Modulating the voltage sensor of a cardiac potassium channel shows antiarrhythmic effects

Proc Natl Acad Sci U S A. 2021 May 18;118(20):e2024215118. doi: 10.1073/pnas.2024215118.

Abstract

Cardiac arrhythmias are the most common cause of sudden cardiac death worldwide. Lengthening the ventricular action potential duration (APD), either congenitally or via pathologic or pharmacologic means, predisposes to a life-threatening ventricular arrhythmia, Torsade de Pointes. IKs (KCNQ1+KCNE1), a slowly activating K+ current, plays a role in action potential repolarization. In this study, we screened a chemical library in silico by docking compounds to the voltage-sensing domain (VSD) of the IKs channel. Here, we show that C28 specifically shifted IKs VSD activation in ventricle to more negative voltages and reversed the drug-induced lengthening of APD. At the same dosage, C28 did not cause significant changes of the normal APD in either ventricle or atrium. This study provides evidence in support of a computational prediction of IKs VSD activation as a potential therapeutic approach for all forms of APD prolongation. This outcome could expand the therapeutic efficacy of a myriad of currently approved drugs that may trigger arrhythmias.

Keywords: C28; IKs; KCNQ1; antiarrhythmia; voltage sensor domain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Action Potentials / drug effects*
  • Action Potentials / physiology
  • Amino Acid Substitution
  • Animals
  • Arrhythmias, Cardiac / drug therapy
  • Arrhythmias, Cardiac / genetics
  • Arrhythmias, Cardiac / metabolism
  • Arrhythmias, Cardiac / pathology
  • Calcium / metabolism
  • Dogs
  • Furans / pharmacology
  • Gene Expression
  • Guinea Pigs
  • Heart Atria / cytology
  • Heart Atria / metabolism
  • Heart Ventricles / cytology
  • Heart Ventricles / metabolism
  • Humans
  • KCNQ1 Potassium Channel / chemistry
  • KCNQ1 Potassium Channel / genetics*
  • KCNQ1 Potassium Channel / metabolism
  • Moxifloxacin / pharmacology
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / drug effects
  • Myocytes, Cardiac / metabolism*
  • Oocytes / cytology
  • Oocytes / drug effects
  • Oocytes / metabolism
  • Patch-Clamp Techniques
  • Phenethylamines / pharmacology
  • Potassium / metabolism
  • Primary Cell Culture
  • Pyridines / pharmacology
  • Pyrimidines / pharmacology
  • Small Molecule Libraries / pharmacology*
  • Sodium / metabolism
  • Sulfonamides / pharmacology
  • Transgenes
  • Xenopus laevis

Substances

  • Furans
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human
  • PI103
  • Phenethylamines
  • Pyridines
  • Pyrimidines
  • Small Molecule Libraries
  • Sulfonamides
  • Sodium
  • dofetilide
  • Potassium
  • Calcium
  • Moxifloxacin