关键调节因素， 包括骨髓在内的高度未满足需求的血液系统疾病的治疗意义 衰竭和再生障碍性贫血，以及其他非造血退行性疾病。

PROJECT SUMMARY/ABSTRACT: Telomere homeostasis is critical for cellular replicative capacity and human health. Telomeres shorten with cellular replication and when critically short, trigger senescence and halt cell division. Inherited mutations in telomere maintenance genes are associated with severe hematopoietic disorders including childhood-onset bone marrow failure, aplastic anemia, and myelodysplastic syndrome, as well as non-hematopoietic conditions including liver cirrhosis and pulmonary fibrosis. These diseases are collectively referred to as telomere biology disorders (TBDs). Treatment for TBDs is centered on supportive care and bone marrow or organ transplant which often have poor outcomes and leave patients at risk for other disease manifestations. New approaches to therapeutically lengthen telomeres and treat TBDs are needed. In order to identify novel pathways controlling human telomere length, we recently performed a genome-wide CRISPR/Cas9 screen with a telomere length readout. In addition to identifying known telomere maintenance genes, we identified an association between several nucleotide metabolism genes and telomere length. Recent human genome wide association studies have also connected nucleotide metabolism genes and telomere length in blood cells. Preliminary experiments performed in our laboratory demonstrate that both genetic and small molecule perturbations of nucleotide metabolism can rapidly and robustly alter telomere length in human cells, including induced pluripotent stem cells derived from patients with TBDs. However, there are fundamental knowledge gaps both in the mechanisms underlying this effect, and whether manipulating nucleotide metabolism could alter telomere maintenance in the hematopoietic system, which could be therapeutically useful. Here, we aim to uncover how nucleotide metabolism perturbations alter telomere length in human cells, including in vitro and in vivo models of human hematopoiesis. This study consists of two aims to investigate: (1) how altering nucleotide metabolism genes impacts telomere maintenance, and (2) how small molecule manipulation of nucleotide metabolism alters telomere homeostasis, in human cells including primary hematopoietic stem and progenitor cells. For this F30 award, the PI has designed a research strategy and training program that will provide him with: (1) fundamental expertise in metabolomics, bioinformatics, and telomere biology, (2) an expert group of mentors and collaborators to promote not only research expertise, but also career-long academic skills including grantsmanship and scientific communication, and (3) experience performing translation-focused hematology research in preparation for his career goal as a physician-scientist. This proposal will take place in the rich and collaborative Harvard Medical School and Boston Children’s Hospital research environments. Completion of this work is expected to establish nucleotide metabolism as a critical regulator of human telomere homeostasis, with therapeutic implications for the treatment of hematopoietic diseases with high unmet need including bone marrow failure and aplastic anemia, as well as other non-hematopoietic degenerative diseases.