Profiling of cultured primary stromal cells from human lung

Recent publications have implicated senescent alveolar epithelial cells as the cause of lung remodeling and fibrosis. We sought to better understand the heterogeneity in the basal epithelial cell population, especially with regards to characterizing senescent alveolar epithelial cells. The basal cell cultures contain a portion of cells that display a senescent phenotype and stain for a marker of senescence. We also sought to understanding the heterogeneity in the fibroblast population. Primary fibroblast cultures stained with myofibroblast markers show that only a portion of the cells are positive for ACTA2, suggesting that there are at least two distinct populations in this particular cell type. The diversity in this cell type remains uncharacterized at this point. Overall design: Primary lung basal epithelial cells (EPCAM+) and fibroblasts (CD90+) were isolated from a human lung explant and cultured in appropriate media to enhance expansion. Subsequent passaging enriched cultures for either epithelial or fibroblast cell types. Cells at passage 4 were processed for single-cell RNA-seq to investigate replicative senescence in epithelial cells and fibroblast subtypes in culture.