Directing epigenetic maintenance in normal and malignant haematopoietic stem cells

背景：干细胞群体的建立和维持以及单个干细胞克隆如何“竞争”的过程是理解衰老和癌症的关键组成部分。在许多组织中的开创性发现极大地加深了我们对退行性疾病，特别是癌症生物学的理解。最近，在血液系统中，与年龄相关的克隆性造血在其他健康个体中的高流行率表明，克隆竞争中的异常可能是早期疾病发展的关键指标。这些突变大多发生在表观遗传修饰物(如TET2、DNMT3a、ASXL1)中，这些修饰物已被进一步证明直接调控血液干细胞的增殖。最近，我们发现一种名为CIZ1的蛋白质会影响至少三种不同的组蛋白修饰的稳定性，这样当CIZ1不能在细胞核内形成大的组装时，它们就会被耗尽。我们认为，这些组装通常会在选定的基因及其组蛋白周围形成一层屏障，以保护它们免受移除修饰的酶的影响。目的：确定CIZ1在原发HSC中的作用了解干扰CIZ1诱导的屏蔽完整性是否会破坏恶性肿瘤小鼠模型中细胞的稳定新颖和时间我们对Cip1相互作用的锌指蛋白1(CIZ1)的分析揭示了在高保真维持表观遗传格局中意想不到的作用，这似乎有助于避免疾病。来自转基因小鼠的空细胞仍然活着，但容易变得不稳定，而空动物容易患上血液系统恶性肿瘤。作为恶性血液病的始发细胞，尚未对原发造血干细胞进行任何研究，该项目将结合CIZ1的专业知识和宿主实验室的HSC生物学专业知识。这两个实验室目前都是由MRC资助的相关项目，这些项目将加速这个学生项目的影响。实验方法：该项目将涉及用于分离和表征血细胞群体的流式细胞术、单细胞RNA测序、单细胞ATAC测序和功能移植分析。这些技术将导致对CIZ1缺陷的HSCs及其对造血和疾病发展的影响的全面的分子和细胞理解。

Background: The process by which stem cell populations are established and maintained and how individual stem cell clones "compete" is a key component to understanding ageing and cancer. Seminal discoveries in a number of tissues have greatly informed our understanding of degenerative diseases and cancer biology in particular. More recently in the blood system, the high prevalence of age-related clonal haematopoiesis in otherwise healthy individuals has demonstrated that aberrations in clonal competition can be a key indicator of early disease development. Most of these mutations are in epigenetic modifiers (e.g., TET2, DNMT3a, ASXL1) which have further been shown to directly regulate proliferation in blood stem cells. Recently we showed that a protein called CIZ1 influences the stability of at least three different histone modifications, such that they are depleted when CIZ1 is not able to form large assemblies inside the nucleus of cells. We think that these assemblies normally form a shield around selected genes and their histones, to protect them from the enzymes that remove the modifications. Objectives:Establish the role of CIZ1 in primary HSCsUnderstand whether interference with CIZ1 induced shield integrity can destabilize cells in mouse models of malignancyNovelty and TimelinessOur analysis of Cip1-interacting Zinc finger protein 1 (CIZ1) has revealed an unexpected role in high-fidelity maintenance of epigenetic landscape, which appears to contribute to disease avoidance. Null cells derived from genetically modified mice remain viable yet prone to instability, while null animals are prone to haematological malignancies. Nothing has been investigated in primary HSCs, the initiating cells of haematological malignancies and this project will combine CIZ1 expertise and HSC biology expertise in the host laboratories. Both labs are currently MRC-funded for related projects that will accelerate the impact of this student project.Experimental Approach:The project will involve flow cytometry for isolating and characterising blood cell populations, single cell RNA-sequencing, single cell ATAC-sequencing and functional transplantation assays. These techniques will lead to a comprehensive molecular and cellular understanding of CIZ1-deficient HSCs and its impact on haematopoiesis and disease development.