A transcriptional network which governs smooth muscle transition is mediated by causal coronary artery disease gene PDGFD

控制平滑肌转变的转录网络由致病性冠状动脉疾病基因 PDGFD 介导

• 批准号: 10313830
• 负责人: Chad S Weldy
• 金额: $ 7.3万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-31 至 2023-08-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10313830
• 关键词: transcriptional; network; governs; smooth; muscle

PROJECT SUMMARY OR ABSTRACT There are more than 160 genetic loci discovered which are associated with coronary artery disease (CAD), yet, outside of lipid lowering therapies, the promise of these genome wide association studies (GWAS) to identify causal genes and result in novel mechanisms for treatment has not been fulfilled. It is of critical need to identify causal genes and characterize the cellular signaling, transcriptomic, and epigenomic regulation of disease to discover novel treatments of CAD. The lab of my mentor has identified TCF21 as the CAD associated gene mapped by GWAS at 6q23.2. Single cell transcriptomic analysis and disease lesion cellular anatomy studies show that TCF21 is upregulated in SMC to promote de-differentiation, proliferation, and migration of medial SMC into the plaque where they contribute to the protective fibrous cap. We have begun to study the upstream regulation of TCF21 expression by the CAD associated gene encoding platelet derived growth factor D (PDGFD). PDGFD is a member of a receptor tyrosine kinase ligand family that has been well studied in the context of SMC phenotype and atherosclerosis and has a genetic association with CAD in humans. Gene variants resulting in increased PDGFD expression are associated with worsened CAD. These findings have led us to focus our attention on its determinative role in CAD. Importantly, PDGFD also directly regulates other validated CAD genes, including CDKN2B, LMOD1, CXCL12, SMAD3, and TWIST1, thus suggesting that it has a fundamental role in the modulation of CAD risk. We hypothesize that PDGFD promotes CAD risk through its regulation of TCF21 and other key disease related transcription factors that mediate the SMC phenotypic response to vascular stress. To address this hypothesis, we will use a novel Pdgfd-/- x ApoE- /- mouse model on a smooth muscle specific reporter background in combination with state-of-the-art technology to simultaneously evaluate single cell gene transcription and chromatin accessibility through combination scRNAseq with scATACseq in vascular tissue. We will address our primary hypothesis with two major specific aims, 1) Define the role of Pdgfd in regulating SMC phenotype and cellular and molecular features of atherosclerotic vascular tissues with an in-vivo mouse model, and 2) Map the transcriptomic program and causal epigenetic regulatory features that mediate the disease related cellular and molecular effects of Pdgfd in-vivo in the atherosclerosis mouse knockout model. This study will give us a fundamental understanding of how PDGFD influences SMC phenotypic response and thus CAD risk through modulation of chromatin accessibility and transcription factor binding. Completion of this proposal will address fundamental questions: (1) How does perturbation of Pdgfd expression affect the SMC phenotype and molecular features of atherosclerotic vascular tissue in vivo? (2) How does Pdgfd activate epigenetic and transcriptional processes which mediate SMC phenotypic modulation and thus CAD risk? Further, it is a crucial step in understanding PDGFD as a potential therapeutic target in the treatment of CAD.

项目概要或摘要 已经发现了160多个与冠状动脉疾病（CAD）相关的遗传基因座， 然而，除了降脂治疗，这些全基因组关联研究（GWAS）的前景， 鉴定致病基因并产生新治疗机制尚未实现。迫切需要 确定致病基因，并表征细胞信号传导，转录组学和表观基因组调控， 发现CAD的新疗法。我导师的实验室已经确定TCF 21为CAD 相关基因定位于6q23.2。单细胞转录组学分析和疾病病变细胞 解剖学研究表明，TCF 21在SMC中上调，以促进去分化、增殖和分化。 中膜SMC迁移到斑块中，形成保护性纤维帽。我们已经开始 研究CAD相关基因编码血小板衍生物对TCF 21表达的上游调控 生长因子D（PDGFD）。PDGFD是受体酪氨酸激酶配体家族的一员， 在SMC表型和动脉粥样硬化的背景下进行了研究，并与CAD有遗传关联， 人类导致PDGFD表达增加的基因变异与CAD恶化相关。这些 这些发现使我们将注意力集中在其在CAD中的决定性作用上。重要的是，PDGFD还直接 调节其他经验证的CAD基因，包括CDKN 2B、LMOD 1、CXCL 12、SMAD 3和TWIST 1， 这表明它在CAD风险的调节中具有重要作用。我们假设PDGFD促进 通过调节TCF 21和其他关键疾病相关转录因子介导CAD风险， SMC对血管应力的表型反应。为了解决这一假设，我们将使用一种新的Pdgfd-/- x ApoE- 在平滑肌特异性报告基因背景上的/-小鼠模型结合最新技术 同时评估单细胞基因转录和染色质可及性的技术， scRNAseq与scATACseq组合在血管组织中的表达。我们将用两个假设来解决我们的主要假设。 主要目的：1）明确Pdgfd在调节SMC表型和细胞分子水平中的作用， 使用体内小鼠模型的动脉粥样硬化血管组织的特征，以及2）绘制动脉粥样硬化血管组织的 转录组程序和因果表观遗传调控功能，介导疾病相关 动脉粥样硬化小鼠敲除模型中Pdgfd的体内细胞和分子效应。本研究 将使我们对PDGFD如何影响SMC表型反应以及CAD有一个基本的了解 通过调节染色质可及性和转录因子结合的风险。完成本提案 将解决以下基本问题：（1）Pdgfd表达的扰动如何影响SMC表型 体内动脉粥样硬化血管组织的分子特征？(2)Pdgfd如何激活表观遗传和 转录过程介导SMC表型调节，从而CAD风险？此外，这是一个至关重要的 进一步了解PDGFD作为CAD治疗中的潜在治疗靶点。