Lyn regulated IL-13-induced ER stress and MUC5AC expression. (a) Representative immunohistochemical staining for IL-13 in the lungs (original magnification: 200 ×). (b) IL-13 levels in the lung tissue were determined by ELISA in triplicate lung lysate samples from each animal. (c–e) 16HBE cells were stably transfected with control (CTRL) lentiviral or Lyn lentiviral, respectively. Representative confocal laser immunofluorescence photomicrographs of MUC5AC, BIP and CHOP expression in cells (original magnification: 400 ×). (f) Quantitation of the fluorescence intensity of MUC5AC, BIP and CHOP in 10 random fields. (g) Representative Western blots of phospho-PI3K p85α, PI3K p85α, phospho-Akt1, Akt1, phospho-NFκB p65 (Ser536), NFκB p65, Lyn, β-actin, BIP, CHOP, and phospho-Lyn (Tyr416) in cells. (h) Relative change in density of phospho-Lyn and β-actin, phospho-PI3K p85α and PI3K p85α, and phospho-Akt1 and Akt1, as measured by Western blot. Data are representative of three experiments. Bars represent the mean ± s.d (n = 8 each group, one-way ANOVA with Tukey-Kramer post-test).