Figure 4. Nampt and NMN increase NAD level and ameliorate NAD depletion.

Human islets (A) and INS-1E cells (B) were stimulated with NMN [100 µM] or Nampt [2.5 ng/ml] for a short time (2 or 3 h) or a long time exposure (48 h). NAD level were normalised to the total protein amount in each sample. FK866 [10 nM], a specific Nampt inhibitor, was used as a positive control in INS-1E cells. * p<0.05 compared to con (serum free medium);+p<0.05 compared to FK866 treated cells.