FIGURE 2.

Gal-3 binding to BV-2 and PC12 cells. (A) rGal-3 was labeled with TAMRA and added to a coculture of BV-2 and PC12 cells for 2 h. Gal-3 bound to many BV-2 cells (arrow a) but to only some PC12 cells associated with BV-2 cells (arrow b) and what appears to be phagocytosed cells within microglia (arrows c and d). Binding was blocked by lactose (lower panels). Scale bar, 50 μm. PC12 cells (B) or BV-2 cells (C) were treated with vehicle, Neu (0.1 U/ml), or Neu plus lactose (Lac; 50 mM) for 1 h, followed by 2 h with labeled rGal-3. Flow cytometry was used to quantify Gal-3 binding (n = 3). (D) PC12 cells were treated with 100 or 500 nM of staurosporine (STS) or vehicle (Veh) for 24 h, TAMRA-labeled rGal-3 was applied to the cells for 2 h, and binding was quantified by flow cytometry. Gal-3 bound more specifically to stressed (+100 nM STS) PC12 cells than to apoptotic PC12 cells (+500 nM STS) (n = 3). **p < 0.01, ***p < 0.001 versus vehicle-treated control cells.