Thromboxane Receptor Signaling in Pulmonary Fibrosis

肺纤维化中的血栓素受体信号传导

• 批准号: 10063557
• 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/10063557
• 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; Structure of parenchyma of lung; Testing; Thromboxane A2; Thromboxane Receptor; Thromboxanes; Transforming Growth Factor beta; Translations; Ventricular; Work; base; epithelial injury; idiopathic pulmonary fibrosis; ifetroban; improved outcome; inhibitor/antagonist; mouse model; novel; novel therapeutic intervention; novel therapeutics; peroxidation; 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.

摘要 尽管已在肺纤维化中广泛研究了野牡丹素及其受体，但仍存在一种抑制野牡丹素及其受体的方法。 缺乏关于肺中血栓素A2（TXA 2）和血栓素-前列腺素受体（TPr）的数据。 我们发现，TPr在肺成纤维细胞中表达，并且这种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，以及来自治疗的小鼠的肺成纤维细胞 博莱霉素在小鼠中TPr的遗传缺失或用TPr拮抗剂（伊非曲班）治疗显著地降低了小鼠中TPr的遗传缺失。 减轻博莱霉素诱导的肺纤维化。此外，TPr缺乏或Ifetroben治疗降低了 肺组织中Smad 2/3磷酸化、α-平滑肌肌动蛋白（α-SMA）表达和胶原1的产生 博来霉素处理后的组织和分离的肺成纤维细胞，对炎症或上皮细胞无影响 凋亡与此相反，血栓素合成抑制剂（奥扎格雷）的治疗效果最低， 抑制肺纤维化。这些发现，沿着的数据显示血栓素表达仅在 博来霉素治疗后短暂上调，表明纤维化中TPr活化是由 通过另一种配体F2-异前列烷（F2-isoPs）是活性氧的非酶促产物 活性氧（ROS）诱导的花生四烯酸过氧化反应，与TXA 2具有结构相似性， 激活TPr信号。用博来霉素处理后，小鼠肺中的F2-isoPs持续升高， 上调，表明这些ROS产物可通过TPr活化介导肺纤维化。进一步 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-isoPs（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Smad 2/3 磷酸化和胶原蛋白产生，所有这些都被TPr缺失或伊非曲班处理阻断。 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 α-平滑肌肌动蛋白和胶原1的表达。总之，这些数据支持这样一种假设， IPF患者肺中产生的活性氧产生F2-异前列腺素，其激活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和基质 通过Smad/TGF-β途径的下游活化来产生。阻断TPr信号传导的干预措施 可以提供新的治疗选择，以限制进行性肺纤维化。具体目标：1） 确定肺纤维化的相关临床前模型中肺成纤维细胞中TPr信号传导的作用，2）鉴定 TPr信号调节肌成纤维细胞分化和活化的机制，以及3）检查TPr信号的作用机制。 TPr抑制在人肺成纤维细胞和3-D肺球培养物中的抗纤维化作用。自TPr 拮抗剂，包括伊非曲班，目前可用于人类使用，这些研究很可能为 未来针对该途径的临床研究（单独或与现有药物联合）， IPF和以进行性肺纤维化为特征的相关疾病的结局。