A gain of function ryanodine receptor 2 mutation (R1760W‐RyR2) in catecholaminergic polymorphic ventricular tachycardia. (2nd October 2022)

• Record Type: Journal Article
• Authors: Li, Siyuan; Lv, Tingting; Yang, Jing; Li, Kun; Yang, Ying; Zhang, Ping
• Is Part Of: Clinical and experimental pharmacology and physiology. Volume 50:Number 1(2023)
• Page Start: 39
• Page End: 49
• Publication Date: 2022-10-02
• Subjects: calcium leak -- catecholaminergic polymorphic ventricular tachycardia -- ryanodine receptor -- sudden cardiac death; Clinical pharmacology -- Periodicals; Pharmacology, Experimental -- Periodicals; Physiology, Experimental -- Periodicals; Physiology, Pathological -- Periodicals; 615.1
• DOI: 10.1111/1440-1681.13722
• Languages: English
• ISSNs: 0305-1870

Abstract

Abstract: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome associated with Ca 2+ leak predominantly caused by ryanodine receptor 2 (RyR2) mutations. We identified a R1760W‐RyR2 mutation located between the N‐terminal domain and the central domain of RyR2 in a CPVT patient by DNA sequencing. Recombinant mutant RyR2−2801mcherry plasmid generated by the overlap extension polymerase chain reaction and seamless cloning was transfected in HEK293 cells for the cell model. Single‐cell luminal and cytosolic Ca 2+ imaging was measured by endoplasmic reticulum (ER) luminal Ca 2+ ‐sensitive protein D1ER and Fura‐2 AM on a confocal laser scanning microscope, respectively. We found that in RyR2 mutant cells, the propensity for store‐overload‐induced Ca 2+ release (SOICR) was enhanced representing increased Ca 2+ oscillations, reduced activation and termination thresholds of spontaneous Ca 2+ release; and the sensitivity to cytosolic Ca 2+ activation was increased manifesting reduced steady state ER Ca 2+ levels. Our results indicated that R1760W‐RyR2 mutation induced calcium leak, representing a gain of function. Further, antiarrhythmic drugs propafenone and flecainide significantly suppressed SOICR caused by the R1760W‐RyR2 mutation at a concentration of 20 μM, which was lower than the concentration at which carvedilol suppressed SOICR.