Kasahara Yoichi, Sakurai Takanobu, Matsuda Ryusei, Narukawa Masataka, Yasuoka Akihito, Mori Naoki, Watanabe Hidenori, Okabe Takayoshi, Kojima Hirotatsu, Abe Keiko, Misaka Takumi, Asakura Tomiko
a Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences , The University of Tokyo , Tokyo , Japan.
b Drug Discovery Initiative (DDI) , The University of Tokyo , Tokyo , Japan.
Biosci Biotechnol Biochem. 2019 Feb;83(2):243-250. doi: 10.1080/09168451.2018.1533802. Epub 2018 Oct 21.
The epithelial sodium channel (ENaC) plays a pivotal role in sodium homeostasis, and the development of drugs that modulate ENaC activity is of great potential therapeutic relevance. We screened 6100 chemicals for their ability to activate sodium permeability of ENaC. We used a two-step strategy: a high throughput cell-based assay and an electrophysiological assay. Five compounds were identified showing common structural features including an indole or benzothiophene ring. ENaC consists of three subunits: α, β, and γ. Changing the heteromeric combination of human and mouse ENaC αβγ subunits, we found that all five compounds activated the human β subunit but not the mouse subunit. However, four of them exhibited lower activity when the human γ subunit was substituted by the mouse γ subunit. Our findings provide a structural basis for designing human ENaC activity modulators. Abbreviations: ENaC: Epithelial sodium channel; ΔRFU: delta relative fluorescence units; EC: Half-maximal effective concentration; E: maximum effect value.
上皮钠通道（ENaC）在钠稳态中起关键作用，开发调节ENaC活性的药物具有巨大的潜在治疗意义。我们筛选了6100种化学物质激活ENaC钠通透性的能力。我们采用了两步策略：基于细胞的高通量检测和电生理检测。鉴定出了5种具有共同结构特征的化合物，包括吲哚或苯并噻吩环。ENaC由三个亚基组成：α、β和γ。改变人和小鼠ENaCαβγ亚基的异源组合，我们发现所有5种化合物均激活人β亚基而非小鼠亚基。然而，当人γ亚基被小鼠γ亚基取代时，其中4种化合物表现出较低的活性。我们的研究结果为设计人ENaC活性调节剂提供了结构基础。缩写：ENaC：上皮钠通道；ΔRFU：相对荧光单位变化值；EC：半数最大效应浓度；E：最大效应值。
