Virulence Factors of Pseudomonas aeruginosa Induce Both the Unfolded Protein and Integrated Stress Responses in Airway Epithelial Cells
Fig 2
P. aeruginosa secreted virulence factors induce ER stress in primary bronchial epithelial cells.
A. Time-dependent induction of ER stress in primary bronchial epithelial cells, as assessed by XBP1 splicing, CHOP and GADD34 mRNA after treatment with CM-PAO1 (n = 5; mean ± SEM). B. Dose-response of spliced XBP1, CHOP and GADD34 mRNA in primary bronchial epithelial cells treated with CM-PAO1 for 12 hours (n = 5; mean ± SEM). C. Time-dependent phosphorylation of eIF2α (p-EIF2α) and synthesis of GADD34 and GRP78 (visualised with anti-KDEL antibody). Relative quantifications for each protein are shown within; representative of n = 3). D. Time-dependent decrease of puromycin incorporation in nascent proteins. Total eIF2α and β-actin serve as loading controls. * p<0.05, ** p<0.01, ***p<0.001 versus control (ctrl) with two-way repeated-measurements ANOVA (Bonferroni post-hoc) or untreated (-) with a one-way repeated-measurements ANOVA (Bonferroni post-hoc).