Structure of post-replicative chromatin during cell reprogramming in fibrotic disease

纤维化疾病细胞重编程过程中复制后染色质的结构

• 批准号: 9895805
• 负责人: ALEXANDER M MAZO
• 金额: $ 37.75万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9895805
• 关键词: Address; Affect; Belief; Binding; Biological Models; Biological Process; Blindness; Cataract Extraction; Cell Cycle Stage; Cell Differentiation process; Cell Proliferation; Cell model; Cells; Chromatin; Chromatin Structure; Cicatrix; Complex; DNA; DNA biosynthesis; Data; Daughter; Disease; Disease Progression; Environment; Enzymes; Epigenetic Process; Epithelial; Epithelium; Eukaryota; Event; Exposure to; Extracellular Matrix; Eye; Eye diseases; Fibrosis; Genetic Transcription; Growth Factor Receptors; Heritability; Histones; Human; Injury; Knowledge; MADH4 gene; Mediating; Mediator of activation protein; Mesenchymal; Methods; Modeling; Molecular; Mus; Myofibroblast; Nature; Nucleosomes; Operative Surgical Procedures; Organ; Outcome; Pathologic; Phenotype; Process; Property; Proteins; Receptor Signaling; Site; Smooth Muscle Actin Staining Method; Source; Structure; Testing; Therapeutic; Time; Tissues; Transforming Growth Factor beta; base; capsule; cell type; epigenetic memory; epigenetic regulation; eye center; genome-wide; histone modification; lens; preservation; prevent; programs; recruit; stem cells; therapeutic target; tool; transcription factor; Address; Affect; Belief; Binding; Biological Models; Biological Process; Blindness; Cataract Extraction; Cell Cycle Stage; Cell Differentiation process; Cell Proliferation; Cell model; Cells; Chromatin; Chromatin Structure; Cicatrix; Complex; DNA; DNA biosynthesis; Data; Daughter; Disease; Disease Progression; Environment; Enzymes; Epigenetic Process; Epithelial; Epithelium; Eukaryota; Event; Exposure to; Extracellular Matrix; Eye; Eye diseases; Fibrosis; Genetic Transcription; Growth Factor Receptors; Heritability; Histones; Human; Injury; Knowledge; MADH4 gene; Mediating; Mediator of activation protein; Mesenchymal; Methods; Modeling; Molecular; Mus; Myofibroblast; Nature; Nucleosomes; Operative Surgical Procedures; Organ; Outcome; Pathologic; Phenotype; Process; Property; Proteins; Receptor Signaling; Site; Smooth Muscle Actin Staining Method; Source; Structure; Testing; Therapeutic; Time; Tissues; Transforming Growth Factor beta; base; capsule; cell type; epigenetic memory; epigenetic regulation; eye center; genome-wide; histone modification; lens; preservation; prevent; programs; recruit; stem cells; therapeutic target; tool; transcription factor

Project Summary: Most tissues of the eye are susceptible to developing fibrotic disease, blinding millions of people throughout the world. There are no effective approaches to prevent, slow or reverse this disease process. The cell type responsible for causing fibrotic disease is the myofibroblast. Understanding how a cell acquires an altered heritable phenotype to become a myofibroblast, leading to scarring associated with this pathological disease process, is a key question, likely to provide essential clues toward developing anti-fibrotic therapeutics. Changing transcriptional programming during reprogramming of a cell to a myofibroblast is not well understood. In many aspects, it may rely on changes in the epigenetic mechanisms of inheritance of chromatin structure during DNA replication. The mechanism of epigenetic inheritance during cell proliferation remains unknown, and we know even less about how epigenetic information and the corresponding transcriptional programs change during cell reprogramming. The gaps in our knowledge of these essential biological processes are based on the lack of direct experimental approaches that would allow examining the structure of chromatin and the state of transcription during and following DNA replication during cell proliferation and cell differentiation. Using newly developed experimental paradigms, we found that epigenetic marking during cell proliferation relies not on the transfer of modified histones to daughter strands, but rather on stable association of multiple histone-modifying proteins during DNA replication. Similar results were obtained in multiple lens models of cell reprogramming leading to fibrotic disease. Lens cells before injury and until the first day following surgery in the ex vivo chick model have chromatin that is characterized by a significant delay in the accumulation of the key repressive histone mark H3K27me3 following DNA replication. This signifies a de-condensed structure of nucleosomes. The same `open' post-replicative chromatin was also discovered in mouse and human lens cells during their induction to the myofibroblast phenotype, suggesting that this is a previously unknown pivotal property of all myofibroblast progenitor cells. Our data suggests that this `open' state of post-replicative chromatin is more amenable to binding of newly induced specific transcription factors (TFs) essential for cell reprogramming. Importantly, the state of `open' chromatin may be manipulated in order to change the ability of TFs to associate with their target sites on DNA to therapeutically target myofibroblast differentiation. We propose to further examine: 1) The epigenetic mechanisms involved in regulating cell reprogramming to a myofibroblast and 2) Whether epigenetic mechanisms can be manipulated to alter phenotypic outcome of cell reprogramming to a myofibroblast. We anticipate that the epigenetic molecular events and anti-fibrotic strategies discovered from the proposed studies will apply to treating fibrosis in the eye and most tissue types.

项目摘要：大多数眼睛的组织都容易患纤维化疾病，盲目 全世界数百万人。没有有效的方法可以预防，缓慢或反向 这个疾病过程。负责引起纤维化疾病的细胞类型是肌纤维细胞。 了解细胞如何获得变化的可遗传表型成为肌纤维细胞，从而导致 与这种病理疾病过程相关的疤痕是一个关键问题，可能会提供必不可少的 发展抗纤维化治疗剂的线索。更改转录编程期间 将细胞重新编程为肌纤维细胞尚不清楚。在许多方面，它可能依靠 DNA复制过程中染色质结构遗传的表观遗传机理的变化。这 细胞增殖过程中表观遗传遗传的机制仍然未知，我们知道的较少 关于在细胞期间的表观遗传信息和相应的转录程序的变化 重新编程。我们了解这些基本生物过程的差距是基于 缺乏直接的实验方法，可以检查染色质的结构和 在细胞增殖和细胞分化过程中DNA复制期间和之后的转录状态。 使用新开发的实验范式，我们发现细胞中的表观遗传标记 扩散不依赖于修饰的组蛋白转移到女儿链，而是依赖于稳定的 在DNA复制过程中，多种组蛋白修饰蛋白的缔合。获得了类似的结果 在多种细胞重编程的镜头模型中，导致纤维化疾病。受伤前的镜头细胞，直到 手术后的第一天，在体内小鸡模型中的染色质，其特征是 DNA之后，钥匙抑制组蛋白标记H3K27me3的积累显着延迟 复制。这表示核小体的解凝结结构。相同的“开放”后复制 染色质在小鼠和人透镜细胞诱导过程中也发现了染色质 表型，表明这是所有肌纤维细胞祖细胞的先前未知的关键特性 细胞。我们的数据表明，这种复制后染色质的“开放”状态更适合约束 新诱导的特定转录因子（TFS）对于细胞重编程所必需的。重要的是， 可以操纵“开放”染色质状态，以改变TF与其关联的能力 DNA上的靶位点以治疗靶向肌纤维细胞分化。我们建议进一步检查： 1）调节细胞重编程为肌纤维细胞的表观遗传机制和2） 是否可以操纵表观遗传机制来改变细胞重编程的表型结果 到肌纤维细胞。我们预计表观遗传分子事件和抗纤维化策略 从拟议的研究中发现的将适用于眼睛和大多数组织类型的纤维化。