Functional evaluation of a rat model of KCNT1-related epilepsy

Nana Liu; Zehong Lin; Huifang Song; Aojie Cai; Xiao Li; Junjiao Zhang; Di Chang; Taoyun Ji; Ye Wu; Zhuo Huang; Yuwu Jiang; Kai Gao

doi:10.1016/j.eplepsyres.2025.107589

Functional evaluation of a rat model of KCNT1-related epilepsy

Epilepsy Res. 2025 May 17:216:107589. doi: 10.1016/j.eplepsyres.2025.107589. Online ahead of print.

Authors

Nana Liu¹, Zehong Lin², Huifang Song³, Aojie Cai⁴, Xiao Li¹, Junjiao Zhang¹, Di Chang³, Taoyun Ji⁵, Ye Wu⁵, Zhuo Huang⁶, Yuwu Jiang⁷, Kai Gao⁸

Affiliations

¹ Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China.
² Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China; Department of Child Health Care, Children's Hospital, Capital Institute of Pediatrics, Beijing 100020, China.
³ Department of Molecular and Cellular Pharmacology, Peking University Health Science Center, Beijing 100191, China.
⁴ Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China; Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou City, Henan Province 450000, China.
⁵ Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China; Children Epilepsy Center, Peking University First Hospital, Beijing 100034, China.
⁶ Department of Molecular and Cellular Pharmacology, Peking University Health Science Center, Beijing 100191, China; State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China.
⁷ Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China; Children Epilepsy Center, Peking University First Hospital, Beijing 100034, China; Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100871, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing 100069, China. Electronic address: jiangyuwu@bjmu.edu.cn.
⁸ Department of Pediatrics, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Peking University First Hospital, Beijing 100034, China; Children Epilepsy Center, Peking University First Hospital, Beijing 100034, China. Electronic address: gaokaipku@bjmu.edu.cn.

PMID: 40460702
DOI: 10.1016/j.eplepsyres.2025.107589

Abstract

Objective: KCNT1 encodes a sodium-activated potassium channel, and its variant can lead to refractory epilepsy. The resistance to antiseizure medication in KCNT1 variant-related epilepsy suggests the presence of complex gene regulation. Our goal is to clarify the pathogenicity of a KCNT1 variant associated with epilepsy.

Methods: Here, we intended to characterize the pathogenicity of the Kcnt1-269 variant (c.805 G > A, c.807 G > C, p.G269S; corresponding to c.862 G > A, p.G288S in human) in vitro and in vivo, and to analyze the transcriptome of the rat cerebral cortex through RNA sequencing.

Results: Our study revealed that homozygous Kcnt1-269 variant rats showed excessive neuroexcitability in CA1 pyramidal neurons, including enhanced neuronal action potential amplitudes, decreased action potential thresholds, and increased neuronal firing numbers. Homozygous and heterozygous Kcnt1-269 variant rats had high frequency of evoked action potential under different step currents. The cumulative dose of pentetrazol required to induce epileptic seizures in homozygous Kcnt1-269 variant rats was significantly lower compared with wild-type rats. Transcriptome analysis of the cerebral cortex identified 190 upregulated and 149 downregulated genes in heterozygous Kcnt1-269 variant rats compared with wild-type rats. Functional enrichment analysis revealed that "nucleolus," "neuropeptide signaling pathway," "dendrite," and "protein binding" were the most prominent Gene Ontology terms, while "neuroactive ligand-receptor interaction" was one of the most significant Kyoto Encyclopedia of Genes and Genomes terms.

Conclusion: Our findings elucidate the epileptogenicity of the Kcnt1-269 variant in rats and may provide new insights into the pathways associated with Kcnt1 variant-related epilepsy through transcriptome analysis.

Keywords: Epilepsy; Kcnt1; Neuroexcitability; RNA-sequencing.