Mimicking the niche of lung epithelial stem cells and characterization of several effectors of their in vitro behavior

• Published in: Stem cell research Vol. 15; no. 1; pp. 109 - 121
• Main Authors: Hegab, Ahmed E., Arai, Daisuke, Gao, Jingtao, Kuroda, Aoi, Yasuda, Hiroyuki, Ishii, Makoto, Naoki, Katsuhiko, Soejima, Kenzo, Betsuyaku, Tomoko
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.07.2015; Elsevier
• Subjects: Animals; Cell Differentiation - drug effects; Cell Proliferation - drug effects; Cells, Cultured; Coculture Techniques; Endothelial Cells - cytology; Endothelial Cells - drug effects; Epithelial Cells - cytology; Epithelial Cells - drug effects; Epithelial Cells - metabolism; Fibroblast Growth Factors - metabolism; Fibroblasts - cytology; Fibroblasts - drug effects; Fibroblasts - metabolism; Lung - cytology; Mice, Inbred C57BL; Protein Kinase Inhibitors - pharmacology; Receptors, Fibroblast Growth Factor - metabolism; Stem Cell Niche - drug effects; Stem Cells - cytology; Stem Cells - drug effects; Stem Cells - metabolism; MTEC; SCS; CFE; ROCK-I; ABSC; Alk5-I; WLC
• ISSN: 1873-5061; 1876-7753
• DOI: 10.1016/j.scr.2015.05.005

The niche surrounding stem cells regulate their fate during homeostasis and after injury or infection. The 3D organoid assay has been widely used to study stem cells behavior based on its capacity to evaluate self-renewal, differentiation and the effect of various medium supplements, drugs and co-culture with supportive cells. We established an assay to study both lung and trachea stem cells in vitro. We characterized their proliferation and differentiation spectrum at baseline then evaluated the effect of co-culturing with fibroblasts and endothelial cells and/or treating with several biologically relevant substances as possible contributors to their niche. We found that lung epithelial (but not tracheal basal) stem cells require co-culture with stromal cells to undergo clonal proliferation and differentiation. Fibroblasts were more efficient than endothelial cells in offering this support and the pattern of support varied based on the tissue origin of the stromal cells. Treating distal lung epithelial or basal stem cells with FGF2, FGF9, FGF10, LIF as well as ALK5 and ROCK inhibitors increased their colony formation efficiency and resulted in variable effects on colonies number, size and differentiation spectrum. This model and findings pave the way for better understanding of lung stem cell niche components and factors that can manipulate lung stem cell behavior. [Display omitted] •A standardized assay to study lung and trachea stem cells in vitro is established.•Lung stem cells require close proximity to stromal cells.•Support offered by stromal cells varies according to their type and tissue of origin.•Several potential niche effectors variably influenced stem cells' behavior in vitro.