Figure 11

Effect of Caspase-1 inhibition on NOS2 activity. Microglia were incubated with 1 ng/ml LPS and the indicated concentrations of the caspase-1 cell-permeable irreversible inhibitor, Ac-YVAD-CMK. After 4 hr, (A) IL-1β levels in the incubation media were assessed by ELISA; and (B) NOS2 activity in the cells measured by increase in net DCF fluorescence (total RFU minus the RFU obtained by preincubating cells with 100 μM AMT NOS2 inhibitor). The data are means ± s.e.m of 3 experiments; the values for IL-1β are presented as % of the response to LPS alone (100% = 2520 ± 150 pg/ml). ***, P < 0.001 versus LPS alone. (C) Caspase-1 deficient microglia were incubated in 1 μg/ml LPS with 0 or 10 μM NE. Nitrite levels were measured after 24 hours. Data are means ± s.e.m. of 3 experiments. ***, P < 0.001 versus LPS alone.