Fig. 7.

TNFα activates the inositol-requiring enzyme1 (IRE1α)/X-box binding protein 1 (XBP1) pathway in airway smooth muscle (ASM) cells in a time-dependent fashion. A: exposure to TNFα for 6, 12, and 24 h (50 ng/mL) significantly increased the ratio of phosphorylated to total IRE1α in ASM cells compared with untreated controls. Representative Western blots are shown. B: exposure to TNFα at different times did not significantly change total IRE1α expression [relative to ribosomal protein S16 (RPS16)} in ASM cells compared with untreated controls. Representative Western blots are shown. C: splicing of XBP1 (relative to RPS16) increased significantly after exposure to TNFα at 12 and 24 h (50 ng/mL) in ASM cells compared with untreated controls. Representative Western blots are shown. Data are presented as medians and interquartile range (IQR) represented as a box-and-whisker plot. Results were analyzed using a 2-way ANOVA. Untreated controls for each time point were performed.