Allele-specific RNA Interference Targeting Synonymous Polymorphisms in KCNQ1 as a Novel Therapeutic for Long QT Syndrome

针对 KCNQ1 中同义多态性的等位基因特异性 RNA 干扰作为长 QT 综合征的新疗法

• 批准号: 9119526
• 负责人: Jamie Duane Kapplinger
• 金额: $ 4.86万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9119526
• 关键词: Accounting; Adverse effects; Age; Alleles; Attenuated; Autopsy; Biological Models; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cessation of life; Characteristics; Child; Clinical; Clinical Management; Defect; Development; Disease model; Dominant-Negative Mutation; Event; Family; Frequencies; Generations; Genes; Genetic Polymorphism; Goals; Health; Heart Arrest; Heart Diseases; Hereditary Disease; Individual; Infant; Ion Channel; Lead; Long QT Syndrome; Mediating; Methods; Mutate; Mutation; Nature; Patients; Peptides; Phenotype; Poison; Population; Prevalence; Proteins; RNA Interference; Research; Risk; Role; Romano-Ward Syndrome; Secondary to; Seizures; Severity of illness; Single Nucleotide Polymorphism; Sudden Death; Syncope; Testing; Therapeutic; Therapeutic Studies; Variant; Ventricular Fibrillation; Voltage-Gated Potassium Channel; attenuation; base; clinical application; design; disease phenotype; gene therapy; high risk; induced pluripotent stem cell; knock-down; mutant; novel; novel therapeutic intervention; novel therapeutics; stem; young adult

 DESCRIPTION (provided by applicant): Long QT syndrome (LQTS) is characterized by a prolonged QT interval and an increased risk for syncope, seizures, and sudden cardiac arrest. Ventricular fibrillation (VF) stemming from congenital LQTS is a leading identifiable cause for autopsy-negative sudden unexplained death. With a prevalence of 1 in 2500 individuals, LQTS is the most common cardiac channelopathy and has become a model disease for all other cardiac channelopathies. Over the past decade, there have been substantial improvements made in the clinical management of LQTS. However, the level of breakthrough events, the suboptimal side effect profile, and the fact that none of the current therapeutic strategies directy target the pathogenic substrate of LQTS, specifically the dysregulation of cardiac ion channels, motivates the quest for novel therapeutic strategies for LQTS. The development of patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) has provided a novel model system to study the pathological substrate of LQTS, as well as test novel therapeutics. With mutations in the KCNQ1-encoded Kv7.1 voltage-gated potassium channel accounting for the pathogenic substrate for the largest portion of gene positive LQTS cases, targeting these defects may hold the greatest therapeutic potential. Due to the "dominant-negative" characteristics of KCNQ1 mutations along with the evidence that increased levels of mutant protein lead to increased disease severity, reducing the relative amount of mutated protein should attenuate or correct the disease phenotype. Recent advances in gene therapy have underlined the developing role of RNA interference (RNAi) as a potential therapeutic option in cardiac genetic disorders. These studies have all largely used RNAi targeted against a specific pathogenic mutation. For LQTS, this severely limits the clinical utility of a RNAi-based strategy as the vast majority of pathogenic mutations are family specific. However, targeting high frequency synonymous single nucleotide polymorphisms (sSNPs) in KCNQ1, located on the mutated allele, would allow for allele-specific RNAi in a much larger population creating a much broader clinical application. To this end, we plan to develop allele- specific RNAi targeting the two most common KCNQ1 sSNPs and characterize the effect of this RNAi on the LQTS phenotype of patient-specific iPSC-CMs. By validating a SNP-based RNAi approach in LQTS, this method may also hold potential for other genetically mediated channelopathies and cardiomyopathies.

 描述（由申请人提供）：长 QT 综合征 (LQTS) 的特点是 QT 间期延长以及晕厥、癫痫发作和心脏骤停的风险增加。先天性 LQTS 引起的心室颤动 (VF) 是导致尸检阴性的不明原因猝死的主要原因。 LQTS 的患病率为每 2500 人中就有 1 人，是最常见的心脏通道病，并已成为所有其他心脏通道病的模型疾病。在过去的十年中，LQTS 的临床管理取得了显着的进步。然而，突破性事件的水平、次优的副作用特征以及目前的治疗策略都没有直接针对 LQTS 的致病底物（特别是心脏离子通道的失调）这一事实，促使人们寻求新的 LQTS 治疗策略。 患者特异性诱导多能干细胞衍生心肌细胞 (iPSC-CM) 的开发为研究 LQTS 的病理基础以及测试新疗法提供了一种新的模型系统。由于 KCNQ1 编码的 Kv7.1 电压门控钾通道的突变是大部分基因阳性 LQTS 病例的致病底物，针对这些缺陷可能具有最大的治疗潜力。由于 KCNQ1 突变的“显性失活”特征以及突变蛋白水平增加导致疾病严重程度增加的证据，减少突变蛋白的相对量应该可以减弱或纠正疾病表型。基因治疗的最新进展强调了 RNA 干扰 (RNAi) 作为心脏遗传性疾病潜在治疗选择的作用。这些研究都主要使用针对特定致病突变的 RNAi。对于 LQTS，这严重限制了基于 RNAi 的策略的临床实用性，因为绝大多数致病突变是家族特异性的。然而，针对位于突变等位基因上的 KCNQ1 中的高频同义单核苷酸多态性 (sSNP)，将允许在更大的人群中进行等位基因特异性 RNAi，从而创造更广泛的临床应用。为此，我们计划开发针对两个最常见的 KCNQ1 sSNP 的等位基因特异性 RNAi，并表征该 RNAi 对患者特异性 iPSC-CM LQTS 表型的影响。通过在 LQTS 中验证基于 SNP 的 RNAi 方法，该方法也可能对其他遗传介导的通道病和心肌病具有潜力。