1. The contribution of Na V 1.6 to the efficacy of voltage-gated sodium channel inhibitors in wild type and Na V 1.6 gain-of-function (GOF) mouse seizure control.
- Author
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Johnson JP Jr, Focken T, Karimi Tari P, Dube C, Goodchild SJ, Andrez JC, Bankar G, Burford K, Chang E, Chowdhury S, Christabel J, Dean R, de Boer G, Dehnhardt C, Gong W, Grimwood M, Hussainkhel A, Jia Q, Khakh K, Lee S, Li J, Lin S, Lindgren A, Lofstrand V, Mezeyova J, Nelkenbrecher K, Shuart NG, Sojo L, Sun S, Waldbrook M, Wesolowski S, Wilson M, Xie Z, Zenova A, Zhang W, Scott FL, Cutts AJ, Sherrington RP, Winquist R, Cohen CJ, and Empfield JR
- Subjects
- Animals, Mice, Male, Gain of Function Mutation, Anticonvulsants pharmacology, Mice, Inbred C57BL, NAV1.6 Voltage-Gated Sodium Channel genetics, NAV1.6 Voltage-Gated Sodium Channel metabolism, Seizures drug therapy, Voltage-Gated Sodium Channel Blockers pharmacology
- Abstract
Background and Purpose: Inhibitors of voltage-gated sodium channels (Na
V s) are important anti-epileptic drugs, but the contribution of specific channel isoforms is unknown since available inhibitors are non-selective. We aimed to create novel, isoform selective inhibitors of Nav channels as a means of informing the development of improved antiseizure drugs., Experimental Approach: We created a series of compounds with diverse selectivity profiles enabling block of NaV 1.6 alone or together with NaV 1.2. These novel NaV inhibitors were evaluated for their ability to inhibit electrically evoked seizures in mice with a heterozygous gain-of-function mutation (N1768D/+) in Scn8a (encoding NaV 1.6) and in wild-type mice., Key Results: Pharmacologic inhibition of NaV 1.6 in Scn8aN1768D/+ mice prevented seizures evoked by a 6-Hz shock. Inhibitors were also effective in a direct current maximal electroshock seizure assay in wild-type mice. NaV 1.6 inhibition correlated with efficacy in both models, even without inhibition of other CNS NaV isoforms., Conclusions and Implications: Our data suggest NaV 1.6 inhibition is a driver of efficacy for NaV inhibitor anti-seizure medicines. Sparing the NaV 1.1 channels of inhibitory interneurons did not compromise efficacy. Selective NaV 1.6 inhibitors may provide targeted therapies for human Scn8a developmental and epileptic encephalopathies and improved treatments for idiopathic epilepsies., (© 2024 The Author(s). British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)- Published
- 2024
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