Figure 4.

The overexpression of SIRT1 promotes inflammasome activation in response to endotoxin. (A) Quantitative polymerase chain reaction analysis of liver extracts indicates increased expression of TLR and inflammasome components. (B) Western blot analysis showing higher expression of cleaved IL-1β supporting activation of the inflammasome in SIRT^oe livers 6 hours after LPS/GalN. Immunofluorescence showing colocalization (C) of Nlrp3 (red) and CD11b (green), (D) of Nlrp3 (red) and Ly6C (green), and (E) of IL-1β (red) and Ly6C (green) in liver sections from WT and SIRT^oe mice 6 hours after LPS/GalN. Primary hepatocytes and BMDMs from WT mice were exposed to 100 ng/mL of LPS and (F) IL-1β , (G) caspase-1, and (H) Nlrp3 gene expression was analyzed by quantitative polymerase chain reaction showing increased response in BMDMs compared with hepatocytes, which show only a marginal response. Slides were mounted on a solution containing DAPI (blue) staining cell nuclei. n = 5–6 animals/treatment group were analyzed. Values are mean ± SEM. ∗∗P < .01, ∗∗∗P < .001 (WT vs SIRT^oe). (C–E) Representative microscopical images are shown at ×20 magnification. Results from in vitro experiments are representative analysis of n = 3 replicates per timepoint, per cell type. Values are mean ± SEM. ∗P < .05, ∗∗P < .01 (WT vs SIRT^oe).