Promega, G9951, Caspase-Glo® 1 Inflammasome Assay

Caspase-1 Activity is Distinguished From Other Caspases
Inflammation and apoptosis caspases at equimolar concentrations were tested with the assay, +/– Ac-YVAD-CHO, and caspase activity was measured after 20 minutes. Ac-YVAD-CHO at 1µM inhibited 99% of the caspase-1 activity, whereas it had minimal effect on the other cross-reacting caspases (5, 3 and 6).
NLRP3 Inhibitor Prevents Caspase-1 Activation in THP-1 and PBMC Cells
NLRP3 plays a key role in immune sensing by initiating the assembly of an inflammasome in response to various danger signals. The NLRP3 inflammasome triggers caspase-1 activation and IL-1β cytokine secretion, eventually resulting in an inflammatory, pyroptotic cell death. The Caspase-Glo® 1 Assay allows you to easily measure the effect of NLRP3 inhibitors on caspase-1 activation in primary cells.
THP-1 cells were differentiated for 3 days with PMA. Medium was replaced and MCC950 (NLRP3 inflammasome inhibitor), was added followed by LPS or vehicle. Half of the culture medium (50µl) was removed after 3 hours of LPS and tested with Caspase-Glo ® 1 Reagent or Caspase-Glo ® 1 Reagent + YVAD-CHO.
PBMCs were plated, then treated with MCC950 followed by LPS or vehicle overnight. Following the overnight treatment, cells were treated with nigericin or vehicle. Nigericin causes potassium efflux and significant caspase-1 activation after LPS priming. Half of the culture medium (50µl) was then removed and tested with Caspase-Glo ® 1 Reagent or Caspase-Glo ® 1 Reagent + YVAD-CHO. Luminescence was read for both after 1 hour. Caspase-Glo® 1 signal demonstrates a dose-dependent inhibition of caspase-1 activity by the NLRP3 inflammasome inhibitor.
Caspase-1 Activity Detected in Peripheral Blood Mononuclear Cells and Released into Medium
Caspase-Glo® 1 Inflammasome Assay monitors caspase-1 activity in peripheral blood mononuclear cell (PBMC) supernatant. Cells were stimulated with or without LPS then subsequently stimulated with ATP for 30 minutes. Cells were then pelleted and supernatant was assayed for caspase-1 activity.