Figure 1.
HDLs prevent oxLDLs-triggered UPR/ER stress activation in HMEC-1 cells and caspase-12 processing in mouse endothelial cells. Time course of phosphorylation of IRE1α and eIF2α in HMEC-1 cells treated with oxLDLs (200 μg ApoB/ml) or pre-incubated with HDLs (200 μg ApoA/ml) for 1 h. Cell lysates were assessed for phospho-IRE1α (a) and phospho-eIF2α (b) protein expression by western blot analysis, β-actin expression was used as protein loading control. (c) Immunocytochemistry experiments show the cytoplasmic and nuclear translocation of ATF6 in HMEC-1 cells treated with oxLDLs (200 μg ApoB/ml) for 16 h or pre-incubated with HDLs (200 μg ApoA/ml) for 1 h. These data are representative of three separate experiments. (d) Real-time PCR experiments showing mRNA expression of human spliced form XBP1 (sXBP1) in HMEC-1 cells treated with oxLDLs (200 μg ApoB/ml) for 16 h or pre-treated with HDLs (200 μg ApoA/ml) for 1 h, relative mRNA levels were normalized to GAPDH mRNA. The data are expressed as mean±S.E.M. of four separate experiments, *P<0.05 indicates significance (comparison between OxLDL and OxLDL+HDL groups). (e) Processing of procaspase-12 in mouse endothelial cells treated with oxLDLs (100 or 200 μg ApoB/ml) or pre-incubated with HDLs (200 μg ApoA/ml) for 1 h. Cell lysates were assessed for caspase-12 protein expression by western blot analysis, β-actin expression was used as protein loading control. Blots are representative of three independent experiments