The activation of neuronal Kv7 channels has emerged as an important therapeutic strategy for epilepsy due to their role in regulating neuronal excitability. Retigabine (RTG), a Kv7.2/7.3 channel activator, was previously approved for epilepsy treatment but was withdrawn in 2017 because of its side effects of ophthalmological and dermatological pigmentation. Despite this setback, Kv7.2/7.3 channel remains a promising target for the development of antiepileptic drugs (AEDs). Previous studies have attributed the toxic metabolic quinone/azaquinone diimines and associated blue discoloration of RTG to its electron-rich tri-amine aromatic scaffold. A common strategy to mitigate this toxicity involves removing the ortho-aniline moiety of RTG. In this study, we designed and synthesized a series of compounds based on dimethylbenzene heterocyclic scaffolds as Kv7.2/7.3 activators. Among them, compound 2c demonstrated improved efficacy in Rb⁺ efflux assays and exhibited comparable activity in whole-cell patch clamp recordings on Kv7.2/7.3 channels. Moreover, compound 2c was effective in both maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol (sc-PTZ) mouse models, with ED₅₀ values of 4.02 mg/kg and 43.17 mg/kg, respectively. The LD₅₀ value of 2c in acute toxicity experiments was 340.35 mg/kg (95 % CI: 293.68-394.45) in mice. Additionally, 2c exhibited locomotor impairment with at TD₅₀ of 48.93 mg/kg in an open field test and 49.25 mg/kg in a rotarod test. Compound 2c also demonstrated reasonable pharmacokinetic (PK) properties and blood-brain barrier (BBB) penetration, along with good photostability. Site-directed mutagenesis, combined with molecular docking, confirmed that 2c interacted with key residues (W236, F305, and L299) in the Kv7.2 channel. Our findings suggest that compound 2c is a promising lead compound with a novel scaffold as a Kv7.2/7.3 activator for the management of epilepsy.

2025-06-30·FASEB JOURNAL

Regulation of Kv7 Channel Function in Rat Bladder by ERα and GPER1 Estrogen Receptors

Article

作者: Dworetzky, Steven ; Greenwood, Iain A. ; Wehbe, Zena ; Papaevangelou, Efthymia ; Lau, Skye

ABSTRACT:

This study investigated the sex and oestrous‐stage dependent effects on voltage‐gated potassium channels encoded by KCNQ genes (Kv7) channels in the rat bladder, focusing on the roles of different estrogen receptors (ERs). We hypothesized that ERα and G‐protein‐coupled estrogen receptor (GPER1) play distinct roles in modulating Kv7.4 and Kv7.5 channel functionality and localization. Using bladder tissues from male and female Wistar rats at different oestrous stages, we performed myography, RT‐qPCR, immunocytochemistry, and western blot analyses. Our results showed that ML213, a Kv7.2–7.5 activator, was more effective in male bladders, correlating with higher membrane localization of Kv7.4 and Kv7.5. In contrast, female rats in the proestrous and oestrous stages exhibited reduced sensitivity to ML213, associated with decreased Kv7.5 membrane abundance. In this group, ERα attenuated both the Kv7 functional response to ML213 and the membrane localization of Kv7.5, whereas GPER1 was associated with reducing the membrane abundance of the channel without affecting functionality. In diestrous and metestrous rat bladders, ERα was not active in baseline conditions. Instead, GPER1 induced a removal of Kv7.5 from the membrane, without exerting any effect on the Kv7 functional response to ML213. These findings highlight a complex interplay between sex hormones and ERs in bladder smooth muscle cells, offering insights into sex‐specific differences in bladder function and potential therapeutic targets for bladder disorders.

2025-04-01·JOURNAL OF MEDICAL GENETICS

Genetic features and pharmacological rescue of novel Kv7.2 variants in patients with epilepsy

Article

作者: Zhang, Yi ; Yu, Shihui ; Zhang, Jiahui ; Meng, Yuhuan ; Zhang, Xue ; Mao, Di ; Song, Huilin ; Qiao, Shupei ; Sui, Shengbin ; Cao, Tianhua ; Xia, Yang ; Song, Yue ; Xie, Li ; Meng, Lingdi ; Jia, Ying ; Jing, Wenwen ; Peng, Ziyue

Background:

Increasing evidence indicates a robust correlation between epilepsy and variants of the Kv7.2 ( KCNQ2 ) channel, which is critically involved in directing M-currents and regulating neuronal excitability within the nervous system. With the advancement of next-generation sequencing, the identification of KCNQ2 variants has surged. Nonetheless, their functional impacts are still being determined, introducing uncertainty into the diagnostic process for affected families and potentially hindering their ability to participate in targeted precision medicine trials. This study aims to elucidate the pathogenicity of these novel variants and explore potential therapeutic interventions.

Methods:

Whole-cell patch-clamp recordings, western blotting, and immunofluorescent staining were performed to elucidate the functional consequences of the identified variants. Moreover, coimmunoprecipitation techniques were conducted to explore protein interactions, thus facilitating a deeper understanding of the underlying pathogenetic mechanisms contributing to the disease. Ultimately, the effects of pharmacological interventions were evaluated in vitro using the patch-clamp technique.

Results:

Herein, we identified 12 novel KCNQ2 variants, further expanding the mutational spectrum of KCNQ2 . Our investigation revealed that one gain-of-function variant (p.L102V (c.304C>G)) and three loss-of-function variants (p.H328Q (c.984C>G), p.A336V (c.1007C>T) and p.D563Efs*22 (c.1688_1689insACTT)) had different impacts on the binding of calmodulin and phosphati-dylinositol-4,5-bisphosphate, potentially altering their localisation and protein stability. Furthermore, the application of ML213, unlike Retigabine and ICA-069673, led to a significant increase in the current of p.H328Q.

Conclusion:

This study expanded the mutational spectrum of KCNQ2 and analysed the genetic and functional consequences, as well as the pharmacological rescue, of four de novo KCNQ2 variants. These findings offer valuable insights into the precise medicine of KCNQ2 -related epilepsy.

100 项与 ML213 相关的药物交易

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