Flow chamber analysis of the contribution of TNF-α signaling to platelet attachment to HUVECs. (A-B) Attachment of human platelets to cultured HUVECs. Some cells were treated with si-TNF-R1 48 hours before the experiments; CTRL denotes HUVECs treated with control scrambled si-RNA. Some cells were also treated with human rTNF-α (24 hours, 10 ng/mL). After perfusing tetramethylrhodamine ethyl ester–stained platelets with Tyrode buffer for 5 minutes at 200 dynes/cm2, adherent platelets were visualized (A). White arrows denote the direction of flow. The numbers of adherent platelets were quantified and normalized to the number obtained using CTRL cells (B). AU denotes arbitrary units. (n = 15 experiments for each group). Asterisks indicate statistical significance (P < .05). Scale bar is 10 μm.
