Control of Telomere Homeostasis by Nucleotide Metabolism in Hematopoiesis

项目总结/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，并且当临界短时，触发衰老并停止细胞分裂。的遗传突变 端粒维持基因与严重的造血系统疾病有关， 骨髓衰竭、再生障碍性贫血和骨髓增生异常综合征，以及非造血系统疾病 包括肝硬化和肺纤维化。这些疾病统称为端粒生物学 疾病（TBD）。TBD的治疗以支持性护理和骨髓或器官移植为中心 其结果往往不佳，并使患者面临其他疾病表现的风险。的新办法 需要治疗性地延长端粒和治疗TBD。为了确定控制 人类端粒长度，我们最近进行了全基因组CRISPR/Cas9筛选与端粒长度 读数。除了确定已知的端粒维持基因，我们还确定了端粒与细胞凋亡之间的关联。 几个核苷酸代谢基因和端粒长度。最近的人类全基因组关联研究 还将血细胞中的核苷酸代谢基因和端粒长度联系起来。初步实验 在我们的实验室中进行的研究表明，核苷酸的遗传和小分子扰动 代谢可以快速和稳健地改变人类细胞中的端粒长度，包括诱导多能干细胞， 来自TBD患者的细胞。然而，在这两种机制方面都存在着根本性的知识差距， 这种效应的基础，以及操纵核苷酸代谢是否可以改变端粒的维持， 造血系统，这可能是治疗上有用的。在这里，我们的目标是揭示核苷酸 代谢扰动改变人细胞中的端粒长度，包括人细胞的体外和体内模型， 造血本研究主要包括两个方面：（1）改变核苷酸代谢基因 影响端粒的维持，以及（2）核苷酸代谢的小分子操作如何改变 端粒稳态，包括原代造血干细胞和祖细胞。关于F30 奖，PI设计了一个研究策略和培训计划，将为他提供：（1）基本的 代谢组学、生物信息学和端粒生物学方面的专业知识，（2）导师专家组， 合作者不仅要促进研究专业知识，还要促进职业生涯的学术技能，包括 医学和科学交流，以及（3）执行以预防为重点的血液学的经验 为实现他作为一名物理学家兼科学家的职业目标而进行的研究。这项提案将在富人和 合作哈佛医学院和波士顿儿童医院的研究环境。完成本 工作预期建立核苷酸代谢作为人类端粒稳态的关键调节器， 对治疗具有高度未满足需求的造血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系统变性疾病。

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.