Regulation of lung epithelial sodium channels by cGMP

cGMP 对肺上皮钠通道的调节

• 批准号: 7760966
• 负责人: HONG-LONG JI
• 金额: $ 27.5万
• 依托单位: UNIVERSITY OF TEXAS HLTH CTR AT TYLER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7760966
• 关键词: Adult; Alveolar; Alveolar Cell; Amiloride; Amino Acids; Arts; Biochemical; Biological; Biotinylation; Cations; Cell surface; Cells; Confocal Microscopy; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Data; Development; Edema; Electrodes; Epithelial; Epithelial Cells; Gases; Goals; Heart Diseases; Human; Hydrostatic Pressure; Ions; Liquid substance; Lung; Maintenance; Measures; Mediating; Mental Depression; Molecular; Mus; Oocytes; Patch-Clamp Techniques; Pathway interactions; Patients; Permeability; Physiological; Plasma Proteins; Probability; Property; Proteins; Pulmonary Edema; RNA Splicing; Regulation; Research; Research Personnel; Site; Small Interfering RNA; Sodium Channel; Soluble Guanylate Cyclase; Techniques; Testing; Time; Transfection; Variant; Xenopus oocyte; Zinc; alveolar epithelium; base; combat; epithelial Na+ channel; fetal; in vivo; interest; monolayer; mutant; novel therapeutics; protein expression; voltage clamp

DESCRIPTION (provided by applicant): In order for gas exchange to occur in an optimum fashion, the alveolar space must remain free of fluid. Convincing evidence indicates that active Na+ transport across the alveolar epithelium in vivo contributes to the reabsorption of the fetal fluid and to the maintenance of fluid free alveolar spaces in adult lungs, especially when either alveolar permeability to plasma proteins or lung hydrostatic pressures are increased. Na+ ion reabsorption occurs through the amiloride sensitive epithelial Na+ channels (((( ENaC) and poorly characterized cation channels. Based on the exciting preliminary data presented in this application, we hypothesize that a newly described protein (( ENaC) fundamentally alters the biophysical properties of ((( ENaC-type channels and renders them sensitive to regulation via the cGMP/PKG axis. The main goals of this application are: 1) to fully characterize the biophysical and pharmacological properties of ( ENaC type channels in both Xenopus oocytes and human lung epithelial cells; 2) to investigate the regulation of ( ENaC-containing channels by cGMP in oocytes and human alveolar cells; and 3) to assess the contribution of ( ENaC to vectorial Na+ transport across human epithelial cell monolayers mounted in Ussing chambers and mouse lungs in vivo using state-of-the-art biochemical, molecular biological, electrophysiological and physiological techniques. The following specific hypotheses will be tested: 1) ( ENaC-containing homo- and heteromeric channels expressed in Xenopus oocytes have diverse biophysical properties; 2) cGMP regulates (ENaC-containing homo- and heteromeric channels but not ((( channels expressed in Xenopus oocytes; and 3) ( ENaC contributes to the non-((( ENaC Na+ currents across primary human alveolar type II (ATII) and H441 monolayers and to alveolar fluid clearance in mouse lungs. The subject matter of this research is timely and important. Results of these studies may form the molecular basis for development of new therapeutic strategies (such as cGMP delivery) to combat pulmonary edema.

描述（由申请人提供）：为了以最佳方式进行气体交换，肺泡空间必须保持无液体。令人信服的证据表明，体内跨肺泡上皮的活性 Na+ 转运有助于胎儿液体的重吸收，并有助于维持成人肺部无液体的肺泡空间，特别是当肺泡对血浆蛋白的通透性或肺静水压增加时。 Na+离子重吸收通过阿米洛利敏感的上皮Na+通道（（（（ENaC））和特征较差的阳离子通道发生。基于本申请中提供的令人兴奋的初步数据，我们假设一种新描述的蛋白质（（ENaC）从根本上改变了生物物理特性((( ENaC 型通道，并使它们对 cGMP/PKG 轴的调节敏感。该应用的主要目标是：1) 充分表征生物物理和药理学特性爪蟾卵母细胞和人肺上皮细胞中的 ( ENaC 型通道)；2) 研究卵母细胞和人肺泡细胞中 cGMP 对 ( ENaC 型通道的调节作用；3) 评估 ( ENaC 对矢量 Na+ 转运的贡献使用最先进的生化、分子生物学、电生理学和生理学技术，跨越安装在尤斯室和小鼠肺部的人上皮细胞单层。将测试：1)（非洲爪蟾卵母细胞中表达的含有 ENaC 的同聚和异聚通道具有不同的生物物理特性； 2) cGMP 调节 (ENaC 含有的同聚和异聚通道，但不调节 ((( 在非洲爪蟾卵母细胞中表达的通道；以及 3) ( ENaC 有助于非((( ENaC Na+ 电流穿过初级人类肺泡 II 型 (ATII) 和H441 单层细胞及其对小鼠肺部肺泡液清除的影响本研究的主题是及时且重要的，这些研究结果可能构成开发新疗法的分子基础。对抗肺水肿的策略（例如 cGMP 递送）。