Role of S100A10 in macrophage Plg activation and binding. (A) WT and S100A10−/− (KO) macrophages were incubated with or without uPA (50nM) for 10 minutes at room temperature. Cells were washed and incubated with Plg (0.5μM), in the presence or absence of CpB (5 U/mL), followed by addition of the plasmin substrate S2251. The rate of plasmin generation was measured at 405 nm. Statistical analysis was performed by one-way analysis of variance with Tukey multiple comparisons. Data are percentage of specific binding plus or minus SD of 3 independent experiments. (B) WT and KO thioglycollate-elicited macrophages were cultured in the absence of serum for 2 hours before assay. Cells were incubated with 200nM FITC Plg, either with or without ϵ-ACA (100mM), for 1 hour at 4°C in HBSS containing 1mM MgCl2 and 3mM CaCl2. Plg binding was measured by FACS, excluding cells that were positive for propidium iodide. Statistical analysis was performed by Student t test: ***P < .001; *P < .01. Data are Δ405 nm/sec plus or minus SD of 3 independent experiments.
