Epigenetic mechanisms of gene regulation in nephron progenitor cell proliferation and differentiation

肾单位祖细胞增殖和分化基因调控的表观遗传机制

基本信息

批准号：
10672271
负责人：
MICHAEL I RAUCHMAN
金额：
$ 42.03万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10672271
关键词：
Acceleration Address Adult Affect Area Back Binding Cell Differentiation process Cell Lineage Cell Separation Cells Childhood Chromatin Chromatin Remodeling Factor Chronic Kidney Failure Complement Complex Congenital Abnormality Cues Deacetylase Defect Development Disease Distal Embryo Endowment Enhancers Epigenetic Process Epithelial Cells Equilibrium Event Functional disorder Gene Expression Gene Expression Profile Gene Expression Regulation Genes Genetic Genome Genomics Goals Henle&apos s loop Human Human Development Human Genetics Hypertension Impairment Individual Injury Kidney Kidney Diseases Kidney Failure Knock-in Mouse Knowledge Life LoxP-flanked allele Methods Modification Molecular Mus Natural regeneration Nephrons Nucleic Acid Regulatory Sequences Nucleosomes Organ Pattern Formation Physiological Play Polycomb Population Premature Birth Premature Infant Proliferating Proteins Regulation Regulatory Element Renal function Renal glomerular disease Research Role Signal Pathway Signal Transduction Sodium Chloride Sucrose Syndrome Testing Time Tissues Translating Tubular formation Undifferentiated WNT Signaling Pathway Water Work cell type conditional mutant end-stage organ failure epigenome editing exhaustion gene regulatory network genome-wide human disease induced pluripotent stem cell inhibitor insight kidney cell mutant nephrogenesis nephron progenitor novel predictive modeling progenitor programs promoter renal epithelium repaired self-renewal stem cell growth stem cell proliferation stem cells transcription factor

项目摘要

The long-term goal of the proposed work is to determine mechanisms that control gene regulatory networks to generate a normal endowment of mature nephrons. Formation of the proper complement of nephrons requires a balance between self-renewal and differentiation of progenitor cells. Disruption of this balance leads to renal hypoplasia and chronic kidney disease. Soon after progenitor cells begin to differentiate, chromatin must undergo significant changes to set up gene expression patterns for formation of distinct cell types along the nephron. Defects in formation of specific renal epithelial cell types leads to glomerular disease and an inability of tubules to perform normal physiological functions, such as maintaining salt and water balance. A major mechanism by which cells respond to signals to direct gene expression to a particular fate or lineage is through the concerted action of chromatin remodeling complexes and tissue restricted transcription factors. These proteins act on regulatory regions in the genome to establish control of gene expression at the correct time and place. While individual factors that control gene expression in nephron progenitor cells have been defined, how these proteins cooperate to control gene expression in the developing kidney has not been explored. The identification and characterization of the regulatory elements where these factors act is also a major challenge in the field. We discovered that Sall1 plays a pivotal role in these developmental decisions by interacting with two distinct chromatin remodeling complexes, the Nucleosome Remodeling and Deacetylase (NuRD) complex and the Switch/Sucrose Non-Fermentable (SWI/SNF) complex. We propose that the integrated actions of Sall1, Six2, NuRD and SWI/SNF controls nephron progenitor cell gene expression to attain a dynamic balance between self-renewal and differentiation, and establishes the epigenetic modifications required for formation of specific cell lineages in the mature kidney. This novel paradigm will be tested in three Aims. In Aim 1, we will perform Hi-ChIP to identify enhancer-promoter contacts in uncommitted and induced progenitors, and define changes in mutant cells. Aim 2 will determine how genomic binding of Sall1, Six2, NuRD and SWI/SNF are affected in mutant nephron progenitor cells. Epigenomic editing will be used to demonstrate causal relationships between gene expression and binding of these factors at regulatory regions. In order to translate our findings to human development and disease, in Aim 3 we will test our findings in the mouse from Aims 1 and 2 in human iPS cell-derived nephron progenitor cells. These studies will illuminate mechanisms that underlie human genetic syndromes and sporadic birth defects, such as renal hypoplasia, which commonly cause childhood kidney failure. Our findings will also provide insight into how to reprogram kidney cells from a differentiated state back to a progenitor state, to promote regeneration of mature tubular epithelial cells in order to correct nephron deficits.

拟议工作的长期目标是确定控制基因调控网络的机制产生成熟肾单位的正常禀赋。形成适当的肾单位补充需要祖细胞的自我更新和分化之间的平衡。这种平衡的破坏会导致肾发育不全和慢性肾脏疾病。祖细胞开始分化后不久，染色质必须经历重大改变才能建立基因表达模式，从而形成不同的细胞类型肾单位。特定肾上皮细胞类型的形成缺陷会导致肾小球疾病和肾小球疾病肾小管无法执行正常的生理功能，例如维持盐和水的平衡。细胞响应信号以引导基因表达达到特定命运或目标的主要机制谱系是通过染色质重塑复合物和组织限制性转录的协同作用实现的因素。这些蛋白质作用于基因组中的调节区域，以建立对基因表达的控制正确的时间和地点。虽然控制肾单位祖细胞基因表达的个体因素已被定义，但这些蛋白质如何合作控制发育中肾脏的基因表达尚未明确探索过。这些因素发挥作用的监管要素的识别和特征也是一个该领域的重大挑战。我们发现 Sall1 通过与两个细胞相互作用，在这些发育决策中发挥着关键作用。不同的染色质重塑复合物、核小体重塑和脱乙酰酶 (NuRD) 复合物以及 Switch/蔗糖不可发酵 (SWI/SNF) 复合物。我们建议 Sall1 的综合行动， Six2、NuRD和SWI/SNF控制肾单位祖细胞基因表达达到动态平衡自我更新和分化之间，并建立形成所需的表观遗传修饰成熟肾脏中的特定细胞谱系。这种新颖的范式将在三个目标中进行测试。在目标 1 中，我们将执行 Hi-ChIP 来识别未定型和诱导祖细胞中的增强子-启动子接触，并定义突变细胞的变化。目标 2 将确定 Sall1、Six2、NuRD 和 SWI/SNF 的基因组结合方式突变肾单位祖细胞受到影响。表观基因组编辑将用于证明因果关系基因表达与这些因子在调控区域的结合之间的关系。为了翻译我们的发现对人类发育和疾病的影响，在目标 3 中，我们将在目标 1 的小鼠中测试我们的发现 2 个来自人 iPS 细胞衍生的肾单位祖细胞。这些研究将阐明人类遗传综合症和零星出生的机制缺陷，例如肾发育不全，通常会导致儿童肾衰竭。我们的研究结果还将深入了解如何将肾细胞从分化状态重新编程回祖细胞状态，以促进成熟肾小管上皮细胞的再生，以纠正肾单位缺陷。