Virulence Factors of Pseudomonas aeruginosa Induce Both the Unfolded Protein and Integrated Stress Responses in Airway Epithelial Cells
Fig 5
The P. aeruginosa secreted virulence factors alkaline protease (AprA) and pyocyanin mediate ER stress.
A. Western blot analysis of conditioned medium (CM) of strains PAO25, PAN8 and PAN11 for AprA (representative of n = 2; complete blot is shown in S3B Fig). Equal volumes of the conditioned medium were loaded onto the gel. AprA displays 200 nM purified AprA and serves as a positive control. B. Normalised expression levels of XBP1 splicing, CHOP, GADD34 and GRP78 mRNA in 16HBE cells after stimulation with CM-PAO25, CM-PAN8 or CM-PAN11 (n = 3; mean ± SEM). All values are normalised to the housekeeping genes RPL13A and ATP5B. C. Normalised expression values of spliced XBP1, CHOP, GADD34 and GRP78 mRNA in 16HBE cells after stimulation with 10 nM purified AprA. All values are normalised to the housekeeping genes RPL13A and ATP5B. * p<0.05, ** p<0.01, ***p<0.001 versus untreated (-) with a one-way repeated-measurements ANOVA (Bonferroni post-hoc).