Defining the molecular basis controlling hematopoietic stem cell symmetric and asymmetric divisions

项目总结和摘要 造血干细胞（HSC）通过对造血干细胞命运选择的微妙平衡来维持血液稳态。 自我更新和致力于差异化。HSC命运选择的不平衡是 影响数百万人的血液病HSC的命运选择是由协调对称的 自我更新、对称承诺和不对称分工。因此，了解HSC的控制 分裂选择对造血系统疾病具有治疗潜力。然而，我们对控制的了解 目前，尚缺乏HSC。在这里，我的目标是通过实现新颖的系统和高吞吐量来填补差距 询问HSC命运选择的测定。我们最近揭示了m6 A RNA甲基化的独特作用， 对HSC对称承诺至关重要，部门选择对快速补充至关重要， 成熟的血细胞因此，我建议利用m6 A缺陷的HSC作为一种新的系统， 阐明了控制HSC对称定型的m6 A相关分子程序。揭开 在HSC命运选择的新的监管机构，我的目的是定义的作用，研究的RBP NYNRIN，这是一个 从我的初步数据和我们最近的AML-iPSC研究中确定的控制HSC的干性因子， 分裂我的目标还包括实现FATE-seq，这是一种新的方法，涉及HSC条形码，然后在体外 分裂和单细胞RNAseq，允许对HSC分裂进行全面评估。FATE-seq作为 正交系统将确定HSC命运选择的新调节剂。具体目标是：（1）：特征化 由m6 A RNA甲基化控制的HSC样中间状态。(2)：确定分子程序 在控制HSC对称定型中由m6 A RNA甲基化驱动。(3)：发现新的监管机构 HSC对称和非对称命运决定。这项工作的成功将定义HSC的新型调节剂 命运控制并为血液病和干细胞扩增提供新的治疗机会。 博士Hanzhi Luo目前是Memorial Sloan分子药理学项目的博士后研究员 凯特林癌症中心她的初步成就包括揭示m6 A在HSC对称性中的作用。 承诺，以及用AML-iPSC模型揭示白血病干细胞中的RUNX 1依赖性。 这两项研究最近发表在Cell Reports上。她的长期目标是建立一个研究团队， 强调HSC命运选择的分子机制，并坚定地致力于翻译基本的 把新发现带到诊所。这项研究将为罗博士在造血方面提供新的培训， RNA调节剂。这项工作将在MSKCC进行，这是一个令人兴奋的研究环境， 边缘设施。罗博士将由研究RNA调节剂的领先专家Michael Kharas博士指导 正常和恶性干细胞的研究，以及年轻学员的忠实支持者。在一起，这个职业 发展计划将帮助罗博士在一个以研究为导向的学术机构建立她的独立研究实验室 成为造血领域的领导者。

PROJECT SUMMARY AND ABSTRACT Hematopoietic stem cells (HSCs) maintain blood homeostasis through a delicate balance in fate choices of self-renewal and commitment to differentiation. An imbalance in HSC fate choices is the key contributor to hematologic diseases that affect millions of people. HSC fate choices is maintained by coordinated symmetric self-renewal, symmetric commitment and asymmetric divisions. Thus, understanding the control of HSC division choices holds therapeutic potential for hematopoietic diseases. However, our knowledge on the control of HSC divisions is still lacking. Here, I aim to fill the gap by implementing novel systems and high-throughput assays to interrogate HSC fate choices. We recently revealed a unique role of m6A RNA methylation that is essential for HSC symmetric commitment, the division choice that is critical for the rapid replenishment of mature blood cells upon stress. Hence, I propose to leverage the m6A deficient HSCs as a novel system to elucidate the m6A-associated molecular programs in controlling HSC symmetric commitment. To uncover novel regulators in HSC fate choices, I aim to define the role of the understudied RBP NYNRIN, which is a stemness factor identified from my preliminary data and our recent AML-iPSC study, in controlling HSC divisions. I also aim to implement FATE-seq, a novel method involves HSC barcoding followed by in vitro division and single cell RNAseq that allows for a global assessment of HSC divisions. FATE-seq as an orthogonal system will identify novel regulators of HSC fate choices. The Specific Aims are: (1): Characterize the HSC-like intermediate state controlled by m6A RNA methylation. (2): Determine the molecular programs driven by m6A RNA methylation in controlling HSC symmetric commitment. (3): Uncover novel regulators in HSC symmetric and asymmetric fate decisions. Success of this work will define the novel regulators of HSC fate control and provide novel therapeutic opportunities for hematological diseases and stem cell expansion. Dr. Hanzhi Luo is currently a postdoc fellow in the Molecular Pharmacology program at the Memorial Sloan Kettering Cancer Center. Her initial achievements include uncovering m6A's role in HSC symmetric commitment, as well as revealing the RUNX1 dependency in leukemia stem cells with the AML-iPSC model. Both studies were recently published in Cell Reports. Her long-term goal is to establish a research team with an emphasis on molecular mechanisms of HSC fate choices with a strong commitment to translate basic sdiscoveries into the clinic. The proposed research will provide new training for Dr. Luo in hematopoiesis and RNA regulators. This work will be performed at the MSKCC, an exciting research environment with cutting- edge facilities. Dr. Luo will be mentored by Dr. Michael Kharas, a leading expert in studying RNA regulators in normal and malignant stem cells, and a dedicated supporter for young trainees. Together, this career development plan will help Dr. Luo establish her independent research lab at a research-oriented academic institute and become a leader in the field of hematopoiesis.