A Pharmacologically Validated, High-Capacity, Functional Thallium Flux Assay for the Human Ether-a-go-go Related Gene Potassium Channel
A Pharmacologically Validated, High-Capacity, Functional Thallium Flux Assay for the Human Ether-a-go-go Related Gene Potassium Channel
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DOI：
10.1089/adt.2010.0351
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发表时间：
2010-12-01
影响因子：
1.8
通讯作者：
Garcia, Maria L.
中科院分区：
文献类型：
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作者：
Schmalhofer, William A.;Swensen, Andrew M.;Garcia, Maria L.
电压门控钾通道，人类 Ether-a-go-go 相关基因 (hERG)，代表 IKr 的分子成分，IKr 是参与心脏动作电位复极化的钾电流之一。 IKr 的抑制会增加心室动作电位的持续时间，表现为心电图中 QT 间期的延长，并增加潜在致命性室性心律失常的风险。由于 hERG 是 IKr 的合适替代品，因此可以在先导化合物识别和优化过程中识别化合物潜在安全隐患的 hERG 测定已被实施。尽管 hERG 评估的黄金标准是电生理学，但该技术即使使用目前可用的中等容量的自动化仪器，也无法满足支持制药环境中典型药物化学工作的通量需求。因此，需要能够在高容量模式下操作的同时提供可靠的分子药理学数据的测定。在本研究中，我们描述了满足这些标准的 hERG 通道的高容量 384 孔板和 1,536 孔板功能性铊通量测定。使用不同结构类别的 hERG 抑制剂对该测定进行了优化和验证。在铊通量测定和使用 QPatch 自动贴片平台的通道活动电生理记录中发现这些药物的效力之间存在极好的相关性。这项研究的扩展包括来自不同内部药物开发项目的 991 种药物化学化合物，表明铊通量测定是体外 hERG 活性的良好预测指标。这些数据表明 hERG 铊通量测定可以在支持药物开发工作中发挥重要作用。
The voltage-gated potassium channel, human Ether-a-go-go related gene (hERG), represents the molecular component of IKr, one of the potassium currents involved in cardiac action potential repolarization. Inhibition of IKr increases the duration of the ventricular action potential, reflected as a prolongation of the QT interval in the electrocardiogram, and increases the risk for potentially fatal ventricular arrhythmias. Because hERG is an appropriate surrogate for IKr, hERG assays that can identify potential safety liabilities of compounds during lead identification and optimization have been implemented. Although the gold standard for hERG evaluation is electrophysiology, this technique, even with the medium capacity, automated instruments that are currently available, does not meet the throughput demands for supporting typical medicinal chemistry efforts in the pharmaceutical environment. Assays that could provide reliable molecular pharmacology data, while operating in high capacity mode, are therefore desirable. In the present study, we describe a high-capacity, 384- and 1,536-well plate, functional thallium flux assay for the hERG channel that fulfills these criteria. This assay was optimized and validated using different structural classes of hERG inhibitors. An excellent correlation was found between the potency of these agents in the thallium flux assay and in electrophysiological recordings of channel activity using the QPatch automated patch platform. Extension of this study to include 991 medicinal chemistry compounds from different internal drug development programs indicated that the thallium flux assay was a good predictor of in vitro hERG activity. These data suggest that the hERG thallium flux assay can play an important role in supporting drug development efforts.