Generation of four-chambered hearts through organoid fusions

项目摘要 先天性心脏病(CHD)占美国所有活产婴儿的1-2%，其中90%以上 疾病归因于心脏瓣膜和隔膜的缺陷；其中，很少有可能是在小鼠身上建立的模型 由于物种差异和疾病背后的遗传复杂性。作为一种替代方法，人类 诱导多能干细胞(HiPSC)，它在模拟其他疾病方面取得了巨大成功， 在先天性心脏病的建模方面存在不足，特别是在空间敏感机制方面，如 心腔发育。然而，随着有机化合物的出现，这一领域正在取得重大进展 朝着更好的冠心病模型迈进。目前，使用有机化合物的局限性在于当 然而，与内源性组织相比，冠心病建模的潜力是无与伦比的。在这里，我建议使用 一种基于器官融合原理生成具有解剖特征的心脏的新方法： 腔室、瓣膜和隔膜。为此，我们将首先融合一个心房器和一个心室器，以创建 心脏瓣膜。接下来，我们将进一步扩展这一过程，以推进瓣膜的形成并开始 通过融合两个心房和两个心室器官形成的间隔。此外，我们计划使用几个 我们的HiPSC系要么携带CHD突变，要么直接从诊断为 CHDS产生融合的有机类化合物，使我们能够模拟患者的疾病进展。我们 预计这些技术的成功应用将在建模方面提供显著改进 人类正常的心脏发育和先天性心脏缺陷，最终目的是预防和 治疗先天性心脏病。

Project Summary Congenital heart defects (CHDs) account for 1-2% of all live births in the U.S. More than 90% of these diseases are attributed to defects in heart valves and septum; Of which, few have been modeled in mice likely due to species differences and genetic complexities behind the disease. As an alternative approach, human induced pluripotent stem cells (hiPSC), which has demonstrated great success in mimicking other diseases, falls short in the modeling of CHDs, especially in regard to spatial sensitive mechanisms like those involved in heart chamber development. However, with the emergence of organoids, the field is making significant strides toward better CHD models. Currently, the limitations of using organoids resides in the structures integrity when compared to the endogenous tissue, yet, the potential for CHD modelling is unmatched. Here I propose using a novel method based on the organoid fusion principle to generate hearts with anatomically features: chambers, valves and septum. To do this, we will first fuse one atrial and one ventricular organoid to create the cardiac valves. Next, we will further extend this process to advance the formation of the valves and begin formation of the septum by fusing two atrial and two ventricular organoids. Furthermore, we plan to use several of our hiPSC lines either carrying CHD mutations or being directly reprogrammed from patients diagnosed with CHDs to generate fused organoids that will allow us to model the disease progressions in patients. We anticipate that the successful application of these techniques will offer significant improvements in modeling the normal human heart development and congenital heart defects, with the ultimate goal of preventing and treating congenital heart diseases.