title: The anticonvulsant retigabine suppresses neuronal KV2-mediated currents.
abstract: Enhancement of neuronal M-currents, generated through KV7.2-KV7.5 channels, has gained much interest for its potential in developing treatments for hyperexcitability-related disorders such as epilepsy. Retigabine, a KV7 channel opener, has proven to be an effective anticonvulsant and has recently also gained attention due to its neuroprotective properties. In the present study, we found that the auxiliary KCNE2 subunit reduced the KV7.2-KV7.3 retigabine sensitivity approximately 5-fold. In addition, using both mammalian expression systems and cultured hippocampal neurons we determined that low μM retigabine concentrations had 'off-target' effects on KV2.1 channels which have recently been implicated in apoptosis. Clinical retigabine concentrations (0.3-3 μM) inhibited KV2.1 channel function upon prolonged exposure. The suppression of the KV2.1 conductance was only partially reversible. Our results identified KV2.1 as a new molecular target for retigabine, thus giving a potential explanation for retigabine's neuroprotective properties.
authors.affiliation: Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, 2610 Antwerp, Belgium.|Ion Channel Group, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Jeroen I
authors.initials: JI
authors.lastname: Stas
authors.affiliation: Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, 2610 Antwerp, Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Bocksteins
authors.affiliation: Ion Channel Group, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Camilla S
authors.initials: CS
authors.lastname: Jensen
authors.affiliation: Ion Channel Group, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Nicole
authors.initials: N
authors.lastname: Schmitt
authors.affiliation: Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, 2610 Antwerp, Belgium.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Snyders
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002219:Carbamates / Q000494:pharmacology*; D002460:Cell Line; D057809:HEK293 Cells; D006801:Humans; D051658:KCNQ2 Potassium Channel / Q000378:metabolism; D051659:KCNQ3 Potassium Channel / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010655:Phenylenediamines / Q000494:pharmacology*; D051381:Rats; D051669:Shab Potassium Channels / Q000378:metabolism*
chemical_list: D000927:Anticonvulsants; D002219:Carbamates; D051658:KCNQ2 Potassium Channel; D051659:KCNQ3 Potassium Channel; D010655:Phenylenediamines; D051669:Shab Potassium Channels; C101866:ezogabine