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.

总结 水肿是充血性心力衰竭（HF）、慢性肾脏疾病（CHF） (CKD)和慢性肝病。袢利尿剂通常作为一线治疗，以快速减少液体 HF、CKD和肝功能衰竭患者的容量负荷。这类利尿剂通过抑制氯化钠重吸收发挥作用 在Henle袢的粗升支（TAL）中增加NaCl向远曲的输送 肾小管（DCT）和皮质集合管（CCD）组成的远端肾单位。为了应对增加的NaCl 负荷时，DCT和CCD通过远端小管重塑增加其NaCl重吸收能力， 细胞/组织肥大，并通过上调离子转运蛋白和通道的表达参与NaCl 重吸收这种代偿机制降低了袢利尿剂的有效性，并引起袢 利尿剂抵抗，这是HF、CKD和肝衰竭治疗中的常见临床问题。越来越 共识是抑制DCT中钠（Na+）重吸收的远端作用利尿剂（即，噻嗪类利尿剂） 或CCD（即，阿米洛利）下游的TAL应给予克服袢利尿剂抵抗。 然而，这两类利尿剂都有严重的缺点，突出了对更有效，更安全和新颖的需求- 机制远端肾单位靶向利尿剂。异聚Kir4.1/5.1内向整流钾通道 在过去十年中，由于两个主要原因，已成为潜在的远端肾单位利尿剂靶点。一是这些 基底外侧膜通道在DCT和CCD中表达，并且对于在结肠中的Na+重吸收是必需的。 两个肾单位节段。第二，重要的是，在患有糖尿病的患者中Kir4.1/5.1功能的丧失， SEEAST/EAST综合征会导致肾性盐耗和低血压， Kir4.1/5.1作为人类利尿靶点的验证。我们最近做了一个NIH资助的 （R 01 DK 120821;丹顿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）。 化学生物学发现收集并确定了数百种结构多样的小分子抑制剂 Kir4.1/5.1。我们采用迭代的药物化学和功能分析来推动 一流的，中等效力（IC 50 = 0.24 µM），高选择性（超过9个相关Kir通道的30倍），体外 Kir4.1/5.1抑制剂，命名为VU 6036720（PMID 35246480）。然而，不幸的是，VU 6036720未能 由于高血浆蛋白结合和快速代谢清除而在小鼠中诱导利尿反应。目标1 在这一后续应用中，我们建议采用药物化学和已建立的功能测定， 进一步优化的效力，选择性，和药物代谢和药代动力学（DMPK）的性质， VU 6036720和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 优化的抑制剂在利尿剂抵抗和CKD小鼠模型中的活性。该计划的完成将 提供Kir4.1/5.1作为可行的利尿靶点的临床前验证，一般情况下， 特别是与利尿剂抵抗相关的并发症