Investigation of the Tip60-p400 complex role in embryonic stem cell self-ren

Tip60-p400复合物在胚胎干细胞自体中作用的研究

• 批准号: 8034735
• 负责人: BARBARA PANNING
• 金额: $ 28.97万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8034735
• 关键词: ATP phosphohydrolase; Acetyltransferase; Adult; Affect; Applied Research; Binding; Cell Therapy; Cells; Chromatin; Chromatin Remodeling Factor; Chromatin Structure; Complex; DNA; DNA Binding; DNA-Binding Proteins; Data; Deacetylase; Deposition; Development; ES Cell Line; Exhibits; Frequencies; Future; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Targeting; Generic Drugs; Genes; Genetic Transcription; Hematopoietic stem cells; Histone H3; Histone H4; Histones; Homeodomain Proteins; In Vitro; Investigation; Lead; Lysine; Maintenance; Malignant Neoplasms; Mammalian Cell; Mediator of activation protein; Modeling; Molecular; Molecular Profiling; Mus; Nature; Organism; Pattern; Process; Proliferating; Property; Proteins; RNA Interference; RNA Polymerase II; Recruitment Activity; Regulation; Relative (related person); Role; Source; Specific qualifier value; Stem cells; Testing; Translating; Undifferentiated; Variant; cell type; chromatin modification; computerized data processing; embryonic stem cell; environmental change; established cell line; genetic regulatory protein; histone acetyltransferase; in vivo; pluripotency; programs; promoter; public health relevance; research study; response; self-renewal; stem cell population; stem cell technology; stem cell therapy; tool; transcription factor

DESCRIPTION (provided by applicant): Multicellular organisms consist of hundreds of different cell types, each of which is characterized by a unique pattern of gene expression. Different cell types must stably maintain the transcriptional patterns that specify that cell type, yet have sufficient plasticity to allow the alterations in gene expression that are necessary for differentiation or responses to environmental changes. Establishment and maintenance of these diverse expression patterns is fundamentally important for cell identity and organismal survival, since aberrant gene expression in a single cell can lead to developmental abnormalities or cancer. We use mouse embryonic stem cells (ESCs) to study the molecular mechanisms that are used to regulate gene expression in mammalian cells. ESCs are pluripotent, with the ability to differentiate into every cell type that makes up the developing and adult organism. ESCs continue to self-renew, or indefinitely proliferate in the pluripotent state, when they are cultured under appropriate conditions. Several transcription factors, such as Oct4, Nanog, Sox2, Foxd3, and Stat3, are essential for self-renewal and pluripotency. While it is thought that regulation at the level of chromatin structure is also important in ESC self-renewal and pluripotency, the role of chromatin regulatory proteins in these processes remains more poorly understood. Here we propose to investigate the role of the Tip60-p400 histone acetyltransferase-chromatin remodeling complex in ESC self-renewal. Our preliminary results indicate that tip60-p400 cooperates with the pluripotency transcription factor Nanog to maintain the ESC-specific expression profile that promotes self-renewal and pluripotency. Our studies will focus on understanding the molecular nature of the functional interaction between the Tip60-p400 complex and Nanog. Finally, our preliminary results implicate a second chromatin remodeling complex, the Brg1-containing Swi/Snf complex in ESC self-renewal. We will also investigate the mechanisms by which this complex regulates the ESC-specific gene expression profile. PUBLIC HEALTH RELEVANCE: Embryonic stem cells can grow indefinitely as an established cell line, a process referred to as self-renewal. ESCs are highly proliferative in their undifferentiated state. In contrast, somatic stem cells, such as hematopoietic stem cells, grow more slowly than ESCs and do not expand without significant accompanying differentiation. ESCs are also pluripotent - they have the ability to differentiate into all cell types. Because of these properties, ESCs are regarded as a major potential source of material for stem cell therapies. However, the molecular mechanisms governing self-renewal and pluripotency are largely unknown. A better molecular understanding at the factors that induce and maintain the stem cell state ESCs is essential for moving towards the implementation of ESC-based therapies. We employ mouse ESCs to understand the role of chromatin regulatory proteins, which regulate gene expression by affecting the accessibility of the DNA template, in ESC self-renewal and pluripotency. These studies will have important impacts on the development of ESC lines for stem-cell based therapies.

描述（由申请人提供）：多细胞生物体由数百种不同的细胞类型组成，每种细胞类型的特征在于独特的基因表达模式。不同的细胞类型必须稳定地维持指定该细胞类型的转录模式，但具有足够的可塑性以允许基因表达的改变，这是分化或对环境变化的反应所必需的。这些不同表达模式的建立和维持对于细胞身份和生物体存活至关重要，因为单个细胞中的异常基因表达可导致发育异常或癌症。我们使用小鼠胚胎干细胞（ESC）来研究用于调节哺乳动物细胞中基因表达的分子机制。ESC是多能的，具有分化成构成发育和成年生物体的每种细胞类型的能力。当在适当的条件下培养时，ESC继续自我更新，或以多能状态无限增殖。一些转录因子，如Oct 4，Nanog，Sox 2，Foxd 3和Stat 3，对于自我更新和多能性是必需的。虽然认为染色质结构水平的调节在ESC自我更新和多能性中也很重要，但染色质调节蛋白在这些过程中的作用仍然知之甚少。在这里，我们建议调查Tip 60-p400组蛋白乙酰转移酶-染色质重塑复合物在ESC自我更新中的作用。我们的初步结果表明，tip 60-p400与多能性转录因子Nanog合作，以维持促进自我更新和多能性的ESC特异性表达谱。我们的研究将集中在了解Tip 60-p400复合物和Nanog之间的功能相互作用的分子性质。最后，我们的初步研究结果暗示了第二个染色质重塑复合物，Brg 1含有Swi/Snf复合物在ESC自我更新。我们还将研究这种复合物调节ESC特异性基因表达谱的机制。 公共卫生相关性：胚胎干细胞可以作为已建立的细胞系无限生长，这一过程被称为自我更新。ESC在其未分化状态下高度增殖。相比之下，体干细胞，如造血干细胞，比ESC生长更慢，并且在没有显著伴随分化的情况下不会扩增。ESC也是多能的-它们具有分化成所有细胞类型的能力。由于这些特性，ESC被认为是干细胞治疗的主要潜在材料来源。然而，自我更新和多能性的分子机制在很大程度上是未知的。更好地理解诱导和维持干细胞状态ESC的因素对于实现基于ESC的治疗至关重要。我们采用小鼠胚胎干细胞来了解染色质调节蛋白的作用，它通过影响DNA模板的可及性来调节基因表达，在胚胎干细胞自我更新和多能性中。这些研究将对基于干细胞疗法的ESC系的开发产生重要影响。