Functional screen for genetic causes of hypoplastic left heart syndrome

项目摘要 先天性心脏病（CHD）是最常见的出生缺陷类型，影响约1%的人口， 全球范围内。在CHD中，左心发育不全综合征（HLHS），其中泵血的左心室 氧合血对身体的大部分是畸形的，是最危险的形式和最常见的原因 死亡率的百分比。为了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。虽然HLHS显然是一种遗传性疾病， 对这种疾病的遗传机制和病理生理学知之甚少。的一个主要原因 这种知识差距是缺乏复制这种人类疾病的动物模型。前期工作， 实验室认为青蛙可能是研究HLHS的有价值的动物模型。转录因子的丢失 Ets 1在青蛙中导致HLHS样表型，具有增厚的心室壁和减少的心室容积。 然而，小鼠中Ets 1的遗传缺失导致室间隔缺损和右心室双出口， 但HLHS则不然，这表明该疾病的病理发展中还涉及其他因素。 因此，本项目的目标是使用青蛙模型来确定HLHS的遗传原因。以确定 参与HLHS的其他基因，并更好地了解心脏中不同的结构变化如何相互关联 对于心脏功能，需要有效的功能筛选。目前，没有成像工具可以继续- 以高时空分辨率清晰观察活体蛙胚心脏的完整跳动， 无法直接分析心脏功能。为了应对这一挑战，第一个目标将是建立一个快速- 快速、体积光场显微镜工具，其表现出高特异性和灵敏度， 能够在发育中的胚胎中进行心脏功能的体内检查。有了这个平台，第二个目标将是 当候选HLHS相关基因被克隆时， 变异了结合先进的成像技术和定量分析，这项研究将导致有效的 心脏发育关键基因的发现以及基因间的结构-功能关系 成分和病理生理表型，为揭示HLHS的病因奠定基础。这 新的概念和方法基础也将是有价值的，在更广泛的基础和翻译心脏 research.

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.