Alveolar epithelial B2-adrenergic receptors

肺泡上皮 B2 肾上腺素能受体

• 批准号: 7431602
• 负责人: Phillip H Factor
• 金额: $ 34.12万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7431602
• 关键词: A kinase anchoring protein; Accounting; Active Biological Transport; Acute; Acute Lung Injury; Adaptor Signaling Protein; Address; Adenylate Cyclase; Adrenergic Agonists; Adrenergic Receptor; Affect; Agonist; Alveolar; Alveolus; Animal Model; Binding; Binding Proteins; Cardiac Myocytes; Carrier Proteins; Cell membrane; Cells; Complement; Complex; Condition; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cystic Fibrosis Transmembrane Conductance Regulator; Cytoskeleton; Data; Databases; Disruption; Edema; Epithelial; Epithelial Cells; Exposure to; GTP-Binding Proteins; Generations; Goals; Hour; Human; Immunoprecipitation; In Vitro; Injury; Ion Transport; Ligands; Liquid substance; Lung; Macromolecular Complexes; Mass Spectrum Analysis; Measurement; Measures; Mediating; Membrane; Metabolic Clearance Rate; Modeling; Molecular; Mus; Na(+)-K(+)-Exchanging ATPase; Organ; Oxygen; Patients; Peptides; Phosphorylation; Physiological; Preparation; Procaterol; Production; Protein Overexpression; Proteins; Pulmonary Edema; Purpose; Receptor Activation; Regulation; Reporting; Research Personnel; Resolution; Signal Transduction; Speed; Structure; Testing; Therapeutic; alveolar epithelium; apical membrane; epithelial Na+ channel; improved; injured; lung injury; phosphoric diester hydrolase; programs; protein function; protein protein interaction; receptor; receptor upregulation; research study; response; scaffold; A kinase anchoring protein; Accounting; Active Biological Transport; Acute; Acute Lung Injury; Adaptor Signaling Protein; Address; Adenylate Cyclase; Adrenergic Agonists; Adrenergic Receptor; Affect; Agonist; Alveolar; Alveolus; Animal Model; Binding; Binding Proteins; Cardiac Myocytes; Carrier Proteins; Cell membrane; Cells; Complement; Complex; Condition; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cystic Fibrosis Transmembrane Conductance Regulator; Cytoskeleton; Data; Databases; Disruption; Edema; Epithelial; Epithelial Cells; Exposure to; GTP-Binding Proteins; Generations; Goals; Hour; Human; Immunoprecipitation; In Vitro; Injury; Ion Transport; Ligands; Liquid substance; Lung; Macromolecular Complexes; Mass Spectrum Analysis; Measurement; Measures; Mediating; Membrane; Metabolic Clearance Rate; Modeling; Molecular; Mus; Na(+)-K(+)-Exchanging ATPase; Organ; Oxygen; Patients; Peptides; Phosphorylation; Physiological; Preparation; Procaterol; Production; Protein Overexpression; Proteins; Pulmonary Edema; Purpose; Receptor Activation; Regulation; Reporting; Research Personnel; Resolution; Signal Transduction; Speed; Structure; Testing; Therapeutic; alveolar epithelium; apical membrane; epithelial Na+ channel; improved; injured; lung injury; phosphoric diester hydrolase; programs; protein function; protein protein interaction; receptor; receptor upregulation; research study; response; scaffold

