Conventional human pluripotent stem cells (hPSCs), known for being in a primed state, are pivotal for both basic research and clinical applications since such cells produce various types of differentiated cells. Recent reports on PSCs shed light on the pluripotent hierarchy of stem cells and have promoted the exploration of new stem cell states along with their culture systems. Human naïve PSCs are expected to provide further knowledge of early developmental mechanisms and improvements for differentiation programmes in the regenerative therapy of conventionally primed PSCs. However, practical challenges exist in using naïve-state PSCs such as determining the conditions for hypoxic culture condition and showing limited stable cellular proliferation. Here, we have developed new leukemia inhibitory factor dependent PSCs by applying our previous work, the combination of dibenzazepine and a DOT1L inhibitor to achieve the stable culture of naïve-state PSCs. The potential of these cells to differentiate into all three germ layers was shown both in vitro and in vivo. Such new naïve-state PSCs formed dome-shaped colonies at a faster rate than conventional, primed-state human induced PSCs and could be maintained for an extended period in the absence of hypoxic culture conditions. We also identified relatively high expression levels of naïve cell markers. Thus, non-hypoxia treated, leukemia inhibitory factor-dependent PSCs are anticipated to have characteristics similar to those of naïve-like PSCs, and to enhance the utility value of PSCs. Such naïve PSCs may allow the molecular characterization of previously undefined naïve human PSCs, and to ultimately contribute to the use of human pluripotent stem cells in regenerative medicine and disease modelling.

已知处于启动状态的常规人类多能干细胞（hPSC）对于基础研究和临床应用都是至关重要的，因为此类细胞会产生各种类型的分化细胞。最近关于PSC的报道阐明了干细胞的多能性层次，并促进了对新的干细胞状态及其培养系统的探索。预期人类天真PSC可以提供有关常规启动PSC再生治疗中早期发育机制和分化程序改进的进一步知识。但是，在使用朴素状态的PSC方面存在实际挑战，例如确定缺氧培养条件的条件并显示有限的稳定细胞增殖。在这里，我们通过应用我们以前的工作开发了新的依赖白血病抑制因子的PSC，地苯并ze庚因和DOT1L抑制剂的组合可实现幼稚状态PSC的稳定培养。这些细胞均具有分化为所有三个细菌层的潜力体外和体内。这种新的天真状态的PSC形成圆顶状菌落的速率比传统的原始状态的人类诱导的PSC更快，并且可以在没有低氧培养条件的情况下长期保存。我们还确定了相对较高的原始细胞标志物表达水平。因此，预期非低氧治疗的，白血病抑制因子依赖性的PSC具有与幼稚样PSC相似的特征，并提高了PSC的实用价值。这种幼稚的PSC可能允许对先前未定义的幼稚的人类PSC进行分子表征，并最终有助于在再生医学和疾病建模中使用人类多能干细胞。