School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St. Lucia 4072, QLD, Australia.
Department for Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.
Proc Natl Acad Sci U S A. 2017 Oct 3;114(40):E8372-E8381. doi: 10.1073/pnas.1707316114. Epub 2017 Sep 15.
The mammalian heart undergoes maturation during postnatal life to meet the increased functional requirements of an adult. However, the key drivers of this process remain poorly defined. We are currently unable to recapitulate postnatal maturation in human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), limiting their potential as a model system to discover regenerative therapeutics. Here, we provide a summary of our studies, where we developed a 96-well device for functional screening in human pluripotent stem cell-derived cardiac organoids (hCOs). Through interrogation of >10,000 organoids, we systematically optimize parameters, including extracellular matrix (ECM), metabolic substrate, and growth factor conditions, that enhance cardiac tissue viability, function, and maturation. Under optimized maturation conditions, functional and molecular characterization revealed that a switch to fatty acid metabolism was a central driver of cardiac maturation. Under these conditions, hPSC-CMs were refractory to mitogenic stimuli, and we found that key proliferation pathways including β-catenin and Yes-associated protein 1 (YAP1) were repressed. This proliferative barrier imposed by fatty acid metabolism in hCOs could be rescued by simultaneous activation of both β-catenin and YAP1 using genetic approaches or a small molecule activating both pathways. These studies highlight that human organoids coupled with higher-throughput screening platforms have the potential to rapidly expand our knowledge of human biology and potentially unlock therapeutic strategies.
哺乳动物的心脏在出生后会经历成熟过程，以满足成年后的功能需求。然而，这一过程的关键驱动因素仍未得到明确界定。我们目前无法在人类多能干细胞衍生的心肌细胞（hPSC-CMs）中再现出生后成熟过程，这限制了它们作为发现再生治疗方法的模型系统的潜力。在这里，我们提供了我们研究的总结，我们在那里开发了一种用于人类多能干细胞衍生的心脏类器官（hCO）的功能筛选的 96 孔设备。通过对超过 10000 个类器官的检测，我们系统地优化了参数，包括细胞外基质（ECM）、代谢底物和生长因子条件，这些参数可以提高心脏组织的活力、功能和成熟度。在优化的成熟条件下，功能和分子特征表明，脂肪酸代谢的转变是心脏成熟的一个关键驱动因素。在这些条件下，hPSC-CMs 对有丝分裂刺激有抗性，我们发现包括β-catenin 和 Yes 相关蛋白 1（YAP1）在内的关键增殖途径受到抑制。脂肪酸代谢在 hCO 中施加的这种增殖障碍可以通过使用遗传方法或同时激活两条途径的小分子来同时激活β-catenin 和 YAP1 来挽救。这些研究表明，人类类器官与高通量筛选平台相结合，有可能迅速扩展我们对人类生物学的认识，并可能解锁治疗策略。
