Effect of inhibiting RLC phosphorylation stimulated by anti-β₂GPI antibodies on endothelial microparticle release and cell surface E-selectin expression. Endothelial cells were incubated in medium alone or with β₂GPI and control or anti-β₂GPI antibodies for 8 hours and the release of microparticles and cell surface expression of E-selectin quantified as described in “Materials and methods.” Inhibitors used include Y-27632 (5 µM), ML-7 (5 µM), or blebbistatin (50 µM). Inhibitors were used alone or in combination, as depicted in abscissa of each graph. (A,C,E,G) The effects of inhibitors or specific siRNA on endothelial cell microparticle release induced by anti-β₂GPI antibodies. (B,D,F,H) The effects of inhibitors or specific siRNA on endothelial E-selectin expression induced by anti-β₂GPI antibodies.