Role of GPR116 in Alveolar Homeostasis

GPR116 在肺泡稳态中的作用

基本信息

批准号：
9078096
负责人：
James Patrick Bridges
金额：
$ 40.26万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-03-18 至 2021-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9078096
关键词：
Actins Acute Lung Injury Adult Alveolar Alveolar Macrophages Amino Acids Attenuated Biological Assay Breathing Cell membrane Cells Child Coupled Data Disease Epithelial Epithelial Cells Epithelium Equilibrium F-Actin Functional disorder G-Protein-Coupled Receptors GTP-Binding Proteins Gases Genetic Goals Homeostasis Human In Vitro Infant respiratory distress Inflammation Lipid Peroxidation Lung Lung diseases Mediating Modeling Molecular Molecular Target Mus Neutrophilia Orphan Oxidative Stress Pathogenesis Pathologic Pathway interactions Patients Phospholipids Physiological Proteins Pulmonary Alveolar Proteinosis Pulmonary Surfactants Respiratory Failure Role Signal Pathway Signal Transduction Source Structure of parenchyma of lung Testing Therapeutic Tissues Type II Epithelial Receptor Cell Wild Type Mouse Work alveolar homeostasis alveolar type II cell base clinically relevant in vivo insight loss of function mRNA Expression mouse model novel peroxidation phosphoproteomics pre-clinical prevent public health relevance release of sequestered calcium ion into cytoplasm respiratory distress syndrome surfactant synthetic peptide therapeutic target uptake

项目摘要

DESCRIPTION (provided by applicant): Pulmonary alveolar homeostasis is dependent upon balanced airway and tissue surfactant pools. Quantitative and qualitative alterations in alveolar surfactant pools are associated with inflammation and tissue destruction in severe lung diseases including infant respiratory distress syndrome, many forms of acute lung injury and pulmonary alveolar proteinosis. Identification of a physiologically-dominant molecular pathway within alveolar epithelial cells that senses and regulates endogenous alveolar surfactant pools, coupled with the ability to pharmacologically modulate it both positively and negatively, would be a major therapeutic advance for patients with lung diseases associated with pulmonary surfactant disorders. Preliminary data supporting this application strongly implicate an alveolar epithelial cell-centric, G protein-dependent pathway driven by GPR116 as a druggable molecular target to modulate endogenous alveolar surfactant pools. We demonstrate that GPR116 is abundantly expressed in human and mouse lung, and pulmonary epithelium-specific deletion of GPR116 in mice results in early and progressive accumulation of alveolar surfactant associated with phospholipid peroxidation, neutrophilia and alveolar remodeling, culminating in respiratory failure. We have identified a novel synthetic peptide that is sufficient to activate G protein-dependent signaling downstream of mouse and human GPR116 in vitro and suppress alveolar surfactant levels in mice in vivo, providing proof-of- concept that GPR116 is a plausible therapeutic target to modulate endogenous alveolar surfactant pools in humans. Our central hypothesis is that epithelial GPR116 regulates alveolar surfactant homeostasis via Gq/11- driven modulation of actin cytoskeletal dynamics in alveolar type II cells. Our goal in this projec is to systematically define the signaling pathways by which GPR116 controls surfactant homeostasis using cell-based assays and mouse genetics through completion of three integrated aims. In the first aim, we will test the hypothesis that GPR116-dependent activation of a Gq/G11-PKCδ-dependent pathway induces cortical F-actin assembly to suppress surfactant secretion and/or decrease surfactant uptake in alveolar type II cells. In the second aim, we will test the hypothesis that activation of epithelial GPR116 is sufficient to restore surfactant homeostasis in two established mouse models of alveolar surfactant overload, Csf2rb-/- and Sftpd-/- mice. In the third aim, we will test the hypothesis that increased alveolar surfactant pools initiate alveolar macrophage oxidative stress and subsequent alveolar simplification in Gpr116-/- mice. Successful completion of these specific aims will delineate the signaling pathways by which GPR116 senses and regulates surfactant and alveolar homeostasis. The long-term goal of this work is to identify potential therapeutic targets, including GPR116 itself, that will permit modulation of endogenous surfactant levels to treat human lung diseases associated with surfactant dysfunction.

描述（由申请人提供）：肺泡稳态取决于气道和组织表面活性剂池的平衡。肺泡表面活性剂池的定量和定性改变与严重肺部疾病（包括婴儿呼吸窘迫综合征、多种形式的急性肺疾病）中的炎症和组织破坏有关。肺泡上皮细胞内感知和调节内源性肺泡的生理主导分子途径的鉴定。表面活性剂池，加上对其进行正向和负向药理学调节的能力，对于患有与肺表面活性剂紊乱相关的肺部疾病的患者来说将是一个重大的治疗进展，支持该应用的初步数据表明以肺泡上皮细胞为中心的、G蛋白依赖性的。我们证明 GPR116 在人和小鼠的肺和肺中大量表达。小鼠上皮特异性删除 GPR116 会导致与磷脂过氧化、中性粒细胞增多和肺泡重塑相关的肺泡表面活性剂的早期和渐进性积累，最终导致呼吸衰竭。我们已经鉴定出一种足以激活下游 G 蛋白依赖性信号传导的新型合成肽。体外研究小鼠和人类 GPR116 并抑制小鼠体内肺泡表面活性剂水平，从而证明 GPR116 是一个合理的治疗靶点我们的中心假设是上皮 GPR116 通过 Gq/11 驱动的 II 型肺泡细胞肌动蛋白细胞骨架动力学调节来调节肺泡表面活性剂稳态。其中 GPR116 使用基于细胞的测定和小鼠遗传学通过完成三个综合目标来控制表面活性剂稳态。目标，我们将测试以下假设：Gq/G11-PKCδ 依赖性途径的 GPR116 依赖性激活诱导皮质 F-肌动蛋白组装，从而抑制 II 型肺泡细胞中表面活性剂的分泌和/或减少表面活性剂的摄取。将测试以下假设：上皮 GPR116 的激活足以在两个已建立的肺泡表面活性剂过载小鼠模型中恢复表面活性剂稳态，在第三个目标中，我们将测试 Csf2rb-/- 和 Sftpd-/- 小鼠的假设，即增加的肺泡表面活性剂池会引发 Gpr116-/- 小鼠的肺泡巨噬细胞氧化应激和随后的肺泡简化，这些具体目标将成功完成。 GPR116 感知和调节表面活性剂和肺泡稳态的信号通路这项工作的长期目标是确定潜在的治疗靶点，包括 GPR116 本身，这将允许调节内源性表面活性剂水平，以治疗与表面活性剂功能障碍相关的人类肺部疾病。