Wnt/Beta-catenin and Tcf/Lef factor regulation of pluripotency

Wnt/β-连环蛋白和 Tcf/Lef 因子对多能性的调节

• 批准号: 8775490
• 负责人: Bradley J Merrill
• 金额: $ 32.03万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8775490
• 关键词: Address; Adult; Affect; Automobile Driving; Back; Beryllium; Binding; Binding Sites; Cardiac; Cell Differentiation process; Cell Therapy; Cell model; Cells; Characteristics; Clustered Regularly Interspaced Short Palindromic Repeats; Commit; DNA Binding; Data; Defect; Development; Developmental Biology; Elements; Embryo; Embryonic Development; Enhancers; Epigenetic Process; Exhibits; Formaldehyde; Foundations; Gene Expression; Genes; Genome; Genomics; Goals; Health; In Vitro; Indium; Knowledge; Maintenance; Maps; Measures; Molecular Biology; Mus; Oncogenic; Outcome; Phase; Physiological; Process; Property; Proteins; Protocols documentation; Regenerative Medicine; Regulation; Regulatory Element; Research; Role; Safety; Signal Transduction; Site; Specific qualifier value; Staging; Stem cells; Testing; Therapeutic; Work; base; beta catenin; cell type; drug development; embryonic stem cell; extracellular; gastrulation; human disease; in vivo; insight; mutant; pluripotency; relating to nervous system; response; self-renewal; stem; stem cell biology; stem cell fate; transcription factor

DESCRIPTION (provided by applicant): Previous groundbreaking discoveries have made it possible to grow pluripotent embryonic stem (ES) cells in vitro and to reprogram adult cells back to a pluripotent state. These advances have opened new opportunities for regenerative medicine by providing the cellular starting point from which we can derive adult cell types with physiological properties to study and treat human disease. Attaining cell types suitable for direct therapeutic application or as cellular models of human disease for drug development both require a substantial level of similarly to the in vivo cellular counterpart. Most often, investigaors attempt to attain the best in vivo mimics by replicating key aspects of a cell's developmental progression through embryogenesis. Given the appreciation that epigenetic effects are cumulative and progressive through embryogenesis, a central hypothesis of this proposal is that the initial steps in lineage specification are critical, and epigenetic mistakes made during exit from pluripotency can have undesirable effects even after cells have reached the targeted differentiated state. To address this problem, we aim to elucidate the mechanisms that eliminate or "decommission" ES cell- specific gene regulatory elements (i.e. enhancers) from lineage specified cell types. We discovered that a sequence-specific DNA-binding transcription factor, Tcf7l1, binds specifically to enhancers in ES cells that are targeted for decommissioning. Given our previous findings that showed Tcf7l1 stimulated differentiation of ES cells, we propose testing the hypothesis that Tcf7l1 is necessary to decommission ES specific enhancers. The proposal will further determine how this effect of Tcf7l1 changes the responses of cells to extracellular signals, and measure how important it is for genuine lineage specification using established in vitro differentiation protocols. The immediate outcome of completing the proposed research will be a better understanding of how cells exit the pluripotent state, and a demonstration of how defects during early steps can diminish the efficiency of subsequent stages of differentiation. Finally, given the oncogenic potential of accessible ES- specific enhancers in adult cells, the importance of the proposed work for increasing the safety of cell-based therapies should be appreciated.

描述（由申请人提供）：先前的突破性发现使得在体外培养多能胚胎干（ES）细胞并将成体细胞重新编程回多能状态成为可能。这些进展为再生医学开辟了新的机遇，为我们提供了细胞起点，我们可以从中衍生出具有生理特性的成体细胞类型来研究和治疗人类疾病。获得适合直接使用的细胞类型 治疗应用或作为用于药物开发的人类疾病的细胞模型都需要与体内细胞对应物具有相当高水平的相似性。大多数情况下，研究人员试图通过复制胚胎发生过程中细胞发育进程的关键方面来获得最佳的体内模拟。考虑到表观遗传效应在胚胎发生过程中是累积和渐进的，该提议的一个中心假设是，谱系规范的初始步骤至关重要，即使在细胞达到目标分化状态后，退出多能性期间发生的表观遗传错误也可能产生不良影响。为了解决这个问题，我们的目标是阐明从谱系特定细胞类型中消除或“停用”ES细胞特异性基因调控元件（即增强子）的机制。我们发现序列特异性 DNA 结合转录因子 Tcf7l1 与 ES 细胞中的增强子特异性结合，而 ES 细胞中的增强子是针对退役的。鉴于我们之前的研究结果表明 Tcf7l1 刺激 ES 细胞的分化，我们建议测试 Tcf7l1 对于停用 ES 特异性增强子所必需的假设。该提案将进一步确定 Tcf7l1 的这种作用如何改变细胞对细胞外信号的反应，并使用已建立的体外分化方案测量它对于真正的谱系规范的重要性。完成拟议研究的直接结果将是更好地了解细胞如何退出多能状态，并证明早期步骤中的缺陷如何降低后续分化阶段的效率。最后，考虑到成体细胞中可利用的 ES 特异性增强剂的致癌潜力，应该认识到所提出的提高细胞疗法安全性的工作的重要性。