Glutathione Peroxidase-1 Suppresses the Unfolded Protein Response upon Cigarette Smoke Exposure

Figure 2

NHBE cells isolated from COPD donors have enhanced ER stress protein responses compared to nonsmokers and smokers. Protein was collected from fully differentiated NHBE cells from nonsmokers (NS), smokers (SM), and COPD (COPD) individuals ( donors per group). (a) Protein expression of ATF6, ATF4, GRP94, GRP78, EDEM, CHOP, and β-actin was examined by immunoblots. Phosphorylation of elF2 and PERK was also determined. (b) XBP1 splicing was examined on XBP1 amplified cDNA from NHBE cells from nonsmoker (NS), smokers (S), and COPD (COPD) individuals. Protein expression of XBP1 and β-actin was examined by immunoblots. (a)-(b) For each blot or gel, every lane represents an individual cell donor. Densitometry analysis was performed of XBP1s from DNA gels and other targets by analyzing immunoblots. XBP1 slicing was scored as percent of XBP1s of total XBP1. Dot plots are represented as densitometry units (DU) of pixel intensity expressed as a ratio to β-actin or total elF2 and PERK. Data are shown as mean ± SEM, where each measurement was performed on 3 independent days on 6 donors/group. denotes value < 0.05, when comparing both treatments connected by a line, determined by 2-way ANOVA with Tukey’s post hoc test (>2 groups).