Triazolothienopyrimidine Inhibitors of Urea Transporter UT-B Reduce Urine Concentration
Triazolothienopyrimidine Inhibitors of Urea Transporter UT-B Reduce Urine Concentration
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DOI：
10.1681/asn.2011070751
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发表时间：
2012-07-01
影响因子：
13.6
通讯作者：
Verkman, A. S.
中科院分区：
文献类型：
--
作者：
Yao, Chenjuan;Anderson, Marc O.;Verkman, A. S.
尿素转运蛋白（UT）促进肾脏对尿液的浓缩，表明抑制这些蛋白可能具有利尿策略的治疗作用。我们筛选了10万种化合物用于UT-B抑制使用基于低渗裂解的乙酰胺负载小鼠红细胞的光学分析。我们鉴定了一类三唑噻吩嘧啶UT-B抑制剂；最有效的化合物UTBinh-14对人和小鼠UT-B的IC50值分别为10 nM和25 nM，完全可逆地抑制尿素运输。UTBinh-14在UT-B蛋白的胞内位点与尿素结合竞争。UTBinh-14对UT-B具有低毒性和高选择性。在小鼠腹腔注射UTBinh-14以达到肾脏中预测的治疗浓度后，1-脱氨基-8- d -精氨酸-抗利尿素后，UTBinh-14处理小鼠的尿液渗透压比对照组小鼠低约700 mosm/kg H2O。在自由饮水的小鼠中，UTBinh-14也增加了尿量并降低了尿渗透压。UTBinh-14不降低UT-B敲除小鼠的尿渗透压。总之，这些数据为UT抑制剂在高抗利尿激素、液体潴留条件下降低尿浓度的潜在效用提供了概念证明。UT抑制剂的利尿机制可能补充了传统利尿剂的作用，其目标是钠的运输。
Urea transport (UT) proteins facilitate the concentration of urine by the kidney, suggesting that inhibition of these proteins could have therapeutic use as a diuretic strategy. We screened 100,000 compounds for UT-B inhibition using an optical assay based on the hypotonic lysis of acetamide-loaded mouse erythrocytes. We identified a class of triazolothienopyrimidine UT-B inhibitors; the most potent compound, UTBinh-14, fully and reversibly inhibited urea transport with IC50 values of 10 nM and 25 nM for human and mouse UT-B, respectively. UTBinh-14 competed with urea binding at an intracellular site on the UT-B protein. UTBinh-14 exhibited low toxicity and high selectivity for UT-B over UT-A isoforms. After intraperitoneal administration of UTBinh-14 in mice to achieve predicted therapeutic concentrations in the kidney, urine osmolality after administration of 1-deamino-8-D-arginine-vasopressin was approximately 700 mosm/kg H2O lower in UTBinh-14 treated mice than vehicle-treated mice. UTBinh-14 also increased urine output and reduced urine osmolality in mice given free access to water. UTBinh-14 did not reduce urine osmolality in UT-B knockout mice. In summary, these data provide proof of concept for the potential utility of UT inhibitors to reduce urinary concentration in high-vasopressin, fluid-retaining conditions. The diuretic mechanism of UT inhibitors may complement the action of conventional diuretics, which target sodium transport.