DESCRIPTION (provided by applicant): The clearance of pulmonary edema fluid occurs by means of active Na+ transport by alveolar epithelial cells. It is widely accepted that the coordinated function of Na+ and CI- channels in the apical membrane and Na,K-ATPase in the basolateral aspect of alveolar epithelial cells creates a transepithelial osmotic gradient that causes fluid to exit the alveolus. It has been observed in animal models and humans that in some types of lung injury active Na+ transport is impaired. Substantial experimental data suggests that beta2-adrenergic agonists accelerate active Na+ transport and speed edema resolution. These data offer the possibility that beta2-adrenergic agonists may be useful for the treatment of pulmonary edema. The overall goal of our experimental program is to improve our understanding of how beta2-adrenergic receptors (beta2AR) regulate alveolar active Na+ transport. We have reported that mice with no beta1 or beta2 adrenergic receptors have normal total lung cAMP levels but are unable to upregulate active Na+ transport in response to excess alveolar fluid. This finding led us to consider that beta2AR regulation of active Na+ transport requires more than cAMP production. It has recently been noted that the a2AR interacts with scaffold and adaptor proteins that are in close proximity to beta2AR effector molecules such as PKA and CFTR and, anchor it to the sub-membrane cytoskeleton. These protein-protein interactions allow for compartmentalized signaling and tight regulation of beta2AR function. In preparation for this competitive renewal we conducted preliminary immunoprecipitation studies that suggest that alveolar epithelial (2ARS form macromolecular complexes with other transport proteins. This new data led us to hypothesize that: beta2AR regulation of alveolar epithelial active transport occurs via highly regulated interactions with scaffold and/or adaptor proteins. If confirmed, this hypothesis would support a new paradigm where beta2AR regulation of alveolar active Na+ transport is dependent not only on cAMP generation but also formation of a macromolecular regulatory complex at the cell membrane. To address this hypothesis we have formulated the following three specific aims: Aim 1: Determine if beta2AR-scaffold/adaptor protein interactions are necessary for regulation of beta2AR sensitive active Na+ transport in alveolar epithelial cells in vitro. Aim 2: Ascertain if beta2AR -scaffold interactions are necessary for beta2AR regulation of active Na+ transport in normal lungs. Aim 3: Determine if acute lung injury alters beta2AR -scaffold/adaptor protein interactions in mouse lung. The focused studies in this competitive renewal application are structured to define which scaffold and adaptor proteins alveolar beta2AR interacts with, which are required for regulation of active Na+ transport, and if these proteins are affected by acute lung injury. These studies offer an opportunity to expand our understanding of the mechanisms by which the alveolar epithelium regulates active Na+ transport. It is hoped that our studies will identify injury-induced alterations in beta2AR protein-protein interactions that would be amenable to therapeutic manipulation for purposes of speeding resolution of pulmonary edema in the millions of patients with acute pulmonary edema each year.

描述（由申请人提供）：肺水肿流体的清除是通过肺泡上皮细胞的主动Na+转运进行的。 人们普遍认为，肺泡上皮细胞基底外侧的顶端膜中Na+和CI-通道的协调功能会产生一种旋转的渗透梯度，从而导致流体退出肺泡。 在动物模型和人类中已经观察到，在某些类型的肺损伤中，主动Na+转运受损。大量的实验数据表明，β2-肾上腺素能激动剂加速了活跃的Na+运输和速度水肿分辨率。 这些数据提供了β2-肾上腺素能激动剂的可能性，可用于治疗肺水肿。 我们实验计划的总体目标是提高我们对β2-肾上腺素能受体（BETA2AR）如何调节肺泡活性Na+转运的理解。 我们报告说，没有beta1或beta2肾上腺素能受体的小鼠的总肺营地水平正常，但由于响应过量的肺泡液而无法上调主动的Na+转运。 这一发现使我们认为，主动NA+运输的Beta2AR调节比营地生产还需要更多。 最近已经注意到，A2AR与支架和衔接子蛋白相互作用，这些蛋白与Beta2AR效应子分子（如PKA和CFTR）非常接近，并将其固定在亚膜细胞骨架上。 这些蛋白质 - 蛋白质相互作用允许对β2AR功能的分隔信号传导和严格调节。为了准备这种竞争性更新，我们进行了初步的免疫沉淀研究，该研究表明肺泡上皮（2ARS与其他转运蛋白形成大分子分子复合物。这些新数据导致我们假设：β2AR通过高度调节的肺泡上皮相互作用通过与Scaffold和Addapter的蛋白质相互作用，β2AR调节肺泡上皮运输的调节。 如果得到证实，该假设将支持一种新的范式，在这种范式中，β2AR调节肺泡活性Na+转运不仅取决于营地的产生，还取决于细胞膜上的大分子调节复合物的形成。 为了解决这一假设，我们已经提出了以下三个特定目的：目标1：确定beta2ar-caffold/apapter蛋白相互作用是否对于调节体外肺泡上皮细胞中β2AR敏感活性Na+转运是否需要。 AIM 2：确定beta2AR -Scaffold相互作用对于正常肺中主动Na+转运的β2AR相互作用是否需要。 AIM 3：确定急性肺损伤是否改变了小鼠肺中的β2AR -scaffold/适配器蛋白相互作用。 该竞争性更新应用中的重点研究结构化，以定义哪种脚手架和衔接子蛋白肺泡β2AR与活性Na+转运的调节所必需的，以及这些蛋白是否受急性肺损伤的影响。 这些研究提供了一个机会，可以扩展我们对肺泡上皮调节主动Na+转运的机制的理解。 希望我们的研究能够确定β2AR蛋白 - 蛋白质相互作用的损伤诱导的改变，这些变化可容纳治疗性操作，以便在每年数百万急性肺水肿的患者中加速肺水肿。