A ROLE FOR EYA3 IN VASCULAR REMODELING AND PULMONARY ARTERIAL HYPERTENSION

项目摘要 肺动脉高压(PH)是一种病理生理状态，其特征是 肺动脉内的压力。肺动脉高压(WHO组I PH； PAH)是一种特别严重的PH，经常与右心衰竭有关， 过早死亡。没有治愈的方法，治疗只针对症状。 大约50%的PAH患者在确诊后5年内死亡。因此，有一种 迫切的、未得到满足的对新治疗策略的需求。 肺血管重塑是PAH的典型病理特征。它通向了 远端肺小动脉闭塞伴肺小动脉增加 血管阻力。血管重塑由血管内皮细胞的存活和增殖促进 氧化应激和存在条件下的肺动脉血管细胞 DNA损伤的可能性。在这里，我们提供了眼睛缺少蛋白质(EYA3)的证据 促进DNA受损细胞的存活，面临生存与凋亡的抉择。 EYA3是一种可用药且机制独特的蛋白质酪氨酸磷酸酶(PTP) 从PAH分离的肺动脉平滑肌细胞表达水平升高 病人。在原理研究的证据中，我们表明转基因小鼠携带有 EYA3 PTP结构域的失活突变可显著保护血管 慢性缺氧模型中的重构以及EYA3 PTP活性抑制物的逆转 实验性血管闭塞性肺高压大鼠模型的血管重塑。 这个项目的总体目标是建立EYA3-PTP作为一种疾病修饰剂 其在PAH病理生理学中的作用可通过Available靶向 抑制剂。这将是临床前药物靶标验证的一个关键里程碑，并将 通过在以下方面使用遗传和药理学方法来实现 两个具体目标： 目的I：阐明EYA3促进细胞增殖的分子机制(S)。 PAH的发病机制我们将使用小鼠慢性缺氧模型。血流动力学和 将对特定细胞类型的EYA3缺失进行组织病理学分析 确定EYA3在血管重塑中的细胞自体作用。单细胞 转录学和磷酸蛋白分析将被用来描述分子 促进血管重塑的机制。 目的II：确定EYA3-PTP抑制剂逆转已建立的 血管重塑我们将使用血管闭塞性肺动脉高压的大鼠模型，并评估 最安全有效的EYA3靶向药物干预模式。 这项提议的总体影响是，它将定义一个有针对性的信令 肺血管病理生物学特点的发病机制 PAH，证明EYA3-PTP抑制剂是可行的先导化合物 PAH疗法的发展，并提供对以前未探索的 PAH发病的分子机制。

Project Summary Pulmonary Hypertension (PH) is a pathophysiologic condition characterized by elevated pressure in the pulmonary arteries. Pulmonary arterial hypertension (WHO Group I PH; PAH) is a particularly severe form of PH frequently associated with right heart failure and premature death. There is no cure, and treatments only target the symptoms. Approximately 50% of PAH patients die within 5 years of diagnosis. There is therefore a compelling, unmet need for new therapeutic strategies. Pulmonary vascular remodeling is the defining pathological feature of PAH. It leads to occlusion of distal pulmonary arterioles, with accompanying increase in pulmonary vascular resistance. Vascular remodeling is promoted by the survival and proliferation of pulmonary arterial vascular cells under conditions of oxidative stress and in the presence of DNA damage. Here we provide evidence that the Eyes Absent protein (EYA3) promotes survival of DNA damaged cells facing a survival-versus-apoptosis decision. EYA3 is a druggable and mechanistically unique protein tyrosine phosphatase (PTP) present at elevated levels in pulmonary arterial smooth muscle cells isolated from PAH patients. In proof of principle studies, we show that transgenic mice harboring an inactivating mutation in the EYA3 PTP domain are significantly protected from vascular remodeling in a chronic hypoxia model, and that inhibitors of EYA3 PTP activity reverse vascular remodeling in a rat model of experimental angio-obliterative PH. The overall goal of this project is to establish the EYA3-PTP as a disease-modifying target whose function in the pathophysiology of PAH can be targeted by available inhibitors. This will be a critical milestone in pre-clinical drug target validation and will be achieved through the use of genetic and pharmacological approaches in the following two Specific Aims: Aim I: To elucidate the molecular mechanism(s) through which EYA3 promotes the pathogenesis of PAH we will use a murine chronic hypoxia model. Hemodynamic and histopathological analyses upon cell-type specifc EYA3 deletion will be conducted to identify the cell-autuonomous roles of EYA3 in vascular remodeling. Single-cell transcriptomics and phospho-protein analyses will be used to delineate the molecular mechanims contributing to vascular remodeling. Aim II: To establish the effectiveness of EYA3-PTP inhibitors in reversing established vascular remodeling we will use a rat model of angio-obliterative PAH and evaluate the most safe and effective modes of EYA3-targeted pharmacological intervention. The overall impact of this proposal is that it will define a targetable signaling mechanism that contributes to the characteristic pulmonary vascular pathobiology in PAH, demonstrate that EYA3-PTP inhibitors are viable lead compounds for the development of PAH therapeutics, and provide insights into a previously unexplored molecular mechanism contributing to PAH pathology.