Figure 1.

iNAMPT acetylation levels decrease in response to fasting in adipose tissue and are associated with eNAMPT secretion in differentiated adipocytes. (A) iNAMPT acetylation levels in brown and white adipose tissues (BAT and WAT) of fed and fasted wild-type female mice at 4–5 months of age. The right panel represents average values from two independent experiments. Relative iNAMPT acetylation levels are normalized to fed values. (B) iNAMPT acetylation levels in differentiated HIB-1B cells. Cells were treated with 5 μM Trichostatin A (T) and 5 mM nicotinamide (N) for 3 hr. M; mock treatment. (C) Reduction of eNAMPT secretion after Trichostatin A (T) and nicotinamide (N) treatment in differentiated HIB-1B cells. Levels of eNAMPT secretion were calculated as described in Materials and Methods. (D) Enhancement of eNAMPT secretion in response to low glucose in differentiated HIB-1B cells and 3T3-L1 cells. Cells were incubated with high glucose (H, 25 mM) or low glucose (L, 5 mM) media in the presence or absence of nicotinamide (N, 5 mM) for 3 hr. Bottom panels in C and D represent average values of three independent experiments. Each value is normalized to values from the mock (C) or the high glucose condition (D). Data were analyzed by the Student’s t test or one-way ANOVA with Fisher’s LSD posthoc test. All values are presented as mean ± SEM. *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001