Thromboxane Receptor Signaling in Pulmonary Fibrosis

肺纤维化中的血栓素受体信号传导

基本信息

批准号：
10526417
负责人：
Jonathan Andrew Kropski
金额：
$ 53.36万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-12-01 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10526417
关键词：
3-Dimensional Actins Agonist Apoptosis Arachidonic Acids Architecture Attenuated Bleomycin Cell Proliferation Clinical Research Collagen Data Disease Dose Epithelium Exposure to F2-Isoprostanes Fibroblasts Fibrosis Free Radicals Future Gases Generations Genetic Genetic Models Goals Hermanski-Pudlak Syndrome Hour Human Inflammation Intervention Invaded Ligands Link Lung Mediating Mus Myofibroblast Pathway interactions Patients Pharmaceutical Preparations Phenotype Phosphorylation Pirfenidone Pre-Clinical Model Production Proliferating Prostaglandins Prostaglandins I Pulmonary Fibrosis Radiation Reactive Oxygen Species Receptor Activation Receptor Inhibition Receptor Signaling Recurrence Research Personnel Role Signal Pathway Signal Transduction Smooth Muscle Structure of parenchyma of lung Testing Thromboxane A2 Thromboxane Receptor Thromboxanes Transforming Growth Factor beta Translations Work antagonist epithelial injury idiopathic pulmonary fibrosis ifetroban improved outcome inhibitor mouse model nintedanib novel novel therapeutic intervention novel therapeutics peroxidation profibrotic fibroblast receptor receptor expression right ventricular remodeling therapeutic evaluation

项目摘要

ABSTRACT Although prostaglandins and their receptors have been studied extensively in pulmonary fibrosis, there is a paucity of data regarding thromboxane A2 (TXA2) and the thromboxane-prostanoid receptor (TPr) in the lungs. We found that TPr is expressed in lung fibroblasts and that expression of this receptor is upregulated in fibroblasts from patients with idiopathic pulmonary fibrosis (IPF), as well as lung fibroblasts from mice treated with bleomycin. Genetic deletion of TPr in mice or treatment with a TPr antagonist (Ifetroban) markedly attenuated bleomycin-induced lung fibrosis. In addition, TPr deficiency or Ifetroben treatment reduced Smad2/3 phosphorylation, α-smooth muscle actin (α-SMA) expression, and collagen 1 production in lung tissue and isolated lung fibroblasts following bleomycin treatment, without effects on inflammation or epithelial apoptosis. In contrast, treatment with a thromboxane synthesis inhibitor (Ozagrel) was minimally effective at inhibiting lung fibrosis. These findings, along with data showing that thromboxane expression was only transiently upregulated following bleomycin treatment, suggested that TPr activation in fibrosis is mediated through an alternative ligand. F2-isoprostanes (F2-isoPs) are a non-enzymatic product of reactive oxygen species (ROS)-induced peroxidation of arachidonic acid that have structural similarities to TXA2 and can activate TPr signaling. Following treatment with bleomycin, F2-isoPs in mouse lungs were persistently upregulated, suggesting that these ROS products could mediate lung fibrosis via TPr activation. To further investigate mechanisms by which TPr regulates fibrosis, we exposed mouse lung fibroblasts to F2-isoPs (or the specific TPr agonist U-46619) and observed myofibroblast differentiation, increased proliferation, and Smad2/3 phosphorylation, and collagen production, all of which were blocked by deletion of TPr or Ifetroban treatment. Further, in primary lung fibroblasts from IPF patients, we found that TPr antagonism reduced cell proliferation and expression of α-smooth muscle actin and collagen 1. Together, these data support the hypothesis that reactive oxygen species produced in the lungs of IPF patients generate F2-isoprostanes which activate TPr signaling in lung fibroblasts, leading to myofibroblast differentiation and persistent collagen and matrix production through downstream activation of the Smad/TGF-β pathway. Interventions that block TPr signaling could provide novel therapeutic options to limit progressive pulmonary fibrosis. Specific Aims will: 1) determine the role of TPr signaling in lung fibroblasts in relevant pre-clinical models of lung fibrosis, 2) identify mechanisms by which TPr signaling regulates myofibroblast differentiation and activation, and 3) examine the anti-fibrotic effects of TPr inhibition in human lung fibroblasts and 3-D pulmosphere cultures. Since TPr antagonists, including Ifetroban, are currently available for human use, these studies are likely to set the stage for future clinical studies targeting this pathway (alone or in combination with current drugs) to improve outcomes in IPF and related diseases characterized by progressive pulmonary fibrosis.

抽象的尽管前列腺素及其受体主要在肺纤维化中进行研究，但仍有缺乏有关肺部血栓素 A2 (TXA2) 和血栓素-前列腺素受体 (TPr) 的数据。我们发现 TPri 在肺成纤维细胞中表达，并且该受体的表达在肺成纤维细胞中上调。来自特发性肺纤维化 (IPF) 患者的成纤维细胞，以及来自接受治疗的小鼠的肺成纤维细胞使用博来霉素对小鼠进行TPr基因缺失或使用TPr拮抗剂（伊非曲班）治疗效果显着。此外，TPr 缺乏或 Ifetroben 治疗可减轻博来霉素诱导的肺纤维化。肺中 Smad2/3 磷酸化、α-平滑肌肌动蛋白 (α-SMA) 表达和胶原蛋白 1 生成博来霉素治疗后的组织和分离的肺成纤维细胞，对炎症或上皮细胞没有影响相比之下，用血栓素合成抑制剂（Ozagrel）治疗对细胞凋亡的作用最低。这些发现以及数据表明血栓素的表达只是抑制肺纤维化。博来霉素治疗后短暂上调，表明纤维化过程中 TPR 激活是介导的 F2-异前列腺素 (F2-isoPs) 是活性氧的非酶促产物。物种（ROS）诱导的花生四烯酸过氧化，其结构与 TXA2 相似，可以激活TPr信号传导后，小鼠肺部的F2-isoPs持续存在。上调，表明这些 ROS 产物可以通过 Tpr 激活介导肺纤维化。为了研究 TPR 调节纤维化的机制，我们将小鼠肺成纤维细胞暴露于 F2-isoP（或特异性 TPR 激动剂 U-46619）并观察到肌成纤维细胞分化、增殖增加和 Smad2/3 磷酸化和胶原蛋白生成，所有这些都通过删除 TPR 或伊非曲班治疗而被阻断。此外，在 IPF 患者的原代肺成纤维细胞中，我们发现 Tpr 拮抗作用降低了细胞增殖以及 α-平滑肌肌动蛋白和胶原蛋白的表达 1。这些数据共同支持以下假设： IPF 患者肺部产生的活性氧会生成 F2-异前列腺素，从而激活 TPR 肺成纤维细胞中的信号传导，导致肌成纤维细胞分化和持久的胶原蛋白和基质通过下游激活 Smad/TGF-β 通路来阻断 Tpr 信号传导。可以提供限制进行性肺纤维化的新治疗选择，具体目标是：1) 确定 Tpr 信号在肺纤维化相关临床前模型中肺成纤维细胞中的作用，2) 确定 Tpr 信号传导调节肌成纤维细胞分化和激活的机制，以及 3) 检查自TPr以来，TPr抑制对人肺成纤维细胞和3-D脉冲层培养物的抗纤维化作用。包括伊非曲班在内的拮抗剂目前可供人类使用，这些研究可能会奠定基础未来针对该途径的临床研究（单独或与现有药物联合）以改善 IPF 和以进行性肺纤维化为特征的相关疾病的结果。