Fig. 6

ATP repletion, colchicine-triggered apoptosis, and caspase activity in CGC treated with GSNO or MPP⁺. (A) Medium of CGC was supplemented with glucose (10 mM) or not. Neurons were then treated with colchicine (1 µM). GSNO (100 µM) or MPP⁺ (50 µM) was added to the cultures 8 hr after colchicine. ATP was measured 9.5 hr after addition of colchicine (1.5 hr after MPP⁺/GSNO); caspase activity and apoptosis were quantitated after 18 hr exposure to colchicine (8.5 hr after MPP+/GSNO). As a control, neurons were incubated with colchicine alone. Data from this incubation (see Fig. 4) were used as 100% reference values. All data shown are expressed as percentage of colchicine-alone values and are means from three different experiments. (B) CGC were incubated in the absence or presence of glucose and of different inhibitors as described above. After 18 hr, cell lysates were prepared and analyzed by Western blot for caspase-3 processing. Recombinant caspase-3 was used as standard.