Title: Detrimental proarrhythmogenic interaction of Ca2+/calmodulin-dependent protein kinase II and NaV1.8 in heart failure.

Authors: Philipp Bengel, Nataliya Dybkova, Petros Tirilomis, Shakil Ahmad, Nico Hartmann, Belal A Mohamed, Miriam Celine Krekeler, Wiebke Maurer, Steffen Pabel, Maximilian Trum, Julian Mustroph, Jan Gummert, Hendrik Milting, Stefan Wagner, Senka Ljubojevic-Holzer, Karl Toischer, Lars S Maier, Gerd Hasenfuss, Katrin Streckfuß-Bömeke, Samuel Sossalla

Journal, date & volume: Nat Commun, 2021Nov15, 12, 6586

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/34782600

Abstract
An interplay between Ca2+/calmodulin-dependent protein kinase IIδc (CaMKIIδc) and late Na+ current (INaL) is known to induce arrhythmias in the failing heart. Here, we elucidate the role of the sodium channel isoform NaV1.8 for CaMKIIδc-dependent proarrhythmia. In a CRISPR-Cas9-generated human iPSC-cardiomyocyte homozygous knock-out of NaV1.8, we demonstrate that NaV1.8 contributes to INaL formation. In addition, we reveal a direct interaction between NaV1.8 and CaMKIIδc in cardiomyocytes isolated from patients with heart failure (HF). Using specific blockers of NaV1.8 and CaMKIIδc, we show that NaV1.8-driven INaL is CaMKIIδc-dependent and that NaV1.8-inhibtion reduces diastolic SR-Ca2+ leak in human failing cardiomyocytes. Moreover, increased mortality of CaMKIIδc-overexpressing HF mice is reduced when a NaV1.8 knock-out is introduced. Cellular and in vivo experiments reveal reduced ventricular arrhythmias without changes in HF progression. Our work therefore identifies a proarrhythmic CaMKIIδc downstream target which may constitute a prognostic and antiarrhythmic strategy.