Potentiation of Mutant CFTR Activity

突变 CFTR 活性的增强

• 批准号: 7676963
• 负责人: Louise Clare Pyle
• 金额: $ 3.35万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-22 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7676963
• 关键词: Affect; Anions; Binding; Biochemical; Biological Assay; Caucasians; Caucasoid Race; Chemosensitization; Chloride Channels; Chloride Ion; Chlorides; Clinical; Clinical Trials; Cyclic AMP; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Defect; Dimerization; Disease; Disease model; Epithelial; Failure; Family member; Gene Family; Health; Hereditary Disease; Homeostasis; Human; In Vitro; Individual; Induced Mutation; Intervention; Intestines; Ion Channel; Ion Channel Gating; Length; Lung; Measurement; Membrane; Mus; Mutation; Nose; Nucleotides; Pharmaceutical Preparations; Phase; Phosphorylation; Physiological; Population; Preclinical Drug Evaluation; Production; Proteins; Regulation; Role; Signal Transduction; Surface; Testing; VX-770; base; improved; in vivo; melting; mutant; programs; public health relevance; research study

DESCRIPTION (provided by applicant): Cystic fibrosis (CF) is the most common lethal genetic disease affecting Caucasian populations. The illness is caused by abnormalities in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel that serves a critical role maintaining lung health and homeostasis. Normal CFTR gating or "activation" requires phosphorylation of the regulatory domain (RD) and ATP-driven dimerization of the two nucleotide binding domains (NBDs). CFTR mutations may engender one of a number of defects that reduce chloride transport, including reduced expression, decreased presence at the membrane, and insufficient gating. 'Potentiator' compounds capable of improving the gating of mutant CFTR have been discovered by high-throughput drug screening programs, and the first of these compounds, VX-770, has recently shown considerable promise as part of Phase I testing in CF subjects. However, the mechanism(s) by which CFTR potentiators open the mutant chloride channel are not known. The first Aim of this study encompasses a detailed analysis of the mechanisms underlying several CFTR potentiator compounds. Biochemical study of isolated RD, electrophysiologic analysis of full-length CFTR, and enzymatic studies will determine effects on the cAMP-based RD phosphorylation cascade. Calorimetric (thermal melting) experiments will evaluate potentiator binding to individual NBDs. In the second Aim, we will investigate the relevance of these findings to in vivo potentiator activation of CFTR in mice. This will include both AF508-CFTR, the most common disease-causing CFTR mutation, and less frequent mutations, e.g. G551D and R177H. Potentiators of CFTR present an opportunity to better understand the basic means underlying activation of this important ion channel, and the domain interactions utilized by CFTR and other ATP binding cassette gene family members. An understanding of potentiator mechanism of action is also required for a more rational and efficient approach to optimizing compounds such as these for human use. PUBLIC HEALTH RELEVANCE: Cystic Fibrosis is a common genetic disease in the U.S. In this project we aim to better define the types of drugs that will help alleviate the disease by correcting defective function of the epithelial ion channel.

描述（由申请人提供）：囊性纤维化（CF）是影响高加索人群的最常见的致死性遗传疾病。这种疾病是由囊性纤维化跨膜传导调节因子（CFTR）异常引起的，CFTR是一种氯离子通道，在维持肺健康和体内平衡方面起着关键作用。正常的CFTR门控或“激活”需要调节结构域（RD）的磷酸化和两个核苷酸结合结构域（NBD）的ATP驱动的二聚化。CFTR突变可能会导致一系列减少氯离子转运的缺陷之一，包括表达减少、膜存在减少和门控不足。高通量药物筛选程序已经发现了能够改善突变CFTR门控的“增效剂”化合物，并且这些化合物中的第一种VX-770最近显示出相当大的前景，作为CF受试者I期测试的一部分。然而，CFTR增效剂打开突变氯离子通道的机制尚不清楚。本研究的第一个目的包括详细分析几种CFTR增效剂化合物的机制。分离RD的生化研究、全长CFTR的电生理学分析和酶研究将确定对基于cAMP的RD磷酸化级联的影响。量热（热熔融）实验将评价增效剂与单个NBD的结合。在第二个目标中，我们将研究这些发现的相关性，在小鼠体内增强剂激活CFTR。这将包括AF 508-CFTR（最常见的致病CFTR突变）和较不常见的突变（例如G551 D和R177 H）。CFTR的增效剂提供了一个机会，以更好地了解基本手段激活这一重要的离子通道，并利用CFTR和其他ATP结合盒基因家族成员的结构域相互作用。了解增效剂的作用机制也需要一个更合理和有效的方法来优化化合物，如这些用于人类使用。公共卫生关系：囊性纤维化是一种常见的遗传性疾病在美国在这个项目中，我们的目标是更好地定义药物的类型，这将有助于通过纠正上皮离子通道的功能缺陷来缓解疾病。