The effect of C1INH on LPS-induced endothelial cell apoptosis. HUVECs were incubated with LPS (175 ng/mL) in the presence or absence of C1INH (150 μg/mL). (A) Isolated DNA from HUVECs was resolved on a 1.5% agarose gel and stained with ethidium bromide, and was then visualized by ultraviolet (UV) light. DNAmolecular weight markers, expressed as base pair (bp), are indicated to the left of lane 1 on the gel. (B) The binding of FITC-conjugated annexin V to apoptotic cells was analyzed on a FACS Calibur (FITC–annexin V binding, thick line; control, shaded field).