Malignant migrating partial seizure of infancy (MMPSI) is a devastating and pharmacoresistant form of infantile epilepsy. MMPSI has been linked to multiple gain-of-function (GOF) mutations in the KCNT1 gene, which encodes for a potassium channel often referred to as SLACK. SLACK channels are sodium-activated potassium channels distributed throughout the central nervous system (CNS) and the periphery. The investigation described here aims to discover SLACK channel inhibitor tool compounds and profile their pharmacokinetic and pharmacodynamic properties. A SLACK channel inhibitor VU0531245 (VU245) was identified via a high-throughput screen (HTS) campaign. Structure-activity relationship (SAR) studies were conducted in five distinct regions of the hit VU245. VU245 analogs were evaluated for their ability to affect SLACK channel activity using a thallium flux assay in HEK-293 cells stably expressing wild-type (WT) human SLACK. Selected analogs were tested for metabolic stability in mouse liver microsomes and plasma-protein binding in mouse plasma. The same set of analogs was tested via thallium flux for activity versus human A934T SLACK and other structurally related potassium channels, including SLICK and Maxi-K. In addition, potencies for selected VU245 analogs were obtained using whole-cell electrophysiology (EP) assays in CHO cells stably expressing WT human SLACK through an automated patch clamp system. Results revealed that this scaffold tolerates structural changes in some regions, with some analogs demonstrating improved SLACK inhibitory activity, good selectivity against the other channels tested, and modest improvements in metabolic clearance. Analog VU0935685 represents a new, structurally distinct small-molecule inhibitor of SLACK channels that can serve as an in vitro tool for studying this target.

婴儿恶性迁移性部分发作 （MMPSI） 是一种具有破坏性和耐药性的婴儿癫痫。MMPSI 与 KCNT1 基因中的多种功能获得性 （GOF） 突变有关，KCNT1 基因编码通常称为 SLACK 的钾通道。SLACK 通道是分布在整个中枢神经系统 （CNS） 和外周的钠激活钾通道。此处描述的研究旨在发现 SLACK 通道抑制剂工具化合物并分析其药代动力学和药效学特性。通过高通量筛选 （HTS） 活动鉴定了 SLACK 通道抑制剂 VU0531245 （VU245）。构效关系 （SAR） 研究在命中 VU245 的五个不同区域进行。使用铊通量测定法在稳定表达野生型 （WT） 人 SLACK 的 HEK-293 细胞中评估 VU245 类似物影响 SLACK 通道活性的能力。测试了选定的类似物在小鼠肝脏微粒体中的代谢稳定性和在小鼠血浆中的血浆蛋白结合。通过铊通量测试了同一组类似物与人 A934T SLACK 和其他结构相关的钾通道（包括 SLICK 和 Maxi-K）的活性。此外，通过自动膜片钳系统在稳定表达 WT 人 SLACK 的 CHO 细胞中使用全细胞电生理学 （EP） 测定获得选定 VU245 类似物的效力。结果显示，该支架可耐受某些区域的结构变化，一些类似物显示出改进的 SLACK 抑制活性、对其他测试通道的良好选择性以及代谢清除率的适度改善。 Analog VU0935685 代表了一种新的、结构独特的 SLACK 通道小分子抑制剂，可以作为研究该靶标的体外工具。