BET Bromodomain proteins as Novel Epigenetic Targets for prevention of Intimal Hyperplasia after Vascular Surgery

BET 溴结构域蛋白作为预防血管手术后内膜增生的新表观遗传靶点

基本信息

批准号：
10298010
负责人：
Lianwang Guo
金额：
$ 31.49万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-12-01 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10298010
关键词：
BET Bromodomain proteins Novel Epigenetic

项目摘要

Project Summary: Despite technological advances, arterial revascularization  especially peripheral angioplasty and bypass  often fail due to intimal hyperplasia (IH). The primary pathology of IH is the transformation of vascular smooth muscle cells (SMCs) from a quiescent state to an activated state, with multiple IH-promoting phenotypes. Currently, prevention of IH focuses on anti-proliferative agents with limited success. Moreover, a lack of insight exists into master proximal regulators that govern all of the major SMC pathogenic phenotypes, not only proliferation/migration, but also de-differentiation and inflammation. Identification and effective targeting of such master regulators would represent a major advance in anti-IH therapy. Recently, our team has identified that the bromo and extraterminal (BET) family of proteins, termed epigenetic readers, may uniquely fit this master role. Recent groundbreaking studies have revealed that the BET family of proteins can change the phenotype of different cell types, by coupling two acetyl-binding bromo-domains with acetylated key transcription factors consequently activating the transcription of a select subset of genes. We have made the exciting observation that the first-in-class BET inhibitor (JQ1) halts SMC pathogenic transformation and mitigates IH. This leads to our central hypothesis, that unlike downstream individual pathways that are subject to redundancy, BET proteins act as upstream drivers of nodal transcription factors (such as STAT3) which in turn determine downstream pathogenic SMC phenotypes. Since JQ1 globally blocks both bromo-domains in all three BET proteins, in this proposal we will differentiate the functions of the various BET proteins and bromo-domains in SMC transformation. In Aim1 we will determine which of the BET proteins dictate SMC pathogenic phenotypes and IH. We have observed that two BET proteins dramatically increase after arterial injury. In Aim2 we will further delineate which of the two bromo-domains is responsible for the BET pathogenic function. The rationale is based on our data that blocking the two bromo-domains (each in all three BET proteins) with respective inhibitors produces differential effects on SMC proliferation and inflammation. In Aim3 we will identify the key transcription factors that are governed by BET proteins, thereby mediating the BET function on SMC transformation. We have preliminarily identified STAT3 as a leading candidate. Our ultimate goal is to elucidate the specific BET protein or bromo-domain that is the most opportune target in the prevention of intimal hyperplasia. To this end, we will make use of the revolutionary CRISPR/Cas9 technology for BET protein knockout and bromo-domain mutation in the mouse genome. The proposal is novel because we will identify a key epigenetic switch that controls SMC pathogenic transformation. The research is significant because we will establish a BET protein or bromo-domain as a novel target for developing optimized therapeutic methods to treat IH and recurrent vascular disease.

项目概要：尽管技术不断进步，动脉血运重建术——尤其是外周血管成形术和搭桥术—— 常因内膜增生(IH)而失败。IH的主要病理是血管平滑肌的转变。肌细胞 (SMC) 从静止状态到激活状态，具有多种 IH 促进表型。目前，IH 的预防主要集中在抗增殖药物上，但效果有限，而且缺乏认识。存在于控制所有主要 SMC 致病表型的主近端调节因子中，不仅增殖/迁移，以及去分化和炎症的识别和有效靶向。最近，我们的团队发现，主调节器将代表抗 IH 治疗的重大进步。溴和末端外 (BET) 蛋白质家族，称为表观遗传读者，可能非常适合这位大师最近的突破性研究表明，BET 蛋白家族可以改变表型。通过将两个乙酰基结合溴结构域与乙酰化的关键转录因子偶联，对不同细胞类型进行研究因此激活了选定的基因子集的转录，我们进行了令人兴奋的观察。一流的 BET 抑制剂 (JQ1) 可以阻止 SMC 致病性转化并减轻 IH。我们的中心假设是，与受冗余影响的下游个体路径不同，BET 蛋白质充当节点转录因子（例如 STAT3）的上游驱动程序，进而决定由于 JQ1 全局阻断所有三个 BET 中的两个溴结构域。蛋白质，在本提案中，我们将区分各种 BET 蛋白质和溴结构域的功能在 Aim1 中，我们将确定哪些 BET 蛋白决定 SMC 致病表型。我们观察到动脉损伤后两种 BET 蛋白显着增加。进一步描述了两个溴结构域中的哪一个负责 BET 致病功能。基于我们的数据，该数据分别阻断两个溴结构域（每个在所有三个 BET 蛋白中）抑制剂对 SMC 增殖和炎症产生不同的影响。在 Aim3 中，我们将确定关键因素。由 BET 蛋白控制的转录因子，从而介导 SMC 上的 BET 功能我们已初步确定 STAT3 为主要候选者，我们的最终目标是阐明。特定的 BET 蛋白或溴结构域是预防内膜损伤的最合适靶点为此，我们将利用革命性的 BET 蛋白 CRISPR/Cas9 技术。该提议是新颖的，因为我们将鉴定出小鼠基因组中的基因敲除和溴结构域突变。控制 SMC 致病转化的关键表观遗传开关这项研究意义重大，因为我们将建立 BET 蛋白或溴结构域作为开发优化治疗方法的新靶点治疗 IH 和复发性血管疾病。