FIGURE 8.

γKA-PE induces elements of the ER stress response. HUVEC were treated with 3 μm PE or γKA-PE for 10–60 min, lysates generated, and induction of three representative elements of the ER stress response measured by immunoblotting as described under “Experimental Procedures.” A, immunoblots for BiP/grp78, phospho-p38, CHOP, and actin from a representative experiment. Actin was used as an internal loading control for each sample. B, quantitation of three replicate CHOP immunoblotting experiments. For each replicate, sample was normalized to the 10-min PE treatment to determine fold increase in expression. C, quantitation of three replicate BiP immunoblotting experiments. D, quantitation of three replicate phospho-p38 experiments. E, immunoblot for phospho-p38 and total p38 after 60 min of incubation with 3 μm PE or γKA-PE in additional experiments to determine whether increased phospho-p38 expression resulted from increased total p38 expression or increased phosphorylation. Samples were in nonadjacent wells on same membrane. F, quantitation of duplicate phospho-p38 and total p38 immunoblotting experiments.