Arrhythmogenicity of human SAP97 Mutations in patient specific iPSC-CMs and Mice

患者特异性 iPSC-CM 和小鼠中人类 SAP97 突变的致心律失常性

基本信息

批准号：
8903572
负责人：
JUSTUS M ANUMONWO
金额：
$ 48.49万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2015-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8903572
关键词：
Ablation Accounting Action Potentials Address Alleles Animals Arrhythmia Biogenesis Calcium Calcium Channel Cardiac Cardiac Myocytes Cell membrane Cells Clinical Research Cohort Studies Collaborations DLG1 gene Dependence Detection Disease Echocardiography Electrocardiogram Family history of Frequencies Gene Expression Gene Mutation Gene Proteins Generations Genes Health Heart Heterozygote Homologous Gene Homozygote Human In Vitro Incidence Inherited Investigation Ion Channel Ion Channel Protein Ions Knock-out Knockout Mice Kv4.3 channel Lead Life Link Long QT Syndrome Macromolecular Complexes Measurement Measures Microscopy Missense Mutation Modeling Molecular Mus Muscle Cells Mutation Myocardial Myocardium Patients Pharmaceutical Preparations Phenotype Potassium Potassium Channel Predisposition Property Proteins Recovery Reporting Role Scaffolding Protein Signal Transduction Sodium Sodium Channel Stem cells Stress Susceptibility Gene Syndrome Techniques Testing Therapeutic Intervention Time Up-Regulation Variant Ventricular Ventricular Fibrillation Ventricular Premature Complexes Ventricular Tachycardia Western Blotting adenoviral-mediated heart cell in vivo induced pluripotent stem cell insight interdisciplinary approach male membrane-associated guanylate kinase monolayer mouse model novel protein expression research study sudden cardiac death synapse-associated protein 97 voltage clamp

项目摘要

DESCRIPTION (provided by applicant): Mutations on cardiac ion channel genes can lead to electrical rhythm disturbances known as arrhythmias. Such inherited rhythm disturbances are termed ion channelopathies and include disorders such as Brugada Syndrome (BrS) and Long QT Syndrome (LQTS). In certain instances approximately 70% of channelopathy genes are elude detection. 'MAGUK' proteins scaffold ion channels underneath cell membranes, allowing for efficient electrical signaling. Abnormal expression of a MAGUK could alter ion channel function and thereby compromise electrical excitation. The prototypical MAGUK is the synapse-associated protein 97 (SAP97). SAP97 gene is abundantly expressed in the heart, and there is evidence that SAP97 interacts with ion channels and may therefore regulate excitation. We generated a unique mouse model with the gene knock out (Sap97-KO), to investigate the role of Sap97 in excitation. Sap97-KO mice have abnormalities in ECG and cell electrophysiological properties. Furthermore, a recent clinical study identified mutations in SAP97, which were associated with BrS, and probably the result of abnormally increased expression of a key potassium channel. It is our hypothesis that SAP97 is important for the assembly of cardiac ion channel proteins, and that abnormal SAP97 expression will increase arrhythmia susceptibility. We will test our hypothesis using our mouse model, as well as patient-specific stem cell-derived cardiac myocytes (iPSC-CMs). Three aims will be addressed. 1) To study arrhythmogenic mechanisms in the myocardium of Sap97-KO mice. 2) To investigate Sap97- dependent changes in the expression of potassium, sodium and calcium channels in Sap97-KO mouse cells, and in stem cell-derived cardiac myocytes (iPSC-CMs) of patients with SAP97 mutations in BrS. 3) To study arrhythmia mechanisms associated with human SAP97 mutations in single cells, as well as in layers of iPSC- CMs. Our proposed study will provide insight into molecular mechanisms of channelopathies associated with abnormal SAP97 expression, as well as provide targets for therapeutic intervention.

描述（由申请人提供）：心脏离子通道基因上的突变会导致电节律障碍称为心律不齐。这种继承的节奏扰动称为离子通道病，包括诸如布鲁加达综合征（BRS）和长QT综合征（LQTS）之类的疾病。在某些情况下，大约70％的通道病基因是避免检测。 “ Maguk”蛋白质支架离子通道在细胞膜下方，允许有效的电信号传导。 MAGUK的异常表达可能会改变离子通道功能，从而损害电激发。原型Maguk是突触相关的蛋白97（SAP97）。 SAP97基因在心脏中大量表达，并且有证据表明SAP97与离子通道相互作用，因此可能调节激发。我们生成了一个独特的小鼠模型，它具有基因敲出（SAP97-KO），以研究SAP97在激发中的作用。 SAP97-KO小鼠在ECG和细胞电生理特性中具有异常。此外，最近的一项临床研究确定了与BRS相关的SAP97中的突变，这可能是关键钾通道表达异常增加的结果。我们的假设是SAP97对于心脏离子通道蛋白的组装很重要，并且异常SAP97表达会增加心律不齐的敏感性。我们将使用小鼠模型以及患者特异性干细胞衍生的心肌细胞（IPSC-CMS）检验假设。将解决三个目标。 1）研究SAP97-KO小鼠心肌的心律失常机制。 2）研究SAP97-KO小鼠细胞中钾，钠和钙通道表达的依赖性变化，以及在BR中有SAP97突变的患者的干细胞衍生心肌细胞（IPSC-CMS）中。 3）研究与人类SAP97突变以及IPSC-CMS层中的人体SAP97突变相关的心律失常机制。我们提出的研究将洞悉与SAP97异常表达相关的通道病的分子机制，并提供治疗干预的靶标。