Orlowska Marta K, Krycer James R, Reid Janice D, Mills Richard J, Doran Michael R, Hudson James E
Biomicrofluidics. 2024 Mar 1;18(2):024101. doi: 10.1063/5.0169143. eCollection 2024 Mar.
The heart is a metabolic "omnivore" and adjusts its energy source depending on the circulating metabolites. Human cardiac organoids, a three-dimensional model of the heart wall, are a useful tool to study cardiac physiology and pathology. However, cardiac tissue naturally experiences shear stress and nutrient fluctuations via blood flow , whilst models are conventionally cultivated in a static medium. This necessitates the regular refreshing of culture media, which creates acute cellular disturbances and large metabolic fluxes. To culture human cardiac organoids in a more physiological manner, we have developed a perfused bioreactor for cultures in a 96-well plate format. The designed bioreactor is easy to fabricate using a common culture plate and a 3D printer. Its open system allows for the use of traditional molecular biology techniques, prevents flow blockage issues, and provides easy access for sampling and cell assays. We hypothesized that a perfused culture would create more stable environment improving cardiac function and maturation. We found that lactate is rapidly produced by human cardiac organoids, resulting in large fluctuations in this metabolite under static culture. Despite this, neither medium perfusion in bioreactor culture nor lactate supplementation improved cardiac function or maturation. In fact, RNA sequencing revealed little change across the transcriptome. This demonstrates that cardiac organoids are robust in response to fluctuating environmental conditions under normal physiological conditions. Together, we provide a framework for establishing an easily accessible perfusion system that can be adapted to a range of miniaturized cell culture systems.
心脏是一种代谢“杂食者”，会根据循环代谢物来调整其能量来源。人类心脏类器官是心脏壁的三维模型，是研究心脏生理学和病理学的有用工具。然而，心脏组织会通过血流自然地经历剪切应力和营养物质波动，而传统模型是在静态培养基中培养的。这就需要定期更换培养基，这会造成急性细胞干扰和较大的代谢通量。为了以更符合生理的方式培养人类心脏类器官，我们开发了一种用于96孔板培养的灌注生物反应器。设计的生物反应器使用普通培养板和3D打印机易于制造。其开放系统允许使用传统分子生物学技术，防止流动堵塞问题，并便于进行取样和细胞检测。我们假设灌注培养会创造更稳定的环境，改善心脏功能和成熟度。我们发现人类心脏类器官会快速产生乳酸，导致静态培养下这种代谢物出现大幅波动。尽管如此，生物反应器培养中的培养基灌注和乳酸补充均未改善心脏功能或成熟度。事实上，RNA测序显示转录组几乎没有变化。这表明在正常生理条件下，心脏类器官对波动的环境条件具有很强的耐受性。我们共同提供了一个建立易于使用的灌注系统的框架，该系统可适用于一系列小型化细胞培养系统。
