SK4 K+ channels are therapeutic targets for the treatment of cardiac arrhythmias.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a stress-provoked ventricular arrhythmia, which also manifests sinoatrial node (SAN) dysfunction. We recently showed that SK4 calcium-activated potassium channels are important for automaticity of cardiomyocytes derived from human embryonic stem cells. Here SK4 channels were identified in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from healthy and CPVT2 patients bearing a mutation in calsequestrin 2 (CASQ2-D307H) and in SAN cells from WT and CASQ2-D307H knock-in (KI) mice. TRAM-34, a selective blocker of SK4 channels, prominently reduced delayed afterdepolarizations and arrhythmic Ca2+ transients observed following application of the β-adrenergic agonist isoproterenol in CPVT2-derived hiPSC-CMs and in SAN cells from KI mice. Strikingly, in vivo ECG recording showed that intraperitoneal injection of the SK4 channel blockers, TRAM-34 or clotrimazole, greatly reduced the arrhythmic features of CASQ2-D307H KI and CASQ2 knockout mice at rest and following exercise. This work demonstrates the critical role of SK4 Ca2+-activated K+ channels in adult pacemaker function, making them promising therapeutic targets for the treatment of cardiac ventricular arrhythmias such as CPVT. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Citation

Shiraz Haron-Khun, David Weisbrod, Hanna Bueno, Dor Yadin, Joachim Behar, Asher Peretz, Ofer Binah, Edith Hochhauser, Michael Eldar, Yael Yaniv, Michael Arad, Bernard Attali. SK4 K+ channels are therapeutic targets for the treatment of cardiac arrhythmias. EMBO molecular medicine. 2017 Apr;9(4):415-429

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PMID: 28219898

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