iPSC-Derived Cardiomyocytes in Left Ventricular Non-Compaction Cardiomyopathy

描述(申请人提供)：左心室致密化不全(LVNC)心肌病越来越多地被认为是所有年龄段患者心力衰竭的原因。LVNC有一种独特的表型，与扩张型或肥厚型心肌病不同：左室深部过度小梁。与其他形式的心肌病不同，LVNC通常表现为收缩和舒张期功能障碍，以及室性心律失常、壁性血栓和血栓栓塞症。与其他心肌疾病类似，LVNC与多个细胞骨架、肌节、线粒体和离子通道基因的突变有关。然而，与扩张型和肥厚型心肌病的大量数据相比，LVNC的机制基础仍然很不清楚，甚至基本的生理变化也在很大程度上仍然不确定。基因改变的“过度小梁”小鼠模型都有其他先天性心脏缺陷和较高的胚胎致死率，因此不存在良好的模型系统。因此，来自LVNC患者的诱导多能干细胞来源的心肌细胞(IPSC-CMS)为确定心肌细胞自主表型和阐明可能的机制提供了一个独特的机会，最近针对长QT综合征、豹综合征和Timothy综合征的患者特异性IPSC-CMS已经完成。两个患有LVNC的多个受影响成员的家庭将作为LVNC和来自真皮成纤维细胞的对照IPSCs的来源。我们推测，来自LVNC患者的IPSC-CMS将复制疾病表型的关键方面，包括收缩和舒张期功能的改变，心律失常的增加，以及生物力学特性的改变，并作为阐明LVNC机制的平台。我们还假设线粒体功能的改变是LVNC心功能障碍的机制之一。目标1将确定LVNC结构和功能改变的机制。我们将从LVNC和对照受试者中产生IPSC-CMS，鉴定其形态、电生理和生物力学表型，并筛选细胞重塑、钙处理和收缩功能的表型特异性调节物作为疾病机制的候选者。目的2将确定线粒体功能和线粒体动力学改变在LVNC心肌病中的作用。 这项研究将为我提供一个极好的培训平台，让我获得干细胞生物学概念框架和技术方面的培训，并推动我的两个长期职业目标：第一，利用针对特定患者的IPSC-CMS作为工具，增加我们对儿科心血管疾病的分子和细胞基础的了解；第二，使我能够在心力衰竭的干细胞疗法领域令人兴奋的早期阶段发挥作用。有了这项培训计划的支持，作为这一领域为数不多的儿科心脏病专家之一，我将处于一个独特的地位，能够针对导致婴儿和儿童心力衰竭的特定情况调整这些治疗方法。(摘要结束)

DESCRIPTION (provided by applicant): Left ventricular non-compaction (LVNC) cardiomyopathy is increasingly being recognized as a cause of heart failure in patients of all ages. LVNC has a unique phenotype that distinguishes it from dilated or hypertrophic cardiomyopathies: deep hypertrabeculation of the left ventricle. Unlike other forms of cardiomyopathy, LVNC commonly presents with a combination of both systolic and diastolic dysfunction, as well as with ventricular arrhythmias, mural thrombi and thromboembolism. Similar to other cardiomyopathies, LVNC has been associated with mutations in multiple cytoskeletal, sarcomeric, mitochondrial and ion channel genes. However, in contrast to the extensive data available for dilated and hypertrophic cardiomyopathies, the mechanistic basis for LVNC is still largely unknown and even the basic physiologic alterations are still largely undefined. Genetically altered murine models of "hypertrabeculation" all have other congenital heart defects and high embryonic lethality so that good model systems do not exist. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) derived from patients with LVNC thus represent a unique opportunity to define the cardiomyocyte-autonomous phenotype and elucidate potential mechanisms, as has been recently accomplished with patient-specific iPSC-CMs for Long QT syndrome, LEOPARD syndrome and Timothy syndrome. Two families with multiple affected members with LVNC will serve as the source for both LVNC and control iPSCs derived from dermal fibroblasts. We hypothesize that iPSC-CMs derived from LVNC patients will reproduce key aspects of the disease phenotype, including alterations in systolic and diastolic function, increased arrhythmogenicity, and altered biomechanical properties and serve as a platform for elucidation of LVNC mechanisms. We also hypothesize that alterations in mitochondrial function represent one of the mechanisms for LVNC cardiac dysfunction. Aim 1 will determine the mechanisms of structural and functional alterations in LVNC. We will generate iPSC-CMs derived from LVNC and control subjects, characterize their morphologic, electrophysiologic and biomechanical phenotype, and screen phenotype-specific modulators of cell remodeling, calcium handling, and contractile function as candidates for disease mechanism. Aim 2 will determine the role of altered mitochondrial function and mitochondrial dynamics in LVNC cardiomyopathy. This study will serve as an excellent training platform for me to obtain training in both the conceptual framework and techniques of stem cell biology, and further my two long-term career goals: first to utilize patient-specific iPSC-CMs as a tool to increase our understanding of the molecular and cellular basis of pediatric cardiovascular disease; second, so that I can play a role in the exciting early stages of the field of stem cell therapeutics for heart failure. With th support of this training program I will be in a unique position, as one of the few pediatric cardiologists in this area, to adapt these therapies for the specific circumstances leading to heart failure in infants and children. (End of Abstract)