Restores Epithelial Identity and Mitigates Lung Fibrosis

In this study, we investigated how S100A2 overexpression, hypoxic stress, and 2D monolayer culture conditions disrupt the epithelial identity of human iPSC-derived alveolar type 2 cells (iAT2s), a key pathological feature of lung fibrosis. Using defined perturbations, we examined how each factor contributes to cellular reprogramming, loss of AT2 fate, and induction of stress-responsive or basal-like transcriptional states. Together, these analyses provide mechanistic insight into how microenvironmental and molecular cues drive AT2 cell dysfunction during fibrotic remodeling. Overall design: We analyzed six experimental groups of iAT2 cells subjected to distinct perturbations to model AT2 cell stress and plasticity: 1. iAT2 normoxia control 2. iAT2 under hypoxia 3. iAT2 control 4. iAT2 with S100A2 overexpression 5. iAT2 cultured in 2D monolayer conditions 6. iAT2 transitioned from 2D monolayer back to 3D culture This design allowed us to compare how molecular overexpression, environmental stress, and loss of 3D niche cues individually and collectively influence AT2 epithelial identity.