Downregulation of CHOP decreases apoptosis by activation of ER stress-induced autophagy.

<p>(A) Hepa 1–6 cells with or without knockdown of CHOP were treated with TM (0.8 μg/mL) for 24 h. Cells were collected and subjected to western blot analyses with specific antibodies directed against LC3B, Atg5, Beclin1, or β-actin. The density of the corresponding bands was measured quantitatively with an aforementioned method. Each datapoint is the mean ± SD of 3 independent experiments, *<i>P</i><0.05 denotes significant difference from TM-treated Hepa 1–6 cells with normal levels of CHOP. (B) Hepa 1–6 cells underwent the same treatment as in Figure 5A were subjected to flow cytometry assay to detect the expression of LC3B and representative results are shown. Representative experiments were carried out at least three times, **<i>P</i><0.01 denotes significant difference from shCtrl group. (C) Hepa 1–6 cells without or with knockdown of CHOP alone, or combined knockdown of CHOP and LC3B, were treated with TM (0.8 μg/mL) for 24 h. Cells were collected and subjected to western blot analyses with specific antibodies directed against c-PARP or β-actin. The density of the corresponding bands was measured quantitatively with an aforementioned method. Each data point is the mean ± SD of 3 independent experiments, *<i>P</i><0.05 denotes significant difference from normal control Hepa 1–6 cells. (D) Hepa 1–6 cells with or without knockdown of CHOP were treatedt with TM (0.8 μg/mL) for 24 h, or 3-MA for 2 h, and then with TM (0.8 μg/mL) for an additional 24 h and then harvested for western blot analyses with specific antibodies directed against c-PARP or β-actin. *<i>P</i><0.05 or **<i>P</i><0.01 denotes significant difference compared to the TM-treated cells.