FIGURE 6.

SIRT1 regulates RelB expression. A, SIRT1 binds to RelB promoter. THP-1 cells were stimulated with 1 μg/ml of LPS for 0, 1, or 16 h, and chromatin was immunoprecipitated with SIRT1 antibody. The SIRT1-DNA complex was analyzed by standard PCR using TNF-α promoter-specific or RelB promoter-specific primers. IgG-immunoprecipitated samples served as negative control. B and C, inhibition of SIRT1 deacetylase activity decreases LPS-induced RelB gene transcription and protein expression during the development of endotoxin tolerance. THP-1 cells were pretreated for 1 h with 1 μm Ex527 followed by stimulation with 1 μg/ml of LPS for indicated times. RelB mRNA was quantified by real-time PCR and RelB protein levels were analyzed using Western blot. RelB mRNA levels are presented as fold changes relative to unstimulated control. Ctrl, control; med, medium.