Disruption of RBM20 causes atrial electrophysiological disturbances

Abstract

BackgroundDilated cardiomyopathy (DCM) is a leading cause of heart failure, with 30-50 % of cases attributed to familial inheritance. Mutations in RNA-binding motif protein 20 (RBM20) account for 3-5 % of cases and are associated with severe DCM and ventricular arrhythmias. However, the role of RBM20 mutations in atrial cardiomyopathy (AtCM) and atrial fibrillation (AF) remains underexplored. This study investigates the effects of the RBM20-R636Q mutation on atrial electrophysiology and evaluates sodium-glucose co-transporter (SGLT) inhibitors as potential therapeutics. ResultsRbm20-R636Q mice exhibited atrial remodeling, including hypertrophy, left atrial enlargement, and shortened action potential duration at 90% repolarization (APD90). Compared with RBM20-knockout and laminopathy models, RBM20-R636Q mice showed distinct reductions in Ito / IKur without changes in IK,sus or IK,tail currents, alongside TASK-1 potassium current upregulation and alterations of ICaL. SGLT inhibitors (sotagliflozin, empagliflozin, dapagliflozin) reduced AP inducibility and partially restored APD90, with effects comparable to lidocaine, suggesting a role in modulating peak sodium currents. ConclusionsRBM20 mutations contribute to atrial remodeling, promoting AtCM and AF. SGLT inhibitors demonstrate therapeutic potential by modulating atrial electrophysiology and reducing arrhythmogenesis, offering a promising strategy for managing RBM20-related cardiac disorders. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/711772v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@7bcccaorg.highwire.dtl.DTLVardef@1c20b0dorg.highwire.dtl.DTLVardef@63bbcdorg.highwire.dtl.DTLVardef@1bea67f_HPS_FORMAT_FIGEXP M_FIG C_FIG