Figure 2.

Stx1, Stx2, and histones induce changes in aortic endothelial expression of surface molecules. Human aortic endothelial cells were challenged with 50 μg/mL histones (A,C,E) or 100 ng/mL Stx1 (B,D,F) and surface expression of PAR-1, EPCR, and TM were quantified by flow cytometry using antigen-specific antibodies. Histogram overlays show representative staining of unchallenged cells (gray) and challenged cells (dark) compared to background staining (unfilled), with challenges represented using Stx1, as there were no differences in effect with respect to which Shiga toxin was used. Bar graphs show geometric means ± SD of three to four experiments each, except (B), which compares the M1 region 1, expressed as a percentage. Differences from constitutive expression (media only = 100%) are shown as ***p < 0.001.