Fig. 1

Isolation and characterization of a potential stem cell population from mouse lung. a Lung stem cells (LSCs) were sorted by MoFlo Astrios according to the following marker-based sorting strategy: positive for Sca1 and negative for CD45 and CD31. b LSCs were induced to differentiate into osteoblasts, chondroblasts, and adipocytes by incubating with defined factors. (i–iii) Differentiation phenotype was confirmed by (i) alizarin red staining of osteoblasts, (ii) alcian blue staining of chondroblasts, and (iii) fat droplets that stained red with oil red; scale bars, 100 μm. c Flow cytometry analysis showed that LSCs exhibited characteristics of mesenchymal stem cells: positive for CD29, CD44, CD105, and Sca1 and negative for CD45, CD31, Ter119, and Flk1. d Flow cytometry analysis (i) and immunofluorescent staining (ii) results showed that LSCs expressed fibroblast growth factor receptor 2 (FGFR2); scale bars, 200 μm. e Immunofluorescent staining results showed that adding 50 ng/mL fibroblast growth factor 10 (FGF10) caused marked induction of SP-C and an increased number of Ki67⁺ cells, but it did not increase AQP5, CCSP, α-SMA, or CD31 levels; scale bars, 40 μm. f Flow cytometry analysis showed that FGF 10 caused an increased number of Ki67⁺ cells and SP-C⁺ cells but not CCSP⁺ cells. g The statistical analysis of f. h The relative mRNA expression of Ki67, SP-C, and CCSP was detected by RT-PCR. Data are presented as the mean ± standard deviation (SD). *P < 0.05, ***P < 0.00, assessed by t test. AQP5, aquoporin5; CCSP, club-cell specific protein; α-SMA, anti-alpha smooth muscle actin