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 拟议工作的长期目标是确定SALL1转录因子和它的 相关的染色质重塑复合体控制基因调控，以产生正常的 尼弗农。这将阐明人类遗传综合征和常见的零星出生的机制。 缺陷，如肾发育不全(肾小，肾单位数量减少)，导致肾脏 失败了。 肾单位的适当补语的形成需要在多项功能的扩展之间取得平衡 肾祖细胞与分化。SALL1基因缺陷改变发育过程中的基因表达 肾脏，加速肾单位分化，导致肾单位祖细胞和肾脏枯竭 发育不全。这些未确定的肾单位前体，称为帽间充质，必须对典型的 Wnt/ss-catenin信号通过自我更新或间质向上皮转化形成Most 肾单位的管状节。控制这些相反反应的转录机制 帽间充质蛋白尚不清楚，但目前的证据表明，SALL1在这一关键的发育过程中起着关键作用 决定。 我们最近的研究为一种新的范式提供了证据。我们建议SALL1与 核小体重塑与脱乙酰酶(NuRD)染色质重塑复合体测定肾单位 通过调节Wnt/ss-catenin的转录输出来调节祖细胞的命运。 此应用程序将使用遗传、基因组和 生化方法。SIX2是一种肾单位分化的抑制因子。在目标1中，我们将确定SALL1 直接上调帽间充质中SIX2的表达，以抑制祖细胞的分化。 SALL1突变体中主要分化信号Wnt9b的表达增加。我们将确定是否 Wnt9b增加和SIX2表达减少的组合足以引起加速的肾单位 自我更新的祖细胞的形成和耗尽。目标2将确定SALL1和NuRD如何控制 肾单位祖细胞转录输出量决定未定向祖细胞 进行自我更新或启动肾单位分化。从这些研究中获得的机械论见解将 体外扩增肾单位祖细胞和/或促进成熟肾小管再生的研究进展 以纠正肾单位缺乏症。