Functional characterization and in vitro pharmacological rescue of KCNQ2 pore mutations associated with epileptic encephalopathy  

作　　者：Gui-mei Yang Fu-yun Tian Yan-wen Shen Chuan-yan Yang Hui Yuan Ping Li Zhao-bing Gao 

机构地区：[1]School of Pharmacy,Zunyi Medical University,Zunyi,563000,China [2]Zhongshan Institute for Drug Discovery,Shanghai Institute of Materia Medica,Chinese Academy of Sciences,Zhongshan,528400,China [3]Center for Neurological and Psychiatric Research and Drug Discovery,Shanghai Institute of Materia Medica,Chinese Academy of Sciences,Shanghai,201203,China [4]Department of Pediatrics,The First Medical Center of PLA General Hospital,Beijing,100853,China [5]Department of Pediatric neurology,Children’s Hospital of Fudan university at Xiamen,Xiamen,361006,China [6]School of Basic Medicine and Clinical Pharmacy,China Pharmaceutical University,Nanjing,211198,China [7]School of Pharmaceutical Sciences,Southern Medical University,Guangzhou,510515,China

出　　处：《Acta Pharmacologica Sinica》2023年第8期1589-1599,共11页中国药理学报（英文版）

基　　金：funding from the High-level New R&D Institute (2019B090904008);the High-level Innovative Research Institute (2021B0909050003)of the Department of Science and Technology of Guangdong Province;National Science and Technology Innovation 2030 Major Program (2021ZD0200900);Shanghai Municipal Science and Technology Major Project (2018SHZDZX05);Zhongshan Municipal Bureau of Science and Technology (CXTD2022013);the National Science Fund for Distinguished Young Scholars (81825021);PL received funding from the National Natural Science Foundation of China (32100621 and 82273913);Guangdong Basic and Applied Basic Research Foundation (2022A1515010851);Zhongshan Municipal Bureau of Science and Technology (220418134367984);FYT received funding from Zhongshan Municipal Bureau of Science and Technology (210724194041939).

摘　　要：Mutations in the KCNQ2 gene encoding KV7.2 subunit that mediates neuronal M-current cause a severe form of developmental and epileptic encephalopathy(DEE).Electrophysiological evaluation of KCNQ2 mutations has been proved clinically useful in improving outcome prediction and choosing rational anti-seizure medications(ASMs).In this study we described the clinical characteristics,electrophysiological phenotypes and the in vitro response to KCNQ openers of five KCNQ2 pore mutations(V250A,N258Y,H260P,A265T and G290S)from seven patients diagnosed with KCNQ2-DEE.The KCNQ2 variants were transfected into Chinese hamster ovary(CHO)cells alone,in combination with KCNQ3(1:1)or with wild-type KCNQ2(KCNQ2-WT)and KCNQ3 in a ratio of 1:1:2,respectively.Their expression and electrophysiological function were assessed.When transfected alone or in combination with KCNQ3,none of these mutations affected the membrane expression of KCNQ2,but most failed to induce a potassium current except A265T,in which trace currents were observed when co-transfected with KCNQ3.When co-expressed with KCNQ2-WT and KCNQ3(1:1:2),the currents at 0 mV of these mutations were decreased by 30%-70%compared to the KCNQ2/3 channel,which could be significantly rescued by applying KCNQ openers including the approved antiepileptic drug retigabine(RTG,10μM),as well as two candidates subjected to clinical trials,pynegabine(HN37,1μM)and XEN1101(1μM).These newly identified pathologic variants enrich the KCNQ2-DEE mutation hotspots in the pore-forming domain.This electrophysiological study provides a rational basis for personalized therapy with KCNQ openers in DEE patients carrying loss-of-function(LOF)mutations in KCNQ2.

关 键 词：developmental and epileptic encephalopathy(DEE) KCNQ2 pore mutations retigabine(RTG) pynegabine(HN37) XEN1101 ELECTROPHYSIOLOGY 

分 类 号：R589.2[医药卫生—内分泌]