Functional screen for genetic causes of hypoplastic left heart syndrome

项目总结 先天性心脏病(CHDS)是最常见的出生缺陷类型，影响约1%的人口。 在全球范围内。在CHD中，左心发育不全综合征(HLHS)，即左心室泵浦 含氧血液给身体的大部分是畸形的，是最危险的形式和最常见的原因 先天疾病婴儿死亡的风险。要实现疾病的早期诊断和干预，长期目标是 了解HLHS的分子和细胞机制。尽管HLHS显然是一种遗传性疾病， 人们对这种疾病的遗传机制和病理生理学知之甚少。一个主要原因是 这种知识差距就是缺乏复制这种人类疾病的动物模型。前期工作来自 实验室表明，青蛙可能是研究HLHS的一个有价值的动物模型。转录因子的缺失 在青蛙中，Ets1导致了HLHS样的表型，室壁增厚，腔体积减小。 然而，在小鼠中，Ets1的基因缺失会导致室间隔缺陷和右室双出口， 但不是HLHS，这表明其他因素参与了疾病的病理发展。 因此，该项目的目标是使用青蛙模型来确定HLHS的遗传原因。要确定 更多参与HLHS的基因，并更好地理解心脏不同结构变化的相互关系 对于心功能来说，需要一种有效的功能筛查。目前，还没有成像工具可以继续- 在体内以高时空分辨率观察整个跳动的胚胎蛙心，使 不可能直接分析心脏功能。为了应对这一挑战，第一个目标将是开发一种快速- 速度快、体积小的光场显微镜工具，表现出高特异性和敏感度，但光损伤较小 能够在体内检查发育中的胚胎的心脏功能。有了这个平台，第二个目标将是 当候选HLHS相关基因为 变异了。结合先进的成像技术和定量分析，这项研究将导致高效的 心脏发育关键基因的发现及基因间结构功能关系的研究 成分和病理生理表型，为揭示HLHS的病因奠定了基础。这 新的概念和方法基础也将在更广泛的基础心脏和翻译心脏中具有价值 研究。

PROJECT SUMMARY Congenital heart diseases (CHDs) are the most common type of birth defect and impact about 1% of the popu- lation worldwide. Among CHDs, hypoplastic left heart syndrome (HLHS), in which the left ventricle that pumps oxygenated blood to most of the body is malformed, is the most dangerous form and the most common cause of death in infants with CHDs. To achieve early diagnosis and intervention of the disease, the long-term goal is to understand the molecular and cellular mechanisms of HLHS. Although HLHS is evidently a genetic disease, little is known about the genetic mechanisms and pathophysiology underlying the disease. One major reason for such a knowledge gap is the lack of animal models replicating this human disease. Preliminary work from the lab suggests that frog may represent a valuable animal model for studying HLHS. The loss of transcription factor Ets1 in frog leads to an HLHS-like phenotype, with thickened ventricular wall and reduced chamber volume. Genetic deletion of Ets1 in mice, however, leads to ventricular septal defects and double outlet right ventricle, but not HLHS, suggesting the involvement of additional factors in the pathological development of the disease. Therefore, the goal of this project is to use the frog model to identify genetic causes for HLHS. To determine additional genes involved in HLHS and better understand how different structural changes in the heart correlate to cardiac function, an efficient functional screen is needed. Currently, there is no imaging tool that can continu- ously observe the entire beating embryonic frog heart in vivo with a high spatiotemporal resolution, making the direct analysis of cardiac function impossible. To address this challenge, the first aim will be developing a fast- speed, volumetric light-field microscopy tool that exhibits high specificity and sensitivity yet low photodamage to enable in vivo examination of heart function in developing embryos. With this platform, the second aim will be examining heart anatomy as well as heart function in frog embryos when candidate HLHS-related genes are mutated. Combining advanced imaging technology and quantitative analysis, this study will lead to the efficient discovery of critical genes involved in heart development and the structure-function relations between genetic components and pathophysiological phenotypes, laying the foundation to uncover the etiology of HLHS. This novel conceptual and methodological groundwork will also be valuable in broader basic and translational cardiac research.