抄録
Nicotinamide adenine dinucleotide (NAD+) is an essential co-factor mediating numerous redox reactions. NAD+ also serves as a substrate for poly(ADP-ribose) polymerase (PARP) and sirtuins, and it regulates various biological processes such as metabolism, DNA repair, gene expression, and stress responses. In living organisms, a balance between NAD+ production and its degradation determines NAD+ levels. Recently, a number of studies have demonstrated that NAD+ levels decline with age and that the deterioration of NAD+ metabolism promotes aging and aging-associated diseases, including metabolic diseases, neurodegenerative disease, and musculoskeletal diseases. Conversely, elevated NAD+ levels in tissues have been shown to exhibit beneficial effects on both physiological and pathological aging. Various approaches, such as the supplementation with NAD+ precursors, the activation of NAD+ biosynthetic pathways, and the inhibition of NAD+ degradation, have been used to increase NAD+ levels in tissues. Nicotinamide riboside (