Fig. 3

Effect of silencing KRAS expression on regulation of basal cell (BC) differentiation into a mucociliated epithelium. Primary human airway BC were untreated or transfected with either control, or KRAS specific siRNA and cultured on ALI for 14 days to assess the impact of KRAS on BC differentiation into a mucociliated epithelium. a Immunofluorescence staining of KRT5⁺ BC. Sections of cells on ALI day 14 stained for KRT5 (red) and DAPI (nuclei, blue). b Alcian blue staining of secretory cells. Sections of cells on ALI day 14 stained with Alcian blue (blue). c Immunofluorescence staining of MUC5B⁺ secretory cells. Sections of cells on ALI day 14 stained for MUC5B (red) and DAPI (nuclei, blue). d Immunofluorescence staining of SCGB1A1⁺ secretory cells. Sections of cells on ALI day 14 stained for SCGB1A1 (red) and DAPI (nuclei, blue). e Immunofluorescence staining of β-tubulin IV⁺ ciliated cells. Sections of cells on ALI day 14 stained for β-tubulin IV (green) and DAPI (nuclei, blue). f Immunofluorescence staining of IVL⁺ squamous cells. Sections of cells on ALI day 14 stained for IVL (red). The data for a-f are the mean percentage of positively stained cells for n = 3 independent experiments performed with independent donors of BC. Error error bars indicate standard error of the mean. ANOVA was used to determine the statistical significance among groups as described in the methods section. Scale bar 20 μm