Regulation of Nephron Progenitor Cell Self-Renewal and Differentiation

肾单位祖细胞自我更新和分化的调节

• 批准号: 8638282
• 负责人: MICHAEL I RAUCHMAN
• 金额: $ 32.95万
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-07 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8638282
• 关键词: Agonist; Binding; Binding Sites; Biochemical; Cell Differentiation process; Cells; ChIP-seq; Childhood; Chromatin Remodeling Factor; Chronic Kidney Failure; Complement; Complex; Congenital Abnormality; Deacetylase; Development; Differentiation Inhibitor; Elements; Embryo; End stage renal failure; Endowment; Enhancers; Ensure; Epigenetic Process; Epithelial; Epithelial Cells; Equilibrium; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Genetically Engineered Mouse; Genomics; Goals; Human; Human Genetics; Hypertension; In Vitro; Injury; Kidney; Kidney Diseases; Kidney Failure; Knock-in Mouse; Knowledge; Life; Maintenance; Maps; Mesenchyme; Messenger RNA; Modeling; Molecular; Mus; Mutant Strains Mice; Mutate; Natural regeneration; Nephrons; Nucleosomes; Organ; Organ Culture Techniques; Output; Patients; Play; Population; Regulation; Renal function; Research; Risk; Signal Transduction; Sorting - Cell Movement; Stem cells; Syndrome; Testing; Therapeutic; Transcriptional Regulation; Tubular formation; Undifferentiated; Ureter; Vesicle; Work; epithelial to mesenchymal transition; exhaustion; genome wide association study; in vivo; inhibitor/antagonist; insight; mutant; nephrogenesis; novel; precursor cell; premature; prevent; progenitor; public health relevance; repaired; research study; response; self-renewal; stemness; transcription factor

SUMMARY/ABSTRACT The long-term goal of the proposed work is to determine how the Sall1 transcription factor and its associated chromatin remodeling complexes control gene regulation to generate a normal endowment of nephrons. This will illuminate mechanisms that underlie human genetic syndromes and common sporadic birth defects, such as renal hypoplasia (small kidneys with reduced numbers of nephrons), which result in kidney failure. Formation of the proper complement of nephrons requires a balance between expansion of multi-potent renal progenitor cells and differentiation. Genetic deficiency of Sall1 alters gene expression in the developing kidney, accelerating nephron differentiation leading to a depletion of nephron progenitor cells and renal hypoplasia. These uncommitted nephron precursors, termed cap mesenchyme, must respond to canonical Wnt/ss-catenin signals by either undergoing self-renewal or mesenchymal-to-epithelial transition to form most tubular segments of the nephron. The transcriptional mechanisms that control these opposing responses of the cap mesenchyme are not known, but current evidence argues that Sall1 is pivotal in this critical developmental decision. Our recent studies provide evidence for a novel paradigm. We propose that Sall1 cooperates with the Nucleosome Remodeling and Deacetylase (NuRD) chromatin remodeling complex, to determine nephron progenitor cell fate by regulating the transcriptional output in response to Wnt/ss-catenin. This application will test key predictions of this model using a combination of genetic, genomic, and biochemical approaches. Six2 is an inhibitor of nephron differentiation. In Aim 1, we will determine if Sall1 directly up-regulates Six2 expression in cap mesenchyme to restrain differentiation of progenitor cells. Expression of Wnt9b, the main differentiation signal, is increased in Sall1 mutants. We will determine if the combination of increased Wnt9b and reduced Six2 expression are sufficient to cause accelerated nephron formation, and exhaustion of self-renewing progenitor cells. Aim 2 will determine how Sall1 and NuRD control the transcriptional output in nephron progenitor cells to determine whether the uncommitted precursor cells undergo self-renewal or initiate nephron differentiation. The mechanistic insights gained from these studies will advance efforts to propagate nephron progenitors in vitro and/or promote regeneration of mature tubular epithelial cells in order to correct nephron deficits.

摘要/摘要 这项工作的长期目标是确定 Sall1 转录因子及其 相关的染色质重塑复合物控制基因调控以产生正常的染色质赋予 肾单位。这将阐明人类遗传综合症和常见零星出生的机制 缺陷，例如肾发育不全（肾小，肾单位数量减少），导致肾 失败。 肾单位的适当补充的形成需要多能扩张之间的平衡 肾祖细胞和分化。 Sall1 的遗传缺陷改变了发育中的基因表达 肾脏，加速肾单位分化，导致肾单位祖细胞和肾脏的耗竭 发育不全。这些未承诺的肾单位前体，称为帽间充质，必须对规范做出反应 Wnt/ss-连环蛋白信号通过自我更新或间充质到上皮的转变形成大多数 肾单位的管状部分。控制这些相反反应的转录机制 帽间充质尚不清楚，但目前的证据表明 Sall1 在这一关键发育过程中至关重要 决定。 我们最近的研究为一种新颖的范式提供了证据。我们建议 Sall1 与 核小体重塑和脱乙酰酶 (NuRD) 染色质重塑复合物，以确定肾单位 通过响应 Wnt/ss-catenin 调节转录输出来调节祖细胞的命运。 该应用程序将结合遗传、基因组和基因组学来测试该模型的关键预测。 生化方法。 Six2 是肾单位分化的抑制剂。在目标 1 中，我们将确定 Sall1 是否 直接上调帽间充质中 Six2 的表达以抑制祖细胞的分化。 Wnt9b（主要分化信号）的表达在 Sall1 突变体中增加。我们将确定是否 Wnt9b 增加和 Six2 表达减少的组合足以导致肾单位加速 自我更新祖细胞的形成和耗尽。目标 2 将确定 Sall1 和 NuRD 如何控制 肾单位祖细胞中的转录输出以确定未定型前体细胞是否 进行自我更新或启动肾单位分化。从这些研究中获得的机制见解将 推进体外繁殖肾单位祖细胞和/或促进成熟肾小管再生的努力 上皮细胞以纠正肾单位缺陷。