Generation of Alveolar Epithelial Spheroids via Isolated Progenitor Cells from Human Pluripotent Stem Cells

No methods for isolating induced alveolar epithelial progenitor cells (AEPCs) from human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) have been reported. Based on a study of the stepwise induction of alveolarepithelial cells (AECs), we identified carboxypeptidase M (CPM) as a surface marker of NKX2-1 + ‘‘ventralized’’ anterior foregut endoderm cells (VAFECs) in vitro and in fetalhumanandmurinelungs.UsingSFTPC-GFPreporterhPSCsanda3Dcoculturesystemwithfetalhumanlungfibroblasts,weshowed that CPM + cells isolated from VAFECs differentiate into AECs, demonstrating that CPM is a marker of AEPCs. Moreover, 3D coculture differentiation of CPM + cells formed spheroids with lamellar-body-like structures and an increased expression of surfactant proteins compared with 2D differentiation. Methods to induce and isolate AEPCs using CPM and consequently generate alveolar epithelial spheroids would aid human pulmonary disease modeling and regenerative medicine.