SILENCELQTS: SGK1 inhibition as a novel therapeutic approach in Long QT syndrome

Congenital long-QT syndrome (LQTS) is a rare inherited disorder (prevalence close to 1:2500) associated with life-threatening arrhythmias and sudden cardiac death (SCD) in relatively young and otherwise healthy individuals. LQTS has a heterogeneous genetic basis, with various LQTS subtypes caused by mutations in distinct genes related to cardiac ion channel function. Current symptom-directed therapies aimed at reducing arrhythmia triggering events, including lifestyle changes, beta blockade, and left cardiac sympathetic denervation, only partly prevent arrhythmic events, and SCD still occurs in a substantial number of LQTS patients. Within SILENCE-LQTS, we will investigate a novel, mechanism-targeted therapy, comprising pharmacological inhibition of the serum and glucocorticoid regulated kinase-1 (SGK1). In contrast to current symptom-directed therapies, this novel approach is designed to correct the pro-arrhythmic alterations in sodium homeostasis caused (in)directly by the underlying genetic defect. Efficacy of a SGK1 inhibitor, developed by our industry partner, will be systematically tested in vivo and on the cardiomyocyte and whole heart level in well-established unique transgenic rabbit and mouse models of different LQTS subtypes. Furthermore, its efficacy will be tested in human iPS-derived cardiomyocytes (hiPSC-CMs) obtained from LQTS patients and in 2D/3D engineered hiPSC-CM tissues. These pre-clinical studies will establish the anti-arrhythmic potential of SGK1 inhibition, paving the way for future clinical application aimed at preventing SCD in LQTS.