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)、慢性肾病的常见且危及生命的后果 （CKD）和慢性肝病通常使用袢利尿剂作为快速减少液体的一线疗法。 心力衰竭、慢性肾病和肝衰竭患者的容量负担此类利尿剂通过抑制氯化钠重吸收起作用。 在亨利氏襻的粗升肢 (TAL) 中增加 NaCl 向远端回旋的输送 包括远端肾单位的肾小管 (DCT) 和皮质集合管 (CCD) 响应增加的 NaCl。 负载时，DCT 和 CCD 通过远端小管重塑增加其 NaCl 重吸收能力，涉及 细胞/组织肥大以及通过上调涉及 NaCl 的离子转运蛋白和通道的表达 这种补偿机制降低了袢利尿剂的有效性并引起袢。 利尿抵抗，这是治疗心衰、慢性肾病和肝衰竭的常见临床问题。 共识是远端作用的利尿剂抑制 DCT 中钠 (Na+) 的重吸收（即噻嗪类利尿剂） 或 TAL 下游的 CCD（即阿米洛利）应给予克服袢利尿剂抵抗。 然而，这两种利尿剂都有严重的缺点，突出表明需要更有效、更安全和新颖的利尿剂。 机制 远端肾单位靶向利尿剂 异聚 Kir4.1/5.1 内向整流钾 (Kir) 通道。 在过去的十年中，它们已成为潜在的远端肾单位利尿靶标，原因有两个：首先，这些。 基底外侧膜通道在 DCT 和 CCD 中表达，对于 Na+ 重吸收至关重要 其次，也是重要的是，Kir4.1/5.1 患者的功能丧失。 SeSAME/EAST 综合征导致肾性盐消耗和低血压，提供了强大的遗传因素 我们最近进行了一项 NIH 资助的对 Kir4.1/5.1 作为人体利尿靶点的验证。 （R01DK120821；Denton PI）来自范德比尔特研究所的 80,475 种化合物的高通量筛选 (HTS) 化学生物学发现集合并鉴定了数百种结构多样的小分子抑制剂 Kir4.1/5.1 的开发采用迭代药物化学和功能分析。 一流、中等效力 (IC50 = 0.24 µM)、高选择性（9 个相关 Kir 通道 >30 倍）、体外 Kir4.1/5.1 的抑制剂，命名为 VU6036720 (PMID 35246480)，但不幸的是，VU6036720 未能成功。 由于高血浆蛋白结合和快速代谢清除，在小鼠中诱导利尿反应。 在此后续应用中，我们建议采用药物化学和已建立的功能测定法来 进一步优化效力、选择性以及药物代谢和药代动力学 (DMPK) 特性 VU6036720 和我们的 HTS 活动中确定的其他备用支架在目标 2 中，我们将评估体内。 优化抑制剂在利尿剂抵抗和 CKD 小鼠模型中的活性 完成该计划将。 提供 Kir4.1/5.1 作为可行的利尿剂目标的临床前验证，一般来说，并用于规避 特别是与利尿抵抗相关的并发症。