Fig. 5

YVAD inhibits Caspase-1 and XIAP cleavage and lowers IL-1β secretion in RPE. Caspase-1 p20 bands were found under all LLOMe-containing stimulation groups, the intensity of which was reduced by 1 h pre-incubation of YVAD at 20 μM but not 1 μM. Similarly, IL-1β’s secretion was also affected by YVAD inhibition, where 20 μM YVAD reduced more than 30% of secreted IL-1β in primary RPE cell culture supernatants (One-way ANOVA, *p < 0.05). When inflammasome was active, evident by the presence of Caspase-1 p20 band and secreted IL-1β, XIAP was cleaved into a small fragment of ~ 34 kDa in molecular weight. The change of XIAP cleavage level followed that in Caspase-1 p20 and IL-1β