Figure 7

Prominin-1⁺ cells expanded from lungs of bleomycin-treated mice fail to acquire phenotype of type II alveolar epithelial cells. Seven days after treatment with bleomycin, lungs with ongoing inflammation of C57Bl/6 mice were dissected and prominin-1-positive cells were isolated using magnetic cell sorting and cultured in the culture expansion medium (CEM) for 2-3 weeks. Expanded cells showed a round, semi-adherent phenotype, were positive for prominin-1, CD45, CXCR4, c-kit, and mostly negative for F4/80, SP-C and fibronectin (A). Further, sorted prominin-1⁺ cells were stimulated for different lineage differentiation. In the presence of TGF-β prominin-1⁺ progenitors formed fibronectin-positive cells and up-regulated myofibroblast-specific mRNA levels: Fn1, Col1a1 and Acta2 (B). Bars represent mean ± SD from at least 5 individual cell cultures. Addition of M-CSF to cultures resulted in formation of E.coli phagocytising F4/80-positive cells (C). Prominin-1⁺ cells derived from inflamed lungs cultured in the SAGM for 14 days failed to produce SP-C at protein and mRNA levels (D). Abbreviations: ctr prom-1- prominin-1⁺ cells isolated from healthy lung, BLM-prom-1- prominin-1⁺ cells isolated from the inflamed lung 7 days after bleomycin instillation. DAPI visualized cell nuclei. Bars = 20 μm. (**) - p < 0.01, (***) - p < 0.001.