Comprehensive transcriptome analysis of skeletal muscle in the NADS knockout mice.

Nicotinamide adenine dinucleotide (NAD+) is a pivotal molecule involved in various biological processes, including energy production, protein post-translational modification, DNA repair, calcium mobilization, and 5’-capping of mRNA. Accumulating evidence has revealed that NAD+ declines with age by disturbing the balance between its synthesis and degradation. Decreased NAD+ levels result in deterioration of physiological functions in multiple tissues, including the liver, muscle, kidney, and brain. Contrarily, the repletion of NAD+ levels by supplementation of NAD+ precursors have beneficial effects on lifespan, physiological aging, and aging-associated diseases. However, it is unknown whether declined NAD+ levels in young age affect aging processes. Therefore, in this study, to better understand the effect of NAD+ levels on the aging processes, we performed the RNA-sequencing using skeletal muscle samples from young and old wild-type and NAD synthetase (NADS)-deficient mice.