ACTA PHARMACOLOGICA SINICA
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2025
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IF 8.4
Guo Qing,Gan Jun,Wang En-ze,Wei Yu-ming,Xu Jie,Xu Yun,Zhang Fei-fei,Cui Meng,Jia Meng-xing,Kong Ming-jian,Tang Qiong-yao,Zhang Zhe
Patients suffering epilepsy caused by the gain-of-function mutants of the hKCNT1 potassium channels are drug refractory. In this study, we cloned a novel human KCNT1B channel isoform using the brain cDNA library and conducted patch-clamp and molecular docking analyses to characterize the pharmacological properties of the hKCNT1B channel using thirteen drugs. Among cinchona alkaloids, we found that hydroquinine exerted the strongest blocking effect on the hKCNT1B channel, especially the F313L mutant. In addition, we confirmed the antitussive drug tipepidine was also a potent inhibitor of the hKCNT1B channel. Subsequently, we proved that these two drugs produced an excellent therapeutic effect on the epileptic model of KCNT1 Y777H mutant male mice; thus, both could be ready-to-use anti-epileptic drugs. On the other hand, we demonstrated that the activation of the KCNT1 channel by loxapine and clozapine was through interacting with pore domain residues to reverse the run-down of the KCNT1 channel. Taken together, our results provide new insights into the mechanism of the modulators in regulating the KCNT1 channel activity as well as important candidates for clinical tests in the treatment of KCNT1 mutant-associated epilepsy.
研究领域:
神经生物学
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药理学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BRITISH JOURNAL OF PHARMACOLOGY
·
2024
·
IF 6.8
Chang Di,Tong Wu,Kai Gao,Na Li,Huifang Song,Lili Wang,Haojie Sun,Jingyun Yi,Xinran Zhang,Jiexin Chen,Mala Shah,Yuwu Jiang,Zhuo Huang
Background and Purpose KCNT1 encodes a sodium-activated potassium channel (Slack channel), and its mutation can cause several forms of epilepsy. Traditional antiepileptic medications have limited efficacy in treating patients with KCNT1 mutations. Here, we describe one heterozygous KCNT1 mutation, M267T, in a patient with EIMFS. The pathological channel properties of this mutation and its effect on neuronal excitability were investigated. Additionally, this study aimed to develop a medication for effective prevention of KCNT1 mutation-induced seizures. Experimental Approach Wild-type or mutant KCNT1 plasmids were expressed heterologously in Xenopus laevis oocytes, and channel property assessment and drug screening were performed based on two-electrode voltage-clamp recordings. The single-channel properties were investigated using the excised inside-out patches from HEK293T cells. Through in utero electroporation, WT and M267T Slack channels were expressed in the hippocampal CA1 pyramidal neurons in male mice, followed by the examination of the electrical properties using the whole-cell current-clamp technique. The kainic acid-induced epilepsy model in male mice was used to evalute the antiseizure effects of carvedilol. Key Results The KCNT1 M267T mutation enhanced Slack channel function by increasing single-channel open probability. Through screening 16 FDA-approved ion channel blockers, we found that carvedilol effectively reversed the mutation-induced gain-of-function channel properties. Notably, the KCNT1 M267T mutation in the mouse hippocampal CA1 pyramidal neurons affected afterhyperpolarization properties and induced neuronal hyperexcitability, which was inhibited by carvedilol. Additionally, carvedilol exhibited antiseizure effects in the kainic acid-induced epilepsy model. Conclusion and Implication Our findings suggest carvedilol as a new potential candidate for treatment of epilepsies. Graphical
研究领域:
神经科学
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药理学
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分子生物学
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医学遗传学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
eLife
·
2024
·
IF 6.4
Tian Yuan,Yifan Wang,Yuchen Jin,Hui Yang,Shuai Xu,Heng Zhang,Qian Chen,Na Li,Xinyue Ma,Huifang Song,Chao Peng,Ze Geng,Jie Dong,Guifang Duan,Qi Sun,Yang Yang,Fan Yang,Zhuo Huang
Quinidine has been used as an anticonvulsant to treat patients with KCNT1-related epilepsy by targeting gain-of-function KCNT1 pathogenic mutant variants. However, the detailed mechanism underlying quinidine’s blockade against KCNT1 (Slack) remains elusive. Here, we report a functional and physical coupling of the voltage-gated sodium channel NaV1.6 and Slack. NaV1.6 binds to and highly sensitizes Slack to quinidine blockade. Homozygous knockout of NaV1.6 reduces the sensitivity of native sodium-activated potassium currents to quinidine blockade. NaV1.6-mediated sensitization requires the involvement of NaV1.6’s N- and C-termini binding to Slack’s C-terminus and is enhanced by transient sodium influx through NaV1.6. Moreover, disrupting the Slack-NaV1.6 interaction by viral expression of Slack’s C-terminus can protect against SlackG269S-induced seizures in mice. These insights about a Slack-NaV1.6 complex challenge the traditional view of ‘Slack as an isolated target’ for anti-epileptic drug discovery efforts and can guide the development of innovative therapeutic strategies for KCNT1-related epilepsy.
研究领域:
神经科学
·
药理学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
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