Figure 4. Involvement of ctsB in FSS-induced neutrophil detachment.

(A and B) Representative images depicting shear-induced neutrophil detachment from platelet (A) or HUVEC (B) monolayers in response to 5 dyn/cm² shear stress exposure during a 10-min period. Neutrophils were left UNT or treated with ctsB-specific inhibitor CA074-me (50 µM) or serine inhibitor AP (5 μM). (C and D) The number of neutrophils remaining adherent to platelet (C) or HUVEC (D) monolayers after 10 min of shear exposure was normalized to the initial number of adherent neutrophils before shear exposure and plotted as means ± sd, based on counts manually performed using ImageJ software. Neutrophils were left UNT or pretreated for 5 min with inflammatory agonist fMLP (1 μM), serine inhibitor AP (5 μM), ctsB-specific inhibitor CA074-me (50 μM), or cysteine inhibitor E64 (30 μM). n = 4 replicates in each group. *P < 0.05 compared with control; #P < 0.05 compared with AP. Scale bars are 100 µm.