权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Frataxin loss induces endothelial dysfunction to promote pulmonary hypertension

Frataxin 损失诱导内皮功能障碍，促进肺动脉高压

基本信息

批准号：
9756463
负责人：
Miranda Kay Culley
金额：
$ 5万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9756463
关键词：
Apoptosis Apoptotic Attenuated Basic Science Binding Binding Sites Biogenesis Biological Assay Biology Blood Vessels Cardiovascular system Cell physiology Clinical Clinical Medicine Complement Complex Computer Analysis DNA Sequence Alteration Data Development Diagnosis Disease Down-Regulation Endothelial Cells Endothelium Family Friedreich Ataxia Functional disorder Future Gene Expression Genes Heart failure Histologic Human Hypertrophic Cardiomyopathy Hypoxia In Vitro Iron Knockout Mice Laboratories Left Left Ventricular Hypertrophy Link Luciferases Lung Lung diseases Measures Mediator of activation protein Medicine Mentors Metabolic dysfunction Metabolism Methods MicroRNAs Mitochondria Mitochondrial Proteins Modeling Molecular Mus Mutate Mutation Neurologic Neurologic Dysfunctions Oligonucleotides Oxidative Phosphorylation Pathway interactions Patients Phenotype Physicians Pluripotent Stem Cells Proteins Pulmonary Hypertension Pulmonary artery structure Pulmonary vessels Reactive Oxygen Species Regulation Reporter Respiration Risk Role Scaffolding Protein Scientist Site Standardization Structure Sulfur Tamoxifen Testing Training Transcript Trinucleotide Repeats Untranslated RNA Vascular Diseases Vasomotor Ventricular Virulence Factors angiogenesis cadherin 5 cofactor drug development effective therapy endothelial dysfunction enzyme activity experimental study frataxin hemodynamics improved in vitro Model in vivo indexing loss of function metal complex migration mitochondrial dysfunction mitochondrial metabolism mouse model neglect nervous system disorder new therapeutic target novel pre-doctoral pressure protein expression

项目摘要

Project Summary Background: Pulmonary hypertension (PH) is a deadly disease of the lung vasculature with a complex pathophysiology that remains largely undefined. My mentor’s laboratory established the microRNA-130/301 family as a mediator of PH development and defined a separate mechanism by which iron-sulfur (Fe-S) cluster deficiency promotes PH. Fe-S clusters are bioinorganic cofactors essential to mitochondrial and cellular function. Frataxin (FXN) is a mitochondrial protein crucial to Fe-S biogenesis. Loss of FXN due to a trinucleotide repeat mutation causes Friedreich’s ataxia (FRDA), a disease characterized by neurologic dysfunction and hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is often accompanied by PH, thought to be the result of left ventricular stiffening rather than direct dysfunction of the pulmonary vessels. However, I have found that hypoxia, a key trigger of PH, down-regulated FXN expression in pulmonary arterial endothelial cells. FXN was also decreased in the pulmonary vasculature of mice and humans with PH. Consequently, such FXN deficiency altered endothelial mitochondrial, vasomotor, apoptotic indices, thus leading to preliminary data regarding the alteration of PH in vivo. Taken together, there may be a direct role for FXN in PH. Hypothesis: FXN deficiency, induced by hypoxia or genetic mutation, disrupts endothelial metabolism and function to promote PH. Specific Aims: 1) Determine whether hypoxic down-regulation of FXN is controlled by miR-130b. I have found that the FXN transcript contains a possible binding site for the PH-relevant miR-130b. By gain- and loss- of-function methods in pulmonary arterial endothelial cells, I will determine whether hypoxia-induced miR-130b decreases FXN expression, thus defining a causative relationship among miR-130b, FXN, and Fe-S biogenesis. 2) Determine whether FXN loss attenuates mitochondrial respiration and endothelial function. In primary endothelial cells and inducible pluripotent stem cell-derived endothelial cells (iPSC-ECs) from FRDA patients, I will test the hypothesis that FXN deficiency induces Fe-S cluster-dependent mitochondrial dysfunction, resulting in endothelial phenotypic changes (e.g., apoptosis, proliferation). If successful, findings could establish a key link between hypoxia- or genetically-driven FXN loss and endothelial dysfunction consistent with PH. 3) Establish whether FXN loss and resulting mitochondrial dysfunction predisposes to PH in vivo. In a tamoxifen-dependent endothelial cell FXN knockout mouse model, I will test the hypothesis that FXN deficiency in the pulmonary endothelium promotes molecular, histologic, and hemodynamic changes consistent with PH. If successful, these results will validate an integral and direct role for FXN in the development of PH. Significance: This project is ideally structured to train me as a physician-scientist and bridge the gap between basic science and clinical medicine. I aim to contribute to the currently deficient understanding of Fe-S assembly proteins in endothelial function. I could also identify FXN as a key pathogenic factor in PH, offering the potential of diagnosing FRDA patients at risk for PH and defining FXN as a new drug target to benefit all PH patients.

