[DDX10 promotes AIM2-inflammasome activation by maintaining AIM2 protein stability]

Objective To investigating the role of DEAD box helicase 10 (DDX10) in regulating absent in melanoma 2 (AIM2)-inflammasome activity. Methods HEK293T-caspase-1-ASC-IL-1β (HEK293T-CIA) cells were transiently co-transfected with expression vector carrying AIM2 and one of the 10 candidate genes encoding DDX family members. To screen candidate regulators of AIM2 inflammasomes, cell culture supernatants were collected to measure IL-1β release by ELISA. For AIM2 inflammasome activation, DDX10^-/- THP-1 cells were first differentiated into macrophages by phorbol-12-myristate-13-acetate (PMA) induction, followed by LPS priming and poly(dA: dT) stimulation. The expression of pro-caspase-1, cleaved-caspase-1 and DDX10 were measured by Western blot analysis. The interaction between DDX10 and AIM2 was confirmed by immunoprecipitation. DDX10 and AIM-2 co-localization in HEK293T cells was confirmed by immunofluorescence cytochemistry combined with confocal microscopy. Results Overexpression of DDX10 enhanced AIM2-induced inflammasome activation, while DDX10 deficiency inhibited AIM2 inflammasome activation. Mechanistically, DDX10 interacted with HIN-200 domain of AIM2 and stabilized the protein expression. Conclusion DDX10 promotes AIM2 inflammasome activation by stabilizing AIM2.