Molecular pharmacology and physiology of kidney potassium transport

肾脏钾转运的分子药理学和生理学

• 批准号: 8135340
• 负责人: Jerod S. Denton
• 金额: $ 26.18万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8135340
• 关键词: Affinity; Amino Acids; Animals; Architecture; Arrhythmia; Atrial Fibrillation; Binding; Binding Sites; Calcium Channel; Cardiac; Cations; Cell physiology; Computational Technique; Development; Disease; Distal; Diuresis; Diuretics; Drug Delivery Systems; Duct (organ) structure; Edema; Electrophysiology (science); GTP-Binding Proteins; Hypertension; KCNJ1 gene; Kidney; Lead; Libraries; Location; Methods; Molecular; Molecular Models; Molecular Probes; Molecular Structure; Mutagenesis; Nephrons; Nervous System Physiology; Pharmaceutical Chemistry; Pharmaceutical Preparations; Pharmacology; Physiological; Physiological Processes; Physiology; Play; Potassium; Potassium Channel; Renal tubule structure; Research Personnel; Role; Series; Sodium Channel; Structure; Structure-Activity Relationship; Techniques; Testing; Therapeutic; Tissues; Work; analog; cell type; combinatorial chemistry; counterscreen; design; follow-up; high throughput screening; in vivo; inhibitor/antagonist; insight; large-conductance calcium-activated potassium channels; molecular modeling; novel; patch clamp; public health relevance; research study; response; small molecule; therapeutic target; voltage

DESCRIPTION (provided by applicant): Inwardly rectifying potassium (Kir) channels are key regulators of diverse physiological processes and may represent novel drug targets for diseases. Their therapeutic potential has not been tested directly, however, due to the lack of drug-like compounds targeting inward rectifiers. The lack of selective "probes" has also hindered efforts to define the physiological functions of some Kir channels. To overcome this formidable barrier and create new opportunities for studying inward rectifier physiology, the investigators performed a high- throughput screen (HTS) of more than 200,000 compounds for small-molecule modulators of ROMK (Kir1.1), a putative target for a novel class of diuretic. One compound, termed VU590, inhibits ROMK at nanomolar concentrations and Kir7.1 in the low micromolar range, making it the first small-molecule inhibitor of both channels. The investigators went on to use medicinal chemistry to rationally design a nanomolar-affinity probe, termed VU591, which is highly selective for ROMK over more than 60 potential off targets, including inward rectifiers and BK channels. In Aim 1, the investigators will employ state-of-the-art molecular modeling techniques, atomic structure-guided mutagenesis and electrophysiology to define the VU590/591 binding sites in ROMK and Kir7.1. VU591 is remarkably selective for ROMK and therefore represents a promising candidate for further development for use in animal studies. In Aim 2, the investigators will first determine if VU591 is active in the native tissue by assessing its effects on K and Na transport in isolated perfused cortical collecting ducts under low- and high-flow conditions. The investigators also discovered a nanomolar-affinity inhibitor of a G-protein regulated inward rectifier (GIRK), a putative therapeutic target for atrial fibrillation. In Aim 3, the investigators will use medicinal chemistry, structure-guided mutagenesis and electrophysiology to define the molecular binding sites for this novel compound termed VU592. These studies will provide important new insights into the atomic structures of inward rectifiers and generate critically needed probes with which to define the integrative physiology and therapeutic potential of these channels. Lay summary: The investigators will combine medicinal chemistry, advanced computational techniques and classical physiological methods to develop drug-like compounds targeting potassium channels that could be therapeutic targets for hypertension, edema and cardiac arrhythmia. PUBLIC HEALTH RELEVANCE: Inward rectifying potassium (Kir) channels play key physiological roles in diverse cellular functions and may represent novel drug targets. However, the lack of selective pharmacological "probes" has hindered efforts to explore the integrative physiology and therapeutic potential of most Kir channels. Here we propose to employ medicinal chemistry, atomic structure-guided mutagenesis, kidney tubule microperfusion and electrophysiology to develop the small-molecule pharmacology for Kir1.1, Kir7.1 and Kir3 channels.

描述（由申请人提供）：内纠偏钾（Kir）通道是多种生理过程的关键调节因子，可能是疾病的新药物靶点。然而，由于缺乏针对内向整流器的类药物化合物，它们的治疗潜力尚未得到直接测试。选择性“探针”的缺乏也阻碍了对一些Kir通道生理功能的定义。为了克服这一巨大的障碍，并为研究内向整流生理学创造新的机会，研究人员对ROMK （Kir1.1）的小分子调节剂进行了超过20万种化合物的高通量筛选（HTS）， ROMK （Kir1.1）是一种新型利尿剂的假定靶点。其中一种化合物，称为VU590，在纳摩尔浓度下抑制ROMK，在低微摩尔范围内抑制Kir7.1，使其成为两个通道的第一个小分子抑制剂。研究人员继续使用药物化学合理地设计了一种纳米分子亲和探针，称为VU591，它对ROMK在60多个潜在的非靶标上具有高度选择性，包括向内整流器和BK通道。在Aim 1中，研究人员将采用最先进的分子建模技术、原子结构引导诱变和电生理学来定义ROMK和Kir7.1中的VU590/591结合位点。VU591对ROMK具有显著的选择性，因此具有进一步开发用于动物研究的前景。在Aim 2中，研究人员将首先通过评估VU591在低流量和高流量条件下对孤立灌注皮质集管中钾和钠运输的影响来确定VU591在天然组织中是否有活性。研究人员还发现了一种g蛋白调控内向整流器（GIRK）的纳米分子亲和抑制剂，这是一种假定的房颤治疗靶点。在第三阶段，研究人员将使用药物化学、结构引导诱变和电生理学来确定这种名为VU592的新化合物的分子结合位点。这些研究将为向内整流器的原子结构提供重要的新见解，并产生急需的探针，用于定义这些通道的综合生理学和治疗潜力。总结：研究人员将结合药物化学、先进的计算技术和经典的生理学方法来开发靶向钾通道的类药物化合物，这些化合物可能成为高血压、水肿和心律失常的治疗靶点。