Fig. 1.

ER stress-induced UPR in tunicamycin-treated human THP-1 monocytes. Protein levels of markers of ER stress-induced UPR, namely p-eIF2α (A), ATF4 (B), IRE1α (C), XBP1s (D), GRP78 (E) and CHOP (F) were quantified by WB in total cellular extracts obtained from human THP-1 monocytes treated with 5 or 10 μg/mL tunicamycin (TM) during the indicated time periods (1–24 h). β-Tubulin I was used to control protein loading and to normalize the levels of the protein of interest. For p-eIF2α quantification, total eIF2α was used as a protein loading control. Results were calculated relatively to control values and represent the mean ± SEM of at least three independent experiments. Statistical significance between control (untreated cells) and TM-treated cells was determined using the one-way ANOVA test, followed by the Dunnett’s post hoc test: *p < 0.05; **p < 0.01; ***p < 0.001, ****p < 0.0001