Sacubitrilat exerts potent antiarrhythmic effects through activation of natriuretic peptide receptor-C

Sacubitril, a neprilysin inhibitor used in the treatment of heart failure, has been shown to exert direct antiarrhythmic effects on ventricular cardiomyocytes. However, the underlying mechanisms and molecular targets remain to be elucidated. This study, therefore, aimed at investigating the direct antiarrhythmic properties of sacubitril and exploring a potential involvement of natriuretic peptides in the context of arrhythmia-induced cardiomyopathy (AIC).

Diastolic sarcoplasmic reticulum (SR) Ca2+ leak was induced in isolated murine ventricular cardiomyocytes by enhancing late sodium current with ATX-II, and in human induced pluripotent stem cell-derived ventricular cardiomyocytes (iPSC-CM) by 24-h tachyarrhythmic stimulation. Diastolic Ca2+ leak and Ca2+ transient kinetics were quantified using confocal and epifluorescence microscopy, while pharmacological tools (CNP, ANP, NPR-C agonist cANP4-23, and NPR-C blocker osteocrin) dissected receptor involvement. In silico modelling explored potential binding sites of sacubitrilat to NPR-C. CNP, but not ANP, reversed the increases in Ca2+ spark frequency induced by ATX-II in murine ventricular cardiomyocytes. This effect was reproduced by selective NPR-C activation with cANP4-23 and abolished by NPR-C blockade with osteocrin. In a similar manner, sacubitrilat suppressed pathological SR Ca2+ leak in both murine and human iPSC-derived cardiomyocytes. This protection was fully lost when NPR-C was inhibited. Sacubitrilat did not cause any significant alterations in systolic Ca2+ release and SR Ca2+ load in murine ventricular cardiomyocytes. In silico modelling identified a plausible hydrophobic binding pocket for sacubitrilat at the NPR-C dimer, thus supporting a direct receptor interaction.

These data indicate that activation of NPR-C is both necessary and sufficient for the potent antiarrhythmic actions of sacubitrilat, mediating a selective reduction of arrhythmogenic SR Ca2+ leak in murine ventricular cardiomyocytes as well as in a cellular model of human AIC in iPSC-CM. NPR-C therefore emerges as a promising molecular target for the development of novel antiarrhythmic therapies suitable for patients with heart failure and arrhythmia-induced cardiomyopathy.