Screening of factors inducing alveolar type 1 epithelial cells using human pluripotent stem cells

• Published in: Stem cell reports Vol. 19; no. 4; pp. 529 - 544
• Main Authors: Ohnishi, Yuko, Masui, Atsushi, Suezawa, Takahiro, Mikawa, Ryuta, Hirai, Toyohiro, Hagiwara, Masatoshi, Gotoh, Shimpei
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09-04-2024; Elsevier
• Subjects: AKT; alveolar epithelial differentiation; high-throughput screening; iPSC; lung regeneration; organoid; YAP/TAZ; alveolar epithelial differentiation; YAP/TAZ; iPSC; high-throughput screening; AKT; lung regeneration; organoid
• DOI: 10.1016/j.stemcr.2024.02.009
• EISSN: 2213-6711

Alveolar type 2 (AT2) epithelial cells are tissue stem cells capable of differentiating into alveolar type 1 (AT1) cells for injury repair and maintenance of lung homeostasis. However, the factors involved in human AT2-to-AT1 cell differentiation are not fully understood. Here, we established SFTPCGFP and AGERmCherry-HiBiT dual-reporter induced pluripotent stem cells (iPSCs), which detected AT2-to-AT1 cell differentiation with high sensitivity and identified factors inducing AT1 cell differentiation from AT2 and their progenitor cells. We also established an “on-gel” alveolar epithelial spheroid culture suitable for medium-throughput screening. Among the 274 chemical compounds, several single compounds, including LATS-IN-1, converted AT1 cells from AT2 and their progenitor cells. Moreover, YAP/TAZ signaling activation and AKT signaling suppression synergistically recapitulated the induction of transcriptomic, morphological, and functionally mature AT1 cells. Our findings provide novel insights into human lung development and lung regenerative medicine.
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•An mCherry-HiBiT reporter iPSC line was useful for the screening of AT1 cell inducers•On-gel alveolar epithelial spheroid culture facilitated medium-throughput screening•YAP/TAZ activation and AKT inhibition synergistically promoted AT1 differentiation
In the alveolar epithelium, AT2 cells maintain homeostasis and regeneration through self-renewal and differentiation into AT1 cells. A dual-reporter cell line and on-gel alveolar epithelial spheroid culture were established to quantitatively evaluate AT1 differentiation. Our findings showed that YAP/TAZ activation and AKT inhibition synergistically promoted AT1 cells, thereby providing novel insights into AT1 differentiation and contributing to lung regenerative medicine.