Fig 1: Age-related differences in numeric densities of ciliated cells and MUC5AC expression in nasal epithelial cultures from children compared to elderly people. (A, B) Representative images of immunofluorescence of nasal epithelial cultures from healthy children and elderly people. Green: a-tubulin (ciliated cells), magenta: KRT5 (basal cells), yellow: MUC5AC (secretory cells), white: ZO-1 (tight junctions), and blue: Hoechst (cell nuclei). Scale bar, 100 µm. (C–E) Quantification of a-tubulin+ (ciliated) cells (C), KRT5+ (basal) cells (D), and MUC5AC+ (secretory) cells (E) (n = 14 and 11 individuals per group). (F) Transepithelial electrical resistance (TEER) (n = 17 and 14 individuals per group). (G, H) Transcript levels of MUC5AC (G) and MUC5B (H) (n = 16 and 12 individuals per group). (I) Representative MUC5AC and MUC5B Western blot. (J, K) Protein quantification of MUC5AC (J) and MUC5B (K) by densitometry (n = 15 and 11 individuals per group). *p < 0.05 compared to children. Data are shown as mean ± S.E.M. Statistical analysis was performed with unpaired two-tailed t test in (D-F, J), and with two-tailed Mann–Whitney test in (C, G, H, K).