Figure 8.

Nampt potentiates metabolic ability. (A) Nampt knockdown suppresses mitochondrial proteins during HFD consumption. Heart lysates were prepared from WT and Nampt^+/− mice after 3 months of HFD consumption. Western blot analyses were performed with indicated antibodies. (B-D) Nampt potentiates ATP production and fatty acid oxidation. Cardiomyocytes were transduced with shNampt. Oxygen consumption rate was examined in cardiomyocytes incubated with 100 μmol/L palmitic acid (PA). ATP production coupled oxygen consumption (C) and maximum fatty acid oxidation capacity (D) are shown. (C-D) N=5–6. (E) Western blot showing knockdown of Nampt by adenovirus vector of shNampt. (F-G) Cardiomyocytes were transduced with Ad-Nampt. Oxygen consumption rate was examined in cardiomyocytes incubated with 100 μmol/L palmitic acid (PA). Statistical significance was determined with ANOVA (A), the Kruskal-Wallis test (C), the Mann-Whitney U test (G), and the Student’s t test (G). (H) A schematic representation of the current hypothesis. Nampt promotes NAD production, which promotes NADP production via NADK. Increased NADP(H) confers resistance against oxidative stress, possibly through the GSH and Trx systems, which may in turn attenuate diastolic dysfunction.