• Lacampagne, Alain
• Chen, Shuibing
• Lerman, Bruce B.
• Colombani, Sarah
• Pasquié, Jean-Luc
• Marks, Andrew R.
• Meli, Albano
• Sittenfeld, Leah R.
• Evans, Todd
• Jaffré, Fabrice
• Cheung, Jim W.
• Charrabi, Azzouz
• Reiken, Steven

Abstract

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Polymorphic ventricular tachycardia (PMVT) is a rare genetic disease associated with structurally normal hearts which in 8% of cases can lead to sudden cardiac death, typically exercise-induced. We previously showed a link between the RyR2-H29D mutation and a clinical phenotype of short-coupled PMVT at rest using patient-specific hiPSC-derived cardiomyocytes (hiPSC-CMs). In the present study, we evaluated the effects of clinical and experimental anti-arrhythmic drugs on the intracellular Ca<jats:sup>2+</jats:sup> handling, contractile and molecular properties in PMVT hiPSC-CMs in order to model a personalized medicine approach in vitro.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Previously, a blood sample from a patient carrying the RyR2-H29D mutation was collected and reprogrammed into several clones of RyR2-H29D hiPSCs, and in addition we generated an isogenic control by reverting the RyR2-H29D mutation using CRIPSR/Cas9 technology. Here, we tested 4 drugs with anti-arrhythmic properties: propranolol, verapamil, flecainide, and the Rycal S107. We performed fluorescence confocal microscopy, video-image-based analyses and biochemical analyses to investigate the impact of these drugs on the functional and molecular features of the PMVT RyR2-H29D hiPSC-CMs.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The voltage-dependent Ca<jats:sup>2+</jats:sup> channel inhibitor verapamil did not prevent the aberrant release of sarcoplasmic reticulum (SR) Ca<jats:sup>2+</jats:sup> in the RyR2-H29D hiPSC-CMs, whereas it was prevented by S107, flecainide or propranolol. Cardiac tissue comprised of RyR2-H29D hiPSC-CMs exhibited aberrant contractile properties that were largely prevented by S107, flecainide and propranolol. These 3 drugs also recovered synchronous contraction in RyR2-H29D cardiac tissue, while verapamil did not. At the biochemical level, S107 was the only drug able to restore calstabin2 binding to RyR2 as observed in the isogenic control.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>By testing 4 drugs on patient-specific PMVT hiPSC-CMs, we concluded that S107 and flecainide are the most potent molecules in terms of preventing the abnormal SR Ca<jats:sup>2+</jats:sup> release and contractile properties in RyR2-H29D hiPSC-CMs, whereas the effect of propranolol is partial, and verapamil appears ineffective. In contrast with the 3 other drugs, S107 was able to prevent a major post-translational modification of RyR2-H29D mutant channels, the loss of calstabin2 binding to RyR2. Using patient-specific hiPSC and CRISPR/Cas9 technologies, we showed that S107 is the most efficient in vitro candidate for treating the short-coupled PMVT at rest.</jats:p></jats:sec>

Topics

• impedance spectroscopy
• Calcium
• size-exclusion chromatography
• confocal microscopy