Chromatin Regulation of Heart Valve Development

心脏瓣膜发育的染色质调控

基本信息

批准号：
8632219
负责人：
KRYN STANKUNAS
金额：
$ 36.25万
依托单位：
UNIVERSITY OF OREGON
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-12-15 至 2018-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8632219
关键词：
Adult Alleles Bicuspid Binding Biochemical Biological Markers Cell Culture Techniques Cells Chromatin Chromatin Remodeling Factor Complex Defect Development Developmental Process Diagnostic Disease Disease Progression Embryo Epigenetic Process Event Future Gene Expression Profile Gene Expression Regulation Gene Targeting Genetic Genetic Models Genome Goals Growth Heart Heart Valves Human Genetics Light Mesenchymal Mesenchyme Modeling Molecular Morphogenesis Mus Outcome Outcomes Research Pathway interactions Pattern Phenotype Population Process Regenerative Medicine Regulation Regulator Genes Research Role Signal Pathway Signal Transduction Technology Testing Tissues Transcript Transcriptional Regulation Tube Work aortic valve disorder base bicuspid aortic valve chromatin remodeling design developmental genetics empowered human disease improved interstitial loss of function mouse model neglect novel novel diagnostics preclinical study prevent programs public health relevance repaired semilunar valve therapeutic target transcription factor transcriptome sequencing

项目摘要

PROJECT SUMMARY: Semilunar valve (SLV) diseases, including bicuspid aortic valves (BAV), are remarkably common and yet their genetic and developmental origins are poorly understood. Likewise, it remains unclear how disrupted embryonic valve development progresses into overt valve disease. Our long-term goal is to understand how gene regulation drives sequential developmental processes that ultimately produce complex, patterned valves and how these processes go awry in SLV disease. These gene regulatory events require transcription factors to interface with a chromatinized genome, suggesting that chromatin regulators are key components of SLV developmental networks. One important event is an endocardial-to-mesenchymal transformation (EMT) that occurs early in valve development to populate endocardial cushions (ECs), including the proximal outflow tract (pOFT) cushions that contribute tissue to SLVs. Our objectives are to 1) understand how chromatin remodeling integrates with cell signaling during EMT, and 2) determine mechanisms by which disruptions of valve development progress into diseased SLVs. Our central hypothesis is that endocardial Brg1-associated factor (BAF) chromatin remodeling complexes interact with Wnt signaling effectors to promote pOFT EMT. As a result, when endocardial Brg1 is deleted a subtype of OFT mesenchyme is depleted. Without these cells, cusp overgrowth and fusion results in thickened and malpatterned SLVs, including BAV. The rationale for our efforts is that defining chromatin remodeling roles during EMT will shed light on how SLV disease originates. Further, our mouse models of SLV disease will enable an understanding of the cellular and molecular progression of valve disease. Our specific aims are: 1) Determine the molecular networks that the BAF complex interfaces with to direct EMT and 2) Determine mechanisms of SLV disease progression in mice lacking endocardial- lineage Brg1. In pursuit of the first Aim, we will compare cellular and molecular pOFT defects seen in unpublished genetic models disrupting Brg1 and Wnt signaling. We will apply a transformative new TU-tagging technology to define dynamic, endocardial transcriptomes dependent on each pathway. Using new cell culture approaches, we will test biochemical interactions between BAF, Wnt effectors, and chromatin in EC cells. For the second Aim, we will use genetic lineage tracing to determine contributions of EMT-derived cells to distinct SLV regions, define interactions between SLV mesenchyme sub-populations, characterize misexpressed transcripts that may drive SLV disease progression, and describe a new mouse model of adult SLV disease of potential utility in preclinical trials. Our proposed research uses novel technological and paradigmatic approaches to pursue unresolved questions of SLV development and disease. These contributions will be significant as they will shed light on the human genetics of SLV disease and inform regenerative medicine approaches. Our newly identified transcripts associated with a BAV model may represent biomarkers for disease diagnostics or therapeutic targets to prevent congenitally abnormal valves from becoming diseased.

项目概要：半月瓣 (SLV) 疾病，包括二叶式主动脉瓣 (BAV)，非常常见，但其人们对遗传和发育起源知之甚少。同样，目前还不清楚如何扰乱胚胎瓣膜发育进展为明显的瓣膜疾病。我们的长期目标是了解如何基因调控驱动顺序发育过程，最终产生复杂的、有图案的瓣膜以及这些过程如何在 SLV 疾病中出错。这些基因调控事件需要转录因子与染色质化基因组相互作用，表明染色质调节因子是 SLV 的关键组成部分发展网络。一个重要的事件是心内膜到间质的转化（EMT），发生在瓣膜发育早期，填充心内膜垫 (EC)，包括近端流出道 (pOFT) 为 SLV 提供组织的垫子。我们的目标是 1) 了解染色质如何重塑在 EMT 过程中与细胞信号传导整合，2) 确定瓣膜破坏的机制患病SLV的开发进展。我们的中心假设是心内膜 Brg1 相关因子 (BAF) 染色质重塑复合物与 Wnt 信号传导效应子相互作用，促进 pOFT EMT。作为一个结果，当心内膜 Brg1 被删除时，OFT 间充质的亚型就会耗尽。如果没有这些细胞，尖峰过度生长和融合会导致 SLV 增厚和畸形，包括 BAV。我们努力的理由确定 EMT 期间染色质重塑的作用将有助于揭示 SLV 疾病的起源。更远，我们的 SLV 疾病小鼠模型将有助于了解 SLV 疾病的细胞和分子进展瓣膜疾病。我们的具体目标是： 1) 确定 BAF 复合体接口的分子网络 2) 确定缺乏心内膜的小鼠 SLV 疾病进展的机制谱系 Brg1。为了实现第一个目标，我们将比较细胞和分子 pOFT 缺陷未发表的破坏 Brg1 和 Wnt 信号传导的遗传模型。我们将应用革命性的新 TU 标签技术来定义依赖于每个通路的动态心内膜转录组。使用新的细胞培养物方法，我们将测试 EC 细胞中 BAF、Wnt 效应子和染色质之间的生化相互作用。为了第二个目标，我们将使用遗传谱系追踪来确定 EMT 衍生细胞对不同细胞的贡献。 SLV 区域，定义 SLV 间充质亚群之间的相互作用，描述错误表达的特征可能驱动 SLV 疾病进展的转录本，并描述了成人 SLV 疾病的新小鼠模型在临床前试验中的潜在效用。我们提出的研究使用了新颖的技术和范式解决 SLV 发展和疾病的未解决问题的方法。这些贡献将意义重大，因为它们将揭示 SLV 疾病的人类遗传学并为再生医学提供信息接近。我们新发现的与 BAV 模型相关的转录本可能代表以下生物标志物：疾病诊断或治疗目标，以防止先天性异常瓣膜患病。