Pabel, Steffen and Mustroph, Julian and Stehle, Thea and Lebek, Simon and Dybkova, Nataliya and Keyser, Andreas and Rupprecht, Leopold and Wagner, Stefan and Neef, Stefan and Maier, Lars S. and Sossalla, Samuel (2020) Dantrolene reduces CaMKII delta C-mediated atrial arrhythmias. EUROPACE, 22 (7). pp. 1111-1118. ISSN 1099-5129, 1532-2092
Full text not available from this repository. (Request a copy)Abstract
Aims In atrial fibrillation (AF), an increased diastolic Ca2+ leak from the sarcoplasmic reticulum (SR) mediated by calcium/calmodulin-dependent-protein-kinaseIIdC (CaMKII) can serve as a substrate for arrhythmia induction and persistence. Dantrolene has been shown to stabilize the cardiac ryanodine-receptor. This study investigated the effects of dantrolene on arrhythmogenesis in human and mouse atria with enhanced CaMKII activity. Methods and results Human atrial cardiomyocytes (CMs) were isolated from patients with AF. To investigate CaMKII-mediated arrhythmogenesis, atrial CMs from mice overexpressing CaMKII delta C (TG) and the respective wildtype (WT) were studied using confocal microscopy (Fluo-4), patch-clamp technique, and in vivo atrial catheter-based burst stimulations. Dantrolene potently reduced Ca2+ spark frequency (CaSpF) and diastolic SR Ca2+ leak in AF CMs. Additional CaMKII inhibition did not further reduce CaSpF or leak compared to dantrolene alone. While the increased SR CaSpF and leak in TG mice were reduced by dantrolene, no effects could be detected in WT. Dantrolene also potently reduced the pathologically enhanced frequency of diastolic SR Ca2+ waves in TG without having effects in WT. As an increased diastolic SR Ca2+ release can induce a depolarizing transient inward current, we could demonstrate that the incidence of afterdepolarizations in TG, but not in WT, mice was significantly diminished in the presence of dantrolene. To translate these findings into an in vivo situation we could show that dantrolene strongly suppressed the inducibility of AF in vivo in TG mice. Conclusion Dantrolene reduces CaMKII-mediated atrial arrhythmogenesis and may therefore constitute an interesting antiarrhythmic drug for treating patients with atrial arrhythmias driven by an enhanced CaMKII activity, such as AF.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | INTERDOMAIN INTERACTIONS; RYANODINE RECEPTORS; CA2+ LEAK; FIBRILLATION; PHOSPHORYLATION; INHIBITION; MYOCARDIUM; Dantrolene; Calcium; Ca2+ leak; Arrhythmias; Atrial fibrillation; Antiarrhythmic agents |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Herz-, Thorax- und herznahe Gefäßchirurgie Medicine > Lehrstuhl für Innere Medizin II |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 19 Mar 2021 07:33 |
| Last Modified: | 19 Mar 2021 07:33 |
| URI: | https://pred.uni-regensburg.de/id/eprint/44255 |
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