Global transcriptomic analyses of pluripotent stem cell-derived type II alveolar epithelial-like cells identified by ABCA3:GFP and SFTPCtdTomato bi-fluorescent reporters
We performed transcriptomic profiling of cells derived from human pluripotent stem cells (PSCs) using distal lung directed differentiation protocol previously described to generate alveolar type II epithelial-like cells (iAEC2s). We used the RUES2-STAG human embryonic stem cell line containing bi-fluorescently targeted ABCA3:GFP knock-in fusion reporter and SFTPCtdTomato knock-in reporter to potentially identify heterogenous iAEC2 populations and determine their gene expression profiles. On day 36 of differentiation, we sorted SFTPCtdTomato/ABCA3:GFP double positive (DP), ABCA3:GFP single positive (SP) and reporter double negative (DN) cells for transcriptomic analysis by bulk RNA sequencing. We found DN cells to be enriched in non-lung endodermal cells. Comparison between the reporter positive iAEC2 populations revealed high transcriptomic similarity with expression of canonical AEC2 transcripts in both the DP and SP cells. Analyses of differentially expressed transcript between the DP and SP cells revealed higher levels of surfactant and lamellar body-related transcripts in the DP cells. Moreover, we find enrichment of proliferative markers associated with cellular proliferation indicating the ABCA3:GFP single positive iAEC2s to potentially be a more proliferative subset of iAEC2s. Overall design: Global transcriptomic analysis of day 36 PSC-derived cells comparing SFTPCtdTomato/ABCA3:GFP reporter double positive (DP), ABCA3:GFP reporter single positive (SP), and reporter double negative (DN)  cells in triplicate differentiations (n=3)