The role of three UPR sensors in MMC-induced apoptosis in fibroblasts.

<p>Fibroblasts were transfected with the PERK, ATF6, IRE1 or non-targeting lentiviral-mediated shRNAs. (A) The expression levels of the targeted transcripts were determined by Western blotting with PERK, ATF6, IRE1 and β-actin antibodies. The presented data represents the results of two independent experiments. (B) Transfected cells were treated with MMC as described in the text and then cell viability was measured after 48 hours. (C) Apoptosis rates were determined via Annexin V/propidium iodide double staining and are shown in the bar graph. (D) After MMC treatment (0.4 mg/ml, 5 minutes) and incubation for 48 hours, equal amounts of the whole cell lysates were analyzed by Western blotting with antibodies specific for CHOP, BIM, cleaved caspase-3, and β-actin (loading control). This experiment was performed in triplicate. The data presented in panels B and C are the mean ± SD of three independent experiments, *P<0.05, ***P<0.001.