Preclinical validation of Kir4.1/5.1 inhibitors for overcoming diuretic resistance

Kir4.1/5.1 抑制剂克服利尿剂抵抗的临床前验证

• 批准号: 10740429
• 负责人: Jerod S. Denton
• 金额: $ 49.67万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10740429
• 关键词: Abdomen; Affect; American; Amiloride; Animals; Binding Proteins; Biological Assay; Biology; Cells; Chemicals; Chronic Kidney Failure; Clinical; Clinical Treatment; Collection; Congestive Heart Failure; Consensus; Databases; Development; Disadvantaged; Disease; Distal; Distal convoluted renal tubule structure; Diuretics; Dose; Drug Kinetics; Drug Targeting; Duct (organ) structure; Edema; Effectiveness; Electrophysiology (science); Extracellular Fluid; Fluid Balance; Freedom; Funding; Genetic; Goals; Grant; Heart failure; Human; Hypertension; Hypertrophy; Hypotension; In Vitro; Industry Standard; Investigational Drugs; Ion Channel; Ions; Kidney; Laboratories; Legal patent; Licensing; Life; Limb structure; Liquid substance; Liver Failure; Lung; Measures; Mediating; Metabolic; Molecular; Mus; Names; Nephrons; Oral; Paper; Patients; Pharmaceutical Chemistry; Pharmacologic Substance; Pharmacology; Phenotype; Physiology; Plasma; Plasma Proteins; Positioning Attribute; Potassium; Potassium Channel; Property; Publishing; Renal function; Resistance; Risk; SeSAME syndrome; Series; Sesame - dietary; Small Business Innovation Research Grant; Sodium; Sodium Chloride; Structure of ascending limb of Henle' s loop; Symptoms; Testing; Thiazide Diuretics; Thick; Tissue Expansion; Tissues; United States National Institutes of Health; Urine; Validation; Work; absorption; analog; basolateral membrane; biopharmaceutical industry; chronic liver disease; cost; drug metabolism; efficacy evaluation; efficacy study; equilibration disorder; experience; follow-up; high reward; high risk; high throughput screening; in vivo; inhibitor; intraperitoneal; knowledge translation; lead optimization; loss of function mutation; meetings; meter; mouse model; novel; patch clamp; patient population; pre-clinical; programs; response; scaffold; small molecule inhibitor; thiazide; timeline; wasting

SUMMARY Edema is a common, life-threatening consequence of congestive heart failure (HF), chronic kidney disease (CKD), and chronic liver disease. Loop diuretics are often used as a first-line therapy to quickly reduce the fluid volume burden in HF, CKD, and liver failure patients. This class of diuretic works by inhibiting NaCl reabsorption in the thick ascending limb (TAL) of Henle’s loop and increasing the delivery of NaCl to the distal convoluted tubule (DCT) and cortical collecting duct (CCD) comprising the distal nephron. In response to the increased NaCl load, the DCT and CCD increase their NaCl reabsorption capacity through distal tubule remodeling involving cell/tissue hypertrophy and by upregulating the expression of ion transporters and channels involved in NaCl reabsorption. This compensatory mechanism diminishes the effectiveness of loop diuretics and gives rise to loop diuretic resistance, which is a common clinical problem in the treatment of HF, CKD, and liver failure. A growing consensus is that distally acting diuretics that inhibit sodium (Na+) reabsorption in the DCT (i.e., thiazide diuretics) or CCD (i.e., amiloride) downstream of the TAL should be administered to overcome loop diuretic resistance. However, both diuretic classes have serious liabilities that highlight the need for more effective, safer, and novel- mechanism distal nephron-targeted diuretics. Heteromeric Kir4.1/5.1 inward rectifier potassium (Kir) channels have emerged over the last decade as potential distal nephron diuretic targets for two main reasons. First, these basolateral membrane channels are expressed in the DCT and CCD and are essential for Na+ reabsorption in both nephron segments. Secondly, and importantly, the loss of Kir4.1/5.1 function in patients with SeSAME/EAST syndrome leads to renal salt wasting and low blood pressure, providing strong genetic validation for Kir4.1/5.1 as a diuretic target in humans. We recently performed an NIH-funded (R01DK120821; Denton PI) high-throughput screen (HTS) of 80,475 compounds from the Vanderbilt Institute of Chemical Biology Discovery Collection and identified hundreds of structurally diverse small-molecule inhibitors of Kir4.1/5.1. We employed iterative medicinal chemistry and functional analysis to drive the development of the first-in-class, moderately potent (IC50 = 0.24 µM), highly selective (>30 fold over 9 related Kir channels), in vitro inhibitor of Kir4.1/5.1, named VU6036720 (PMID 35246480). Unfortunately, however, VU6036720 failed to induce a diuretic response in mice due to high plasma protein binding and rapid metabolic clearance. In Aim 1 of this follow-up application, we propose to employ medicinal chemistry and established functional assays to further optimize the potency, selectivity, and drug metabolism and pharmacokinetic (DMPK) properties of VU6036720 and other backup scaffolds identified in our HTS campaign. In Aim 2, we will evaluate the in vivo activity of optimized inhibitors in mouse models of diuretic resistance and CKD. Completion of this program will provide pre-clinical validation of Kir4.1/5.1 as a viable diuretic target, generally, and for circumventing complications associated with diuretic resistance, specifically.

