A ROLE FOR EYA3 IN VASCULAR REMODELING AND PULMONARY ARTERIAL HYPERTENSION

项目摘要 肺动脉高压（PH）是一种病理生理状况，其特征在于肺动脉高压（PH）升高。 肺动脉的压力肺动脉高压（WHO I组PH; PAH）是一种特别严重的PH形式，经常与右心衰竭相关， 过早死亡没有治愈方法，治疗只能针对症状。 大约50%的PAH患者在诊断后5年内死亡。因此有 对新的治疗策略的迫切的、未满足的需求。 肺血管重构是PAH的定义性病理特征。它导致 远端肺小动脉闭塞，伴肺动脉高压增加 血管阻力血管重塑是由血管内皮细胞的存活和增殖促进的。 肺动脉血管细胞在氧化应激条件下和存在 DNA损伤。在这里，我们提供证据表明，眼睛缺席蛋白（EYA 3） 促进DNA受损细胞的存活，面临存活与凋亡的决定。 EYA 3是一种可药物化且机制独特的蛋白酪氨酸磷酸酶（PTP） 在PAH分离的肺动脉平滑肌细胞中以升高水平存在 患者在原理研究的证明中，我们表明， EYA 3 PTP结构域中的失活突变显著保护血管内皮细胞免受血管内皮细胞的损伤。 在慢性缺氧模型中，EYA 3 PTP活性抑制剂逆转了心肌重塑， 实验性血管闭塞性PH大鼠模型中的血管重塑。 该项目的总体目标是将EYA 3-PTP建立为疾病修饰基因。 靶点，其在PAH病理生理学中的功能可以通过可用的 抑制剂的这将是临床前药物靶点验证的一个重要里程碑， 通过使用遗传和药理学方法， 两个具体目标： 目的一：阐明EYA 3促进细胞凋亡的分子机制。 PAH的发病机制，我们将使用鼠慢性缺氧模型。血流动力学和 对细胞类型特异性EYA 3缺失进行组织病理学分析， 确定EYA 3在血管重塑中的细胞自体作用。单细胞 转录组学和磷蛋白分析将用于描绘分子 促进血管重塑的机制。 目的II：确定EYA 3-PTP抑制剂在逆转已建立的 血管重塑，我们将使用血管闭塞性PAH的大鼠模型，并评估 最安全有效的EYA 3靶向药物干预模式。 这个提议的总体影响是，它将定义一个有针对性的信令 导致肺血管病理学特征的机制 PAH，证明EYA 3-PTP抑制剂是治疗PAH的可行先导化合物。 PAH治疗方法的开发，并提供对以前未探索的 导致PAH病理的分子机制。

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.