Figure 5.

The Nampt inhibitor FK866 reduces neuronal NAD⁺ levels but does not affect Nmnat-mediated axonal protection. A, FK866 (1 μm) treatment of DRG neurons expressing either EGFP or cytNmnat1 reduced NAD⁺ levels by ∼65% within 24 h. Error bars represent SD. B, Axonal degeneration assays were performed using neurons expressing EGFP or cytNmnat1 that were treated with FK866 or DMSO (control). The degeneration indices were calculated. Twelve fields were evaluated for each condition, and each experiment was repeated three times. The degeneration index value ± SD at 24, 48, and 72 h is displayed. *Significant difference (p < 0.001) between neurons expressing cytNmnat1 and those expressing EGFP of the indicated genotypes.