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）是影响白种人群体的最常见的致命遗传病。这种疾病是由囊性纤维化跨膜电导调节因子 (CFTR) 异常引起的，CFTR 是一种氯离子通道，在维持肺部健康和体内平衡方面发挥着关键作用。正常的 CFTR 门控或“激活”需要调节域 (RD) 的磷酸化和 ATP 驱动的两个核苷酸结合域 (NBD) 的二聚化。 CFTR 突变可能会产生减少氯离子转运的多种缺陷之一，包括表达减少、膜上存在减少和门控不足。高通量药物筛选项目已经发现了能够改善突变 CFTR 门控的“增效剂”化合物，其中第一个化合物 VX-770 最近在 CF 受试者的 I 期测试中显示出相当大的前景。然而，CFTR 增强剂打开突变氯离子通道的机制尚不清楚。本研究的第一个目标是详细分析几种 CFTR 增强剂化合物的机制。分离的 RD 的生化研究、全长 CFTR 的电生理学分析和酶学研究将确定对基于 cAMP 的 RD 磷酸化级联的影响。量热（热熔化）实验将评估增效剂与单个 NBD 的结合。在第二个目标中，我们将研究这些发现与小鼠体内 CFTR 增强剂激活的相关性。这将包括 AF508-CFTR（最常见的致病 CFTR 突变）和不太常见的突变，例如G551D 和 R177H。 CFTR 增强剂提供了一个机会，可以更好地了解这一重要离子通道激活的基本方式，以及 CFTR 和其他 ATP 结合盒基因家族成员所利用的结构域相互作用。为了更合理、更有效地优化人类使用的化合物，还需要了解增效剂的作用机制。公共健康相关性：囊性纤维化是美国的一种常见遗传病。在这个项目中，我们的目标是更好地定义药物类型，通过纠正上皮离子通道的功能缺陷来帮助缓解疾病。