Generation of human alveolar epithelial type I cells from pluripotent stem cells
Claire L. Burgess, Jessie Huang, Pushpinder Bawa, Konstantinos–Dionysios Alysandratos, Kasey Minakin, Lauren J. Ayers, Michael P. Morley, Apoorva Babu, Carlos Villacorta-Martín, Maria Yampolskaya, Anne Hinds, Bibek R. Thapa, Feiya Wang, Adeline Matschulat, Pankaj Mehta, Edward E. Morrisey, Xaralabos Varelas, Darrell N. Kotton
Abstract
Alveolar epithelial type I cells (AT1s) line the gas exchange barrier of the distal lung and have been historically challenging to isolate or maintain in cell culture. Here, we engineer a human in vitro AT1 model system via directed differentiation of induced pluripotent stem cells (iPSCs). We use primary adult AT1 global transcriptomes to suggest benchmarks and pathways, such as Hippo-LATS-YAP/TAZ signaling, enriched in these cells. Next, we generate iPSC-derived alveolar epithelial type II cells (AT2s) and find that nuclear YAP signaling is sufficient to promote a broad transcriptomic shift from AT2 to AT1 gene programs. The resulting cells express a molecular, morphologic, and functional phenotype reminiscent of human AT1 cells, including the capacity to form a flat epithelial barrier producing characteristic extracellular matrix molecules and secreted ligands. Our results provide an in vitro model of human alveolar epithelial differentiation and a potential source of human AT1s.