TY - JOUR A1 - Shemer, Yuval A1 - Mekies, Lucy N. A1 - Ben Jehuda, Ronen A1 - Baskin, Polina A1 - Shulman, Rita A1 - Eisen, Binyamin A1 - Regev, Danielle A1 - Arbustini, Eloisa A1 - Gerull, Brenda A1 - Gherghiceanu, Mihaela A1 - Gottlieb, Eyal A1 - Arad, Michael A1 - Binah, Ofer T1 - Investigating LMNA-related dilated cardiomyopathy using human induced Pluripotent Stem Cell-derived cardiomyocytes JF - International Journal of Molecular Sciences N2 - LMNA-related dilated cardiomyopathy is an inherited heart disease caused by mutations in the LMNA gene encoding for lamin A/C. The disease is characterized by left ventricular enlargement and impaired systolic function associated with conduction defects and ventricular arrhythmias. We hypothesized that LMNA-mutated patients' induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) display electrophysiological abnormalities, thus constituting a suitable tool for deciphering the arrhythmogenic mechanisms of the disease, and possibly for developing novel therapeutic modalities. iPSC-CMs were generated from two related patients (father and son) carrying the same E342K mutation in the LMNA gene. Compared to control iPSC-CMs, LMNA-mutated iPSC-CMs exhibited the following electrophysiological abnormalities: (1) decreased spontaneous action potential beat rate and decreased pacemaker current (I\(_f\)) density; (2) prolonged action potential duration and increased L-type Ca\(^{2+}\) current (I\(_{Ca,L}\)) density; (3) delayed afterdepolarizations (DADs), arrhythmias and increased beat rate variability; (4) DADs, arrhythmias and cessation of spontaneous firing in response to β-adrenergic stimulation and rapid pacing. Additionally, compared to healthy control, LMNA-mutated iPSC-CMs displayed nuclear morphological irregularities and gene expression alterations. Notably, KB-R7943, a selective inhibitor of the reverse-mode of the Na\(^+\)/Ca\(^{2+}\) exchanger, blocked the DADs in LMNA-mutated iPSC-CMs. Our findings demonstrate cellular electrophysiological mechanisms underlying the arrhythmias in LMNA-related dilated cardiomyopathy. KW - LMNA KW - dilated cardiomyopathy KW - iPSC-CMs KW - electrophysiology KW - arrhythmia Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285673 SN - 1422-0067 VL - 22 IS - 15 ER -