Elucidating the chromatin-dependent mechanisms governing chronic inflammatory activation of endothelial cells in atherosclerosis.

项目摘要和摘要 尽管有标准的护理，动脉粥样硬化性心血管疾病(CVD)仍然是发病率的主要原因 以及美国的死亡率。在近一半的患者中，尽管有足够的控制，心血管疾病的风险仍然增加。 标准风险因素。在这个群体中，炎症被认为是一个关键的驱动因素。尽管有这种洞察力，但没有针对性的 对于CVD，存在抗炎疗法。因此，存在一个迫切的未得到满足的需要来阐明新的机制 动脉粥样硬化中的慢性炎症。我实验室的长期目标是了解增强剂是如何 可塑性通过对改变细胞状态的基因表达的影响来驱动动脉粥样硬化。总体目标 这一建议的目的是：1)阐明血管内皮细胞的炎性激活如何改变血管内皮细胞 2)明确BRD4在动脉粥样硬化形成中EC激活中的作用。我们的中心假设是 细胞因子和致动脉粥样硬化脂类的长期炎症激活引导了血管的持久重塑 增强剂，使基底细胞状态丧失，并激活新的炎症细胞状态。我们的假设是 根据我们以前发表的工作以及新的初步数据制定的，揭示了以下几个方面： I)人主动脉内皮细胞(HAECs)的慢性炎症刺激可导致以下一亚型的动态激活 新的超级增强子；ii)在HAEC中，这些新的增强子区域仍然存在，尽管去掉了促炎因子 刺激；iii)核心转录因子(TF)电路可以从以下序列特定的TF基序中推断出来 富含慢性炎性超级增强剂；iv)抑制BRD4可阻断腹膜炎中白细胞的募集 而动脉粥样硬化的形成部分是通过EC效应。这个项目的基本原理是，对 慢性炎症的分子介质有望识别新的药物靶点，旨在 逆转导致动脉粥样硬化的血管细胞的长期病理性激活。为了实现我们的总体目标 目标，我们将追求以下综合但不相互依赖的具体目标：1)确定如何 慢性致动脉粥样硬化刺激重塑人动脉内皮细胞染色质结构并揭示新的增强剂 2)确定Brd4在体内动脉粥样硬化形成过程中维持EC状态的功能作用。整体而言 这项工作的贡献将是阐明慢性炎症信号如何建立新的内皮细胞 通过持续的增强子激活来维持细胞状态。这项提议的核心创新是在 证明炎症通过动态的方式驱动动脉粥样硬化中的病理细胞状态的研究范式 染色质结构、增强子功能和基因表达之间的相互作用。

Project Summary and Abstract Despite standard of care, atherosclerotic cardiovascular disease (CVD) remains a leading cause of morbidity and mortality in the United States. In nearly half of patients, risk of CVD is elevated despite adequate control of standard risk factors. In this group, inflammation is proposed as a key driver. Despite this insight, no targeted anti-inflammatory therapies exist for CVD. Thus, an urgent unmet need exists to elucidate novel mechanisms of chronic inflammation in athersclerosis. The long-term goal of my laboratory is to understand how enhancer plasticity drives atherosclerosis through effects on gene expression that change cell state. The overall objectives of this proposal are to 1) to elucidate how inflammatory activation of vascular endothelial cells (ECs) alters EC identity and 2) to define the role of BRD4 in EC activation in atherogenesis. Our central hypothesis is that prolonged inflammatory activation by cytokines and proatherogenic lipids directs a durable remodeling of enhancers such that basal cell state is lost and a new inflammatory cell state is activated. Our hypothesis is formulated on the basis of our previously published work as well as new preliminary data that reveal the following: i) chronic inflammatory stimulation of human aortic ECs (HAECs) results in dynamic activation of a subset of new super enhancers; ii) in HAECs, these new enhancer regions persist despite removing the proinflammatory stimulus; iii) a core transcription factor (TF) circuitry can be inferred from sequence-specific TF motifs that are enriched at chronic inflammatory super enhancers; iv) BRD4 inhibition blocks leukocyte recruitment in peritonitis and atherogenesis in part through EC effects. The rationale for this project is that a deeper understanding of the molecular mediators of chronic inflammation holds the promise of identifying new drug targets designed to reverse the long-term, pathologic activation of vascular cells that drives atherosclerosis. To achieve our overall objectives, we will pursue the following integrated, but non-interdependent specific aims: 1) To determine how chronic, proatherogenic stimuli remodel chromatin structure and unveil new enhancers in human arterial ECs and 2) To determine the functional role of Brd4 in maintaining EC state during atherogenesis in vivo. The overall contribution of this work will be to elucidate how chronic inflammatory signaling establishes a new endothelial cell state through persistent enhancer activation. The central innovation of this proposal is a conceptual shift in research paradigm by demonstrating inflammation drives pathologic cell states in atherosclerosis by a dynamic interplay between chromatin structure, enhancer function and gene expression.