Addition of S100A10, but not annexin A2, increases invasion of S100A10−/− macrophages. (A) WT and S100A10−/− (KO) peritoneal macrophages (1 × 105 cells) were added to the upper chamber of Matrigel-coated chambers (BD Biocoat chambers, 8-μm pore), which contained Plg and S100A10, annexin A2, or bovine serum albumin (2 μg/mL). The lower chamber contained MCP-1 (10 ng/mL). Cells were incubated at 37°C for 48 hours. Invading cells were quantified as described in “Matrigel invasion and cell migration.” Data are expressed as mean number of cells per 40× field plus or minus SD of 3 independent experiments. Statistical analysis was performed by one-way analysis of variance (with Tukey multiple comparisons) compared with Plg-dependent S100A10−/− invasion: ***P < .001. ns indicates not significant. (B) Flow cytometric analysis of cell-surface annexin A2 and S100A10 levels in WT and S100A10−/− (KO) peritoneal macrophages. Macrophages were incubated in the presence or absence of annexin A2 (2 μg/mL) or S100A10 (2 μg/mL), washed, and incubated with antiannexin A2 and anti-S100A10 antibodies. Black line indicates staining with anti–annexin A2 or anti-S100A10 antibodies; and light gray area, the reaction with nonimmune rabbit IgG.
