Exploring networks underlying muscle stem cell identity - Resubmission - 1

探索肌肉干细胞身份背后的网络 - 重新提交 - 1

基本信息

批准号：
10116803
负责人：
Brian D Dynlacht
金额：
$ 48.17万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10116803
关键词：
3-Dimensional Ablation Age Aging Architecture Binding Binding Sites Biochemical Cells Chimeric Proteins Chromatin Chromatin Loop Code Complex Data Disease Distal Elements Engraftment Enhancers Environment Epigenetic Process Exercise Exhibits Gene Expression Genes Genome Genomics Goals In Vitro Learning Light Modeling Molecular Mus Muscle Muscle Cells Muscle satellite cell Muscular Atrophy Mutation Myoblasts Myomatous neoplasm Natural regeneration Pathologic Play Population Process Property Proteins Proteomics Regenerative Medicine Regulator Genes Regulatory Element Resolution Rhabdomyosarcoma Role Scheme Shapes Site Specific qualifier value Structure System Transplantation base chromatin remodeling chromosome conformation capture embryonic stem cell epigenetic memory epigenome experimental study genome-wide analysis human embryonic stem cell in vivo insight interest mutant novel progenitor promoter recruit repaired satellite cell self-renewal stem stem cell fate specification stem cell function stem cell niche transcription factor wasting

项目摘要

Project Summary Muscle stem cells, also known as satellite cells (SC), are a progenitor population required to replenish muscle damaged by exercise or wasting caused by disease or aging. The ability to generate muscle progenitors from embryonic stem cells (ESC) would represent a major advance in regenerative medicine. However, despite recent progress, it remains very challenging to differentiate mouse and human ESC into muscle progenitors, and SC represent a very small population within muscle tissue. These limitations have significantly hampered progress toward understanding muscle stem cells, and the critical regulatory processes that govern SC identity. The transcription factor, Pax7, plays a critical role in establishing SC identity, but given the limitations associated with obtaining SC, our understanding of its molecular function remains incomplete. We have taken advantage of a system in which Pax7 expression in ESC generates myogenic precursors able to repopulate the SC niche, and we have begun investigating the chromatin landscape and epigenetic features of this population to understand its unique properties. With this system, we have shown that Pax7 can modulate enhancer function and genome topology. Our goal is to understand how a specific chromatin environment specifies satellite cell identity using state-of-the-art genomic, biochemical, and proteomic approaches. In two Aims, we will: (I) investigate how Pax7 re-models the genome, packaging chromatin for long-range interactions; (II) explore how Pax7 collaborates with other factors to establish gene expression and genome re-wiring in myogenic precursors in vitro and in vivo. We will inactivate a subset of Pax7-associated factors, enhancers, and identified regulatory elements and examine their functional impact on genome architecture, gene expression, cell identity, and differentiation. It is known that satellite cells are less efficiently renewed during aging, and given that muscle tumors (rhabdomyosarcomas) aberrantly express Pax7 fusion proteins to maintain muscle in a pre-differentiated state, our proposal will shed important light on pathological states resulting from aberrant Pax7 activity and stem cell function.

项目概要肌肉干细胞，也称为卫星细胞 (SC)，是补充肌肉所需的祖细胞群肌肉因运动而受损，或因疾病或衰老而消耗。产生肌肉的能力来自胚胎干细胞（ESC）的祖细胞将代表再生医学的重大进步。然而，尽管最近取得了进展，将小鼠和人类 ESC 区分开来仍然非常具有挑战性。肌肉祖细胞和 SC 代表肌肉组织内非常小的群体。这些限制有严重阻碍了理解肌肉干细胞及其关键调控过程的进展管理 SC 身份。转录因子 Pax7 在建立 SC 身份方面发挥着关键作用，但考虑到由于与获得 SC 相关的局限性，我们对其分子功能的理解仍然不完整。我们利用了一个系统，其中 Pax7 在 ESC 中的表达产生能够产生肌源性前体为了重新填充 SC 生态位，我们已经开始研究染色质景观和表观遗传特征了解这个群体的独特属性。通过这个系统，我们已经证明 Pax7 可以调节增强子功能和基因组拓扑。我们的目标是了解特定染色质如何环境使用最先进的基因组、生物化学和蛋白质组学来指定卫星细胞身份接近。在两个目标中，我们将：（I）研究 Pax7 如何重新建模基因组，包装染色质远距离相互作用； (II)探索Pax7如何与其他因子合作建立基因表达和体外和体内肌源性前体的基因组重新布线。我们将灭活 Pax7 相关的子集因子、增强子和已确定的调控元件，并检查它们对基因组的功能影响结构、基因表达、细胞身份和分化。众所周知，卫星细胞在衰老过程中更新效率较低，并且考虑到肌肉肿瘤（横纹肌肉瘤）异常表达 Pax7 融合蛋白以维持肌肉处于预分化状态，我们的提案将为异常 Pax7 活性和干细胞引起的病理状态提供重要的线索功能。