Figure 3

Surfactant protein D, Mucin 5AC and cytokeratin-5 expression in ALI cultures at different differentiation stages. SP-D, MUC5AC, and CK-5 expression were examined in ALI sections grown for 7, 14, and 21 days from non-asthmatic donors via immunohistochemistry, where pink was indicative of positivity [A]. Fraction of total epithelial area positive was quantified using colour segmentation in ImagePro Plus. Expression of SP-D in the airway epithelia decreased significantly as the cultures differentiated from day (d) 7 to 21 (n = 5, one-way ANOVA p = 0.004) [B]. SP-D protein expression in 7, 14, and 21-day ALI cultures were detected by Western blotting, quantified by densitometry relative to cultures at 0 days. A linear trend was observed (n = 3, p = 0.04) [C]. Expression of MUC5AC in the airway epithelia increased significantly as the cultures grew from day 7 to 21 as demonstrated by immunohistochemistry (n = 4, one-way ANOVA p = 0.007) [D]. Expression of CK-5 in the airway epithelia decreased significantly as the cultures grew from day 7 to 21 (n = 4, one-way ANOVA p = 0.002) [E].