The expression of genes and proteins related to the NAcht Leucine-rich repeat Protein 3 (NLRP3) inflammasome, including NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), caspase-1 and its activated forms, and the inflammatory factor interleukin-1β (IL-1β) and its activated forms were measured.
NLRP3 and ASC-speck protein expression was analyzed by FlowSight AMNIS, whereas production of the pro-inflammatory cytokines IL-1β and IL-18 and of caspase-1 and caspase-8 was measured by ELISA in supernatants.
A neutrophil elastase inhibitor blocked ASC inflammasome-independent production of IL-1β and the IL-1 receptor antagonist, anakinra, confirmed that IL-1 remains crucial to the clearance of bacteria during superinfection.
Western blot was used to detect the expression of key proteins in inflammatory signaling cascades including toll-like receptor 4 (TLR4), myeloid differentiation protein 88 (MyD88), nuclear factor-kappa B (NF-κB), Nod-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), cysteinyl aspartate specific proteinase-1 (Caspase-1) and IL-1β, as well as insulin signaling in liver and prefrontal cortex of rats.