Alveolar epithelial type II cells (AEC2s) are the facultative progenitors of lung alveoli and serve as the surfactant-producing cells of air-breathing organisms. Although primary human AEC2s are difficult to maintain stably in cell cultures, recent advances have facilitated the derivation of AEC2-like cells from human pluripotent stem cells (hPSCs) in vitro. Here, we provide a detailed protocol for the directed differentiation of hPSCs into self-renewing AEC2-like cells that can be maintained for up to 1 year in culture as epithelial-only spheres without the need for supporting mesenchymal feeder cells. The month-long protocol requires recapitulation of the sequence of milestones associated with in vivo development of the distal lung, beginning with differentiation of cells into anterior foregut endoderm, which is followed by their lineage specification into NKX2-1+ lung progenitors and then distal/alveolar differentiation to produce progeny that express transcripts and possess functional properties associated with AEC2s.

中文翻译：

---

从人多能干细胞中衍生出自我更新的肺泡上皮 II 型细胞。

肺泡上皮 II 型细胞 (AEC2) 是肺泡的兼性祖细胞，是呼吸空气生物的表面活性剂产生细胞。尽管原代人类 AEC2 难以在细胞培养物中稳定维持，但最近的进展促进了在体外从人类多能干细胞 (hPSC) 衍生 AEC2 样细胞。在这里，我们提供了一个详细的协议，用于将 hPSC 定向分化为自我更新的 AEC2 样细胞，这些细胞可以在培养中作为仅上皮的球体维持长达 1 年，而无需支持间充质饲养细胞。为期一个月的方案需要重述与远端肺体内发育相关的一系列里程碑，从细胞分化为前肠内胚层开始，