概括 水肿是充血性心力衰竭（HF），慢性肾脏疾病的常见，威胁生命的结果 （CKD）和慢性肝病。循环利尿剂通常被用作一线疗法，以快速减少液体 HF，​​CKD和肝衰竭患者的体积燃烧。这类利尿作品通过抑制NaCl的重吸收 在亨尔循环的较厚的升肢（tal）中，并增加了NaCl向远端的递送 Tubele（DCT）和皮层收集管（CCD）完成远端肾单位。响应增加的NaCl 负载，DCT和CCD通过远端小管重塑涉及的NaCl重吸收能力 细胞/组织肥大并通过上调与NaCl的离子转运蛋白和通道的表达 重吸收。这种补偿机制降低了循环利尿剂的有效性，并引起循环 利尿剂耐药性，这是HF，CKD和肝衰竭治疗的常见临床问题。成长 共识是分别作用于抑制DCT中钠（Na+）重吸收的利尿剂（即噻嗪类利尿剂） 应管理TAL的下游的CCD（即淀粉样板），以克服循环利尿剂耐药性。 但是，两种利尿类别都有严重的责任，强调需要更有效，安全和新颖 机理远端nephron靶向利尿剂。杂体KIR4.1/5.1内整流钾（KIR）通道 在过去的十年中，由于两个主要原因而出现了作为潜在的肾小管利尿剂靶标。首先，这些 基底外侧膜通道在DCT和CCD中表示，对于Na+重吸收至关重要 两个肾单位段。其次，重要的是，患者的Kir4.1/5.1功能丧失 芝麻/东综合症会导致肾盐浪费和低血压，提供强大的遗传 Kir4.1/5.1作为人类利尿目标的验证。我们最近进行了NIH资助 （R01DK120821; Denton PI）来自Vanderbilt Institute的80,475种化合物的高通量屏幕（HTS） 化学生物学发现收集并确定了数百种结构上多样的小分子抑制剂 Kir4.1/5.1的我们采用迭代医学化学和功能分析来推动 一流的，中等潜力（IC50 = 0.24 µm），高度选择性（在9个相关KIR通道上> 30倍），体外 Kir4.1/5.1的抑制剂，称为VU6036720（PMID 35246480）。但是不幸的是，VU6036720未能 由于高血浆蛋白结合和快速代谢清除率，引起小鼠的利尿剂反应。在目标1中 在此后续应用中，我们建议对员工医学化学和建立功能测定 进一步优化效力，选择性和药物代谢和药代动力学（DMPK）特性 VU6036720和其他HTS运动中确定的其他备用脚手架。在AIM 2中，我们将评估体内 利尿剂耐药性和CKD小鼠模型中优化抑制剂的活性。该程序的完成将 通常提供Kir4.1/5.1的临床前验证，通常是可行的利尿目标 特别是与利尿剂抗性相关的并发症。