Figure 1

HDM induces ER stress and activation of caspase-3 in primary human nasal (PHNEs) and bronchial epithelial cells (HBE). PHNEs from two subjects and HBEs were treated with HDM for the indicated time. The cell lysates were subjected to western blot analysis to detect ER stress markers (A). Caspase-3 activity was measured using a luminescence assay (B). * indicates p < 0.05 as compared to their PBS controls by ANOVA from 2 experiments in triplicate. HBE cells were transfected with siRNA for ATF6α or a non specific Scr sequence, challenged with HDM, and subjected to western blot analysis to detect ER stress markers (C). Caspase-3 activity was measured using a luminescence assay (D). Cell death was quantified using MTT assay (E). * indicates p < 0.05 as compared to their respective PBS controls. # indicates p < 0.05 as compared to their siRNA transfected HDM challenged samples (by ANOVA).