Fig. 1.

Mutant SOD1 activates caspase-1 in microglia and macrophages. (A–E) Primed cells were stimulated with 10 μM or the depicted concentrations of WT or G93A-SOD1 for 20 h or as indicated. (A) Flow cytometry analysis of caspase-1 activation in primary microglia by a fluorescent cell-permeable inhibitor that binds to active caspase-1 (FLICA). Numbers above bracketed lines indicate percentage of cells with active caspase-1. Unstimulated and ATP-stimulated cells served as controls. (B) Immunoblot analysis of cell lysates and supernatants of stimulated bone marrow–derived macrophages (BMMs) with antibodies to the p10 subunit of caspase-1 and to IL-1β, respectively. Actin shows equal loading of lanes. (C–E) ELISA analysis of secreted, mature IL-1β in the cell supernatant of stimulated primary microglia (C), caspase-1–deficient BMMs (D), or primary astrocytes (E). Data are representative of at least three independent experiments; error bars represent SEM of triplicate wells.