Functional abnormalities in iPSC-derived cardiomyocytes generated from CPVT1 and CPVT2 patients carrying ryanodine or calsequestrin mutations.
Functional abnormalities in iPSC-derived cardiomyocytes generated from CPVT1 and CPVT2 patients carrying ryanodine or calsequestrin mutations.
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DOI：
10.1111/jcmm.12581
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发表时间：
2015-08
影响因子：
5.3
通讯作者：
Binah O
中科院分区：
文献类型：
--
作者：
Novak A;Barad L;Lorber A;Gherghiceanu M;Reiter I;Eisen B;Eldor L;Itskovitz-Eldor J;Eldar M;Arad M;Binah O
儿茶酚胺能多形性室性心动过速（CPVT）是一种遗传性心律失常，其特征是在运动或急性情绪时发生晕厥和猝死。CPVT是由RyR 2或CASQ 2基因突变引起的异常细胞内Ca 2+处理引起的。由于CASQ 2和RyR 2参与兴奋-收缩偶联过程的不同方面，我们假设这些突变与不同的功能和细胞内Ca²+异常相关。为了验证这一假设，我们从分别携带RyR 2 R420 Q和CASQ 2D 307 H突变的CPVT 1和CPVT 2患者中产生了诱导的多能干细胞衍生的心肌细胞（iPSC-CM），并在CPVT 1和CPVT 2 iPSC-CM中研究了（与对照相比）：（i）超微结构特征;（ii）异丙肾上腺素、咖啡因和ryanodine对[Ca 2 +]i瞬时特征的影响。我们的主要发现是：（i）超微结构，CASQ 2和RyR 2突变的心肌细胞比对照心肌细胞发育不良。(ii)而在对照iPSC-CM中，异丙肾上腺素引起正性肌力和负性作用，在突变的心肌细胞中，异丙肾上腺素无效，引起心律失常，或显著增加舒张期[Ca 2 +]i。重要的是，在突变的心肌细胞中未诱导正性肌力作用和负性肌力作用。(iii)咖啡因和ryanodine在突变心肌细胞中的作用与对照心肌细胞不同。我们的研究结果表明，iPSC-CM是有用的研究RyR 2与CASQ 2突变的病理生理后果的相似性/差异CPVT 1和CPVT 2综合征。
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia characterized by syncope and sudden death occurring during exercise or acute emotion. CPVT is caused by abnormal intracellular Ca2+ handling resulting from mutations in the RyR2 or CASQ2 genes. Because CASQ2 and RyR2 are involved in different aspects of the excitation-contraction coupling process, we hypothesized that these mutations are associated with different functional and intracellular Ca²+ abnormalities. To test the hypothesis we generated induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CM) from CPVT1 and CPVT2 patients carrying the RyR2R420Q and CASQ2D307H mutations, respectively, and investigated in CPVT1 and CPVT2 iPSC-CM (compared to control): (i) The ultrastructural features; (ii) the effects of isoproterenol, caffeine and ryanodine on the [Ca2+]i transient characteristics. Our major findings were: (i) Ultrastructurally, CASQ2 and RyR2 mutated cardiomyocytes were less developed than control cardiomyocytes. (ii) While in control iPSC-CM isoproterenol caused positive inotropic and lusitropic effects, in the mutated cardiomyocytes isoproterenol was either ineffective, caused arrhythmias, or markedly increased diastolic [Ca2+]i. Importantly, positive inotropic and lusitropic effects were not induced in mutated cardiomyocytes. (iii) The effects of caffeine and ryanodine in mutated cardiomyocytes differed from control cardiomyocytes. Our results show that iPSC-CM are useful for investigating the similarities/differences in the pathophysiological consequences of RyR2 versus CASQ2 mutations underlying CPVT1 and CPVT2 syndromes.