The importance of oxygen tension in in vitro cultures and its effect on embryonic stem cell (ESC) differentiation has been widely acknowledged. Research has mainly focussed on ESC maintenance or on one line of differentiation and only few studies have examined the potential relation between oxygen tension during ESC maintenance and differentiation. In this study we investigated the influence of atmospheric (20%) versus physiologic (5%) oxygen tension in ESC cultures and their differentiation within the cardiac and neural embryonic stem cell tests (ESTc, ESTn). Oxygen tension was set at 5% or 20% and cells were kept in these conditions from starting up cell culture until use for differentiation. Under these oxygen tensions, ESC culture showed no differences in proliferation and gene and protein expression levels. Differentiation was either performed in the same or in the alternative oxygen tension compared to ESC culture creating four different experimental conditions. Cardiac differentiation in 5% instead of 20% oxygen resulted in reduced development of spontaneously beating cardiomyocytes and lower expression of cardiac markers Nkx2.5, Myh6 and MF20 (myosin), regardless whether ESC had been cultured in 5% or 20% oxygen tension. As compared to the control (20% oxygen during stem cell maintenance and differentiation), neural differentiation in 5% oxygen with ESC cultured in 20% oxygen led to more cardiac and neural crest cell differentiation. The opposite experimental condition of neural differentiation in 20% oxygen with ESC cultured in 5% oxygen resulted in more glial differentiation. ESC that were maintained and differentiated in 5% oxygen showed an increase in neural crest and oligodendrocytes as compared to 20% oxygen during stem cell maintenance and differentiation. This study showed major effects on ESC differentiation in ESTc and ESTn of oxygen tension, which is an important variable to consider when designing and developing a stem cell-based in vitro system.

体外氧分压的重要性培养物及其对胚胎干细胞 (ESC) 分化的影响已得到广泛认可。研究主要集中在 ESC 维持或一种分化上，只有少数研究检查了 ESC 维持和分化过程中氧张力之间的潜在关系。在这项研究中，我们调查了 ESC 培养物中大气 (20%) 与生理 (5%) 氧张力的影响及其在心脏和神经胚胎干细胞测试 (ESTc, ESTn) 中的分化。氧张力设置为 5% 或 20%，从细胞培养开始直到用于分化，细胞都保持在这些条件下。在这些氧张力下，ESC 培养物在增殖和基因和蛋白质表达水平上没有显示出差异。与 ESC 培养相比，分化是在相同或不同的氧张力下进行的，创造了四种不同的实验条件。5% 而不是 20% 氧气的心脏分化导致自发搏动心肌细胞的发育减少和心脏标志物的表达降低Nkx2.5、Myh6和 MF20（肌球蛋白），无论 ESC 是在 5% 还是 20% 氧张力下培养。与对照（干细胞维持和分化期间的 20% 氧气）相比，5% 氧气中的神经分化和 ESC 在 20% 氧气中培养导致更多的心脏和神经嵴细胞分化。在 20% 氧气中与 ESC 在 5% 氧气中培养的神经分化相反的实验条件导致更多的神经胶质分化。在干细胞维持和分化过程中，与 20% 氧气相比，在 5% 氧气中维持和分化的 ESC 显示出神经嵴和少突胶质细胞的增加。该研究表明氧张力对 ESC 分化的 ESTc 和 ESTn 产生重大影响，这是设计和开发基于干细胞的体外干细胞时要考虑的重要变量。 系统。