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

• 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
• 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' 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

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.

这项拟议工作的长期目标是确定控制基因调控网络的机制。 才能产生正常的成熟肾细胞。肾单位的适当补语的形成 需要在自我更新和祖细胞分化之间取得平衡。破坏这种平衡会导致 肾发育不全和慢性肾脏疾病。在祖细胞开始分化后不久，染色质 必须经历显著的变化来建立基因表达模式，以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 肾小管不能执行正常的生理功能，如维持盐和水的平衡。 细胞对信号作出反应的一种主要机制，将基因表达引导到特定的命运或 血统是通过染色质重塑复合体和组织限制性转录的协同作用实现的。 各种因素。这些蛋白质作用于基因组中的调节区，以在 正确的时间和地点。而控制肾单位祖细胞基因表达的个别因素 这些蛋白质如何在发育中的肾脏中协同控制基因表达还没有被定义。 探索过了。对这些因素起作用的调控因素的识别和表征也是一个 该领域的重大挑战。 我们发现，SALL1通过与两个基因相互作用，在这些发育决定中起着关键作用 不同的染色质重塑复合体，核小体重塑和脱乙酰酶(NuRD)复合体和 开关/蔗糖不可发酵(SWI/SNF)复合体。我们建议Sall1的综合行动， SIX2、NuRD和SWI/SNF调控肾小球祖细胞基因表达达到动态平衡 在自我更新和分化之间，并建立了形成 成熟肾脏中的特定细胞谱系。这一新的范式将在三个目标上进行测试。在目标1中，我们将 进行Hi-ChIP以确定未承诺和诱导的祖细胞中的增强子-启动子接触，并定义 突变细胞的变化。AIM 2将确定SALL1、SIX2、NuRD和SWI/SNF的基因组结合情况 在突变的肾单位祖细胞中受到影响。表观基因组编辑将被用来证明因果关系 基因表达与这些因子在调控区域结合的关系。为了翻译 我们的发现与人类发育和疾病有关，在目标3中，我们将在AIMS 1的小鼠身上测试我们的发现 2在人iPS细胞来源的肾小球祖细胞中。 这些研究将阐明人类遗传综合征和零星出生的机制。 缺陷，如肾发育不全，通常会导致儿童肾衰竭。我们的发现也将 提供有关如何将肾细胞从分化状态重新编程回祖细胞状态的见解，以 促进成熟肾小管上皮细胞再生，以纠正肾单位缺陷。