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

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.

项目概述：眼睛的大多数组织容易发生纤维化疾病，致盲 全世界数以百万计的人。没有有效的方法来防止、减缓或扭转 这个疾病过程。导致纤维化疾病的细胞类型是肌成纤维细胞。 了解细胞如何获得改变的遗传表型成为肌成纤维细胞，从而导致 与这种病理性疾病过程相关的瘢痕形成是一个关键问题，可能提供必要的 开发抗纤维化疗法的线索。改变转录编程 将细胞重编程为肌成纤维细胞还没有被很好地理解。在许多方面，它可能依赖于 DNA复制过程中染色质结构遗传的表观遗传机制的变化。的 细胞增殖过程中的表观遗传机制仍不清楚，我们知道的更少 关于表观遗传信息和相应的转录程序如何在细胞内发生变化， 重新编程我们对这些基本生物过程的知识差距是基于 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期间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 增殖不依赖于修饰的组蛋白转移到子链，而是依赖于稳定的 DNA复制过程中多种组蛋白修饰蛋白的结合。获得了类似的结果 在导致纤维化疾病的细胞重编程的多个透镜模型中。损伤前和损伤后的透镜细胞 在离体鸡模型中，手术后第一天的染色质的特征在于： 在DNA扩增后，关键抑制性组蛋白标记H3K27me3的积累显著延迟， 复制的这表示核小体的解凝聚结构。同样的“开放”后复制 在小鼠和人透镜细胞诱导成肌成纤维细胞的过程中也发现了染色质 表型，这表明这是一个以前未知的关键性质，所有肌成纤维细胞祖细胞 细胞我们的数据表明，这种复制后染色质的“开放”状态更容易被结合， 新诱导的特异性转录因子（TF）对细胞重编程至关重要。重要的是 可以操纵“开放”染色质的状态，以改变TF与它们的细胞结合的能力。 靶向DNA上的位点以治疗性靶向肌成纤维细胞分化。我们建议进一步研究： 1)表观遗传机制参与调节细胞重编程为肌成纤维细胞和2） 表观遗传机制是否可以被操纵以改变细胞重编程的表型结果 转化成肌成纤维细胞我们预计，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治疗眼睛和大多数组织类型的纤维化。

项目成果

Immune cells in lens injury repair and fibrosis.

• DOI: 10.1016/j.exer.2021.108664
• 发表时间: 2021-08
• 期刊: Experimental eye research
• 影响因子: 3.4
• 作者: Walker JL;Menko AS
• 通讯作者: Menko AS

Resident immune cells of the avascular lens: Mediators of the injury and fibrotic response of the lens.

• DOI: 10.1096/fj.202002200r
• 发表时间: 2021-04
• 期刊: FASEB journal : official publication of the Federation of American Societies for Experimental Biology
• 作者: Menko AS;DeDreu J;Logan CM;Paulson H;Levin AV;Walker JL
• 通讯作者: Walker JL

The Pro-Fibrotic Response to Lens Injury Is Signaled in a PI3K Isoform-Specific Manner.

• DOI: 10.3390/biom12091181
• 发表时间: 2022-08-25
• 期刊: Biomolecules
• 影响因子: 5.5