A Precision Medicine Approach to the Rescue of Function on Malignant Calmodulinopathic Long-QT Syndrome.
A Precision Medicine Approach to the Rescue of Function on Malignant Calmodulinopathic Long-QT Syndrome.
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DOI：
10.1161/circresaha.116.309283
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发表时间：
2017-01-06
影响因子：
20.1
通讯作者：
Yue DT
中科院分区：
文献类型：
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作者：
Limpitikul WB;Dick IE;Tester DJ;Boczek NJ;Limphong P;Yang W;Choi MH;Babich J;DiSilvestre D;Kanter RJ;Tomaselli GF;Ackerman MJ;Yue DT
钙调蛋白疾病包括一种新的潜在威胁生命的遗传性心律失常综合征，能够产生严重的长QT综合征(LQTS)，突变涉及CALM1、CALM2或CALM3。这种LQTS的基本基础是L类钙通道(LTCC)钙/钙调素依赖性失活(CDI)的破坏。为了深入了解钙调蛋白疾病的机制基础，并设计出治疗这种形式的LQTS的新的治疗策略。我们从一名D130G-CALM2介导的LQTS患者身上培养并鉴定了IPSC来源的心肌细胞(IPSC-CMS)的功能特性，从而创建了一个设计和测试新治疗策略的平台。患者来源的IPSC-CMS显示(1)动作电位(AP)显著延长，(2)扰乱了钙循环特性，(3)降低了LTCC的CDI。接下来，利用钙调蛋白病患者只在六个冗余的CaM编码等位基因中的一个发生突变的事实，我们设计了一种使用CRISPR干扰(CRISPRi)的策略来选择性地抑制突变基因，而不影响野生型基因。事实上，抑制CALM2的表达在使用D130G-CALM2的IPSC-CMS中产生了功能挽救，如治疗后AP持续时间和CDI的正常化所示。此外，CRISPRi可以设计成选择性地敲除三个CAMP基因中的任何一个，使其成为任何钙调蛋白病的通用治疗策略。总体而言，这一治疗策略为钙调蛋白病患者带来了巨大的希望，因为它代表了一种通用的干预措施，能够专门改变CaM的表达，并可能减少LQTS引发的心脏事件，从而开启了一条通往精准医学的道路。
Calmodulinopathies comprise a new category of potentially life-threatening genetic arrhythmia syndromes capable of producing severe long QT syndrome (LQTS) with mutations involving either CALM1, CALM2, or CALM3. The underlying basis of this form of LQTS is a disruption of Ca2+/CaM-dependent inactivation (CDI) of L-type Ca2+ channels (LTCCs). To gain insight into the mechanistic underpinnings of calmodulinopathies and devise new therapeutic strategies for the treatment of this form of LQTS. We generated and characterized the functional properties of iPSC-derived cardiomyocytes (iPSC-CMs) from a patient with D130G-CALM2-mediated LQTS, thus creating a platform with which to devise and test novel therapeutic strategies. The patient-derived iPSC-CMs display (1) significantly prolonged action potentials (APs), (2) disrupted Ca2+ cycling properties, and (3) diminished CDI of LTCCs. Next, taking advantage of the fact that calmodulinopathy patients harbor a mutation in only one of six redundant CaM-encoding alleles, we devised a strategy using CRISPR interference (CRISPRi) to selectively suppress the mutant gene while sparing the wild-type counterparts. Indeed, suppression of CALM2 expression produced a functional rescue in iPSC-CMs with D130G-CALM2, as shown by the normalization of AP duration and CDI following treatment. Moreover, CRISPRi can be designed to achieve selective knockdown of any of the three CALM genes, making it a generalizable therapeutic strategy for any calmodulinopathy. Overall, this therapeutic strategy holds great promise for calmodulinopathy patients as it represents a generalizable intervention capable of specifically altering CaM expression and potentially attenuating LQTS-triggered cardiac events, thus initiating a path towards precision medicine.