scholarly journals Efficacy of RyR2 inhibitor EL20 in induced pluripotent stem cell‐derived cardiomyocytes from a patient with catecholaminergic polymorphic ventricular tachycardia

2021 ◽  
Author(s):  
Tarah A. Word ◽  
Ann P. Quick ◽  
Christina Y. Miyake ◽  
Mayra K. Shak ◽  
Xiaolu Pan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Ventricular Tachycardia ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Polymorphic Ventricular Tachycardia ◽  
Induced Pluripotent

Abstract 15566: Induced Pluripotent Stem Cell-Derived Cardiomyocytes Recapitulate Clinically Observed Refractoriness to Therapeutic β-Blockade in a Patient-Specific Model of Catecholaminergic Polymorphic Ventricular Tachycardia

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Marcela K Preininger ◽  
Rajneesh Jha ◽  
Qingling Wu ◽  
Monalisa Singh ◽  
Joshua T Maxwell ◽  
...  
Keyword(s):  
Stem Cell ◽  
Ventricular Tachycardia ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Polymorphic Ventricular Tachycardia ◽  
Patient Specific ◽  
Blocker Therapy ◽  
Β Blocker ◽  
Induced Pluripotent

Introduction: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by diastolic store overload-induced Ca2+ waves during β-adrenergic receptor (β-AR) stimulation. Mysteriously, β-blockers are ineffective at abolishing stress-induced ventricular arrhythmias in ~25% of patients. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from these CPVT patients offer an attractive system for investigating the phenomenon, but it remains unknown whether iPSC-CMs can recapitulate clinically observed patient-specific drug responses. Hypothesis: This study assessed the hypothesis that patient-specific refractoriness to β-blocker therapy can be observed in vitro using CPVT iPSC-CMs. Methods: We generated iPSC-CMs from a control individual and a CPVT patient insensitive to the widely prescribed β-blocker nadolol, but responsive to flecainide, and compared the efficacy of the two drugs in vitro in diminishing diastolic Ca2+ waves and restoring Ca2+ spark parameters during β-AR stimulation. Results: In CPVT hiPSC-CMs (n = 34), β-AR agonism elicited intense diastolic Ca2+ waves and potentiated unduly frequent, large, and prolonged Ca2+ sparks compared to control iPSC-CMs (n = 12). Pursuant to the patient’s in vivo responses, nadolol-treated CPVT iPSC-CMs (n = 27) demonstrated inadequate improvement of Ca2+ handling defects during β-AR stimulation relative to flecainide-treated CPVT iPSC-CMs (n = 25). Nadolol showed no significant effect on the frequency of diastolic Ca2+ waves, but reduced mean amplitude by 50% (p < 0.0001). In contrast, flecainide reduced both frequency and amplitude by 83% (p < 0.001) and 72% (p < 0.0001), respectively. During nadolol treatment, Ca2+ spark frequency, width, and duration remained significantly altered, while flecainide restored all Ca2+ spark parameters to baseline levels. Conclusions: Clinically observed recalcitrance to β-blocker therapy in individuals with CPVT can be modeled in vitro using patient-derived iPSC-CMs. Furthermore, the efficacy of other drugs such as flecainide can be comparatively evaluated, supporting the use of patient-specific iPSC-CMs as a clinically-relevant implement of precision medicine.

scholarly journals A Novel Mice Model of Catecholaminergic Polymorphic Ventricular Tachycardia Generated by CRISPR/Cas9

2021 ◽  
Author(s):  
cuilan hou ◽  
Xunwei jiang ◽  
Qingzhu Qiu ◽  
Junmin Zheng ◽  
Shujia Lin ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Induced Pluripotent Stem Cell ◽  
Catecholaminergic Polymorphic Ventricular Tachycardia ◽  
Calcium Handling ◽  
Polymorphic Ventricular Tachycardia ◽  
Mice Model ◽  
Isolated Cardiomyocytes ◽  
Therapeutic Targeting ◽  
Protein Levels ◽  
Induced Pluripotent

Catecholaminergic polymorphic ventricular tachycardia (CPVT) has been considered as one of the most important causes of children's sudden cardiac death. Mutations in the genes for RyR2 and CASQ2, two mainly subtypes of CPVT, have been identified. However, the mutation in the gene of TECRL was rarely reported, which could be another genetic cause of CPVT. We evaluated myocardial contractility, electrophysiology, calcium handling in Tecrl knockout (Tecrl KO) mice and human induced pluripotent stem cell-derived cardiomyocytes. Immediately after epinephrine plus caffeine injection, Tecrl KO mice showed much more multiple premature ventricular beats and ventricular tachycardia. The Tecrl KO mice demonstrate CPVT phenotypes. Mechanistically, intracellular calcium amplitude was reduced, while time to baseline of 50 was increased in acute isolated cardiomyocytes. RyR2 protein levels decreased significantly upon cycloheximide treatment in TECRL deficiency cardiomyocytes. Overexpression of TECRL and KN93 can partially reverse cardiomyocytes calcium dysfunction, and this is p-CaMKII/CaMKII dependent. Therefore, a new CPVT mouse model was constructed. We propose a previously unrecognized mechanism of TECRL and provide support for the therapeutic targeting of TECRL in treating CPVT

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