项目摘要背景：肺动脉高压 (PH) 是一种致命的肺血管疾病，具有复杂的症状病理生理学在很大程度上仍然是未定义的。我导师的实验室建立了 microRNA-130/301 家族作为 PH 发展的中介者，并定义了一种单独的机制，通过该机制铁硫 (Fe-S) 簇缺乏会促进PH值。 Fe-S 簇是线粒体和细胞功能所必需的生物无机辅助因子。 Frataxin (FXN) 是一种对 Fe-S 生物合成至关重要的线粒体蛋白。由于三核苷酸重复而导致 FXN 损失突变导致弗里德赖希共济失调 (FRDA)，一种以神经功能障碍和肥大为特征的疾病心肌病。肥厚型心肌病通常伴有 PH，被认为是左心室衰竭的结果心室硬化而不是肺血管的直接功能障碍。然而，我发现缺氧， PH 的关键触发因素是肺动脉内皮细胞中 FXN 表达的下调。 FXN 也曾患有 PH 的小鼠和人类的肺血管系统减少。因此，这种 FXN 缺乏改变内皮线粒体、血管舒缩、细胞凋亡指数，从而得出有关体内 PH 值的改变。总而言之，FXN 可能在 PH 中发挥直接作用。假设：FXN 缺乏，由缺氧或基因突变引起，破坏内皮代谢和功能，促进 PH。具体目标：1) 确定 FXN 的缺氧下调是否受 miR-130b 控制。我有发现 FXN 转录本包含 PH 相关 miR-130b 的可能结合位点。通过收益和损失肺动脉内皮细胞功能丧失的方法，我将确定缺氧是否诱导 miR-130b 降低 FXN 表达，从而定义 miR-130b、FXN 和 Fe-S 生物发生之间的因果关系。 2) 确定 FXN 损失是否会减弱线粒体呼吸和内皮功能。在小学来自 FRDA 患者的内皮细胞和诱导型多能干细胞衍生的内皮细胞 (iPSC-EC)，I 将检验以下假设：FXN 缺乏会导致 Fe-S 簇依赖性线粒体功能障碍，从而导致内皮表型变化（例如细胞凋亡、增殖）。如果成功，调查结果可以建立一个关键链接缺氧或遗传驱动的 FXN 损失和与 PH 一致的内皮功能障碍之间。 3) 确定 FXN 丢失和由此导致的线粒体功能障碍是否容易导致体内PH。在一个他莫昔芬依赖性内皮细胞 FXN 敲除小鼠模型，我将测试 FXN 缺陷的假设肺内皮细胞促进与 PH 一致的分子、组织学和血流动力学变化。如果如果成功，这些结果将验证 FXN 在 PH 发展中的整体和直接作用。意义：这个项目的结构非常理想，旨在将我培养为一名医生兼科学家，并弥合两者之间的差距基础科学和临床医学。我的目标是为目前对铁硫组装的理解不足做出贡献内皮功能中的蛋白质。我还可以将 FXN 确定为 PH 的关键致病因素，提供潜在的诊断有PH风险的FRDA患者，并将FXN定义为新的药物靶点，以使所有PH患者受益。