Thromboxane Receptor Signaling in Pulmonary Fibrosis

肺纤维化中的血栓素受体信号传导

• 批准号: 10307550
• 负责人: Timothy S. Blackwell
• 金额: $ 53.36万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10307550
• 关键词: 3-Dimensional; Agonist; Apoptosis; Arachidonic Acids; Architecture; Attenuated; Bleomycin; Cell Proliferation; Clinical Research; Collagen; Data; Disease; Dose; Epithelial; Exposure to; F2-Isoprostanes; Fibroblasts; Fibrosis; Free Radicals; Future; Gases; Generations; Genetic; Genetic Models; Goals; Hermanski-Pudlak Syndrome; Hour; Human; Inflammation; Intervention; Ligands; Link; Lung; Mediating; Mus; Myofibroblast; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphorylation; Pirfenidone; Pre-Clinical Model; Production; 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 Actin Staining Method; Structure of parenchyma of lung; Testing; Thromboxane A2; Thromboxane Receptor; Thromboxanes; Transforming Growth Factor beta; Translations; Ventricular; Work; antagonist; base; epithelial injury; idiopathic pulmonary fibrosis; ifetroban; improved outcome; inhibitor; mouse model; nintedanib; novel; novel therapeutic intervention; novel therapeutics; peroxidation; profibrotic fibroblast; receptor; receptor expression; therapeutic evaluation

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 尽管前列腺素及其接收器已经在肺纤维化方面进行了广泛研究，但有一个 肺中有关血栓烷A2（TXA2）和血栓烷螺旋体受体（TPR）的数据的差。 我们发现TPR在肺成纤维细胞中表达，该接收器的表达在 特发性肺纤维化（IPF）患者的成纤维细胞以及治疗的小鼠的肺成纤维细胞 与博来霉素。 TPR在小鼠中的遗传缺失或用TPR拮抗剂（Ifetroban）显着治疗 减弱的博来霉素诱导的肺纤维化。另外，TPR缺乏症或Ifetroben治疗降低 SMAD2/3磷酸化，α-平滑肌肌动蛋白（α-SMA）表达和胶原蛋白1在肺中产生 博来霉素治疗后组织和孤立的肺成纤维细胞，对炎症或上皮不影响 凋亡。相反，用血栓烷合成抑制剂（Ozagrel）处理在 抑制肺纤维化。这些发现，以及显示血栓烷表达仅是 博来霉素治疗后瞬时上调，表明纤维化中的TPR激活是介导的 通过另一种配体。 F2-异丙烷（F2-异托）是活性氧的非酶产物 物种（ROS）诱导的与TXA2具有结构相似性的花生四烯酸的过氧化，可以 激活TPR信号。用博来霉素治疗后，小鼠肺中的F2 isops持续 上调，表明这些ROS产物可以通过TPR激活介导肺纤维化。进一步 调查TPR调节纤维化的机制，我们将小鼠肺成纤维细胞暴露于F2-ISOPS（或 特定的TPR激动剂U-46619）并观察到肌纤维细胞的分化，增殖增加和SMAD2/3 磷酸化和胶原蛋白的产生，所有这些都因缺失TPR或IFEtRoban处理而阻止。 此外，在IPF患者的原发性肺成纤维细胞中，我们发现TPR拮抗作用降低了细胞增殖 α-平滑肌肌动蛋白和胶原蛋白1的表达。这些数据共同支持以下假设。 IPF患者肺中产生的活性氧物种会产生F2-异前列腺，从而激活TPR 肺成纤维细胞中的信号传导，导致肌纤维细胞分化以及持续的胶原蛋白和基质 通过SMAD/TGF-β途径的下游激活产生。阻止TPR信号的干预措施 可以提供新型的热选择以限制进行性肺纤维化。具体目标将：1） 确定TPR信号在肺成纤维细胞中的作用 TPR信号调节肌纤维细胞分化和激活的机制，3）检查 TPR抑制在人肺成纤维细胞和3-D腹球培养物中的抗纤维化作用。自TPR以来 包括IFEtroban在内的拮抗剂目前可用于人类使用，这些研究可能会设定舞台 对于未来的临床研究，针对该途径（单独或与当前药物结合使用）以改进 IPF和相关疾病的结果，其特征是进行性肺纤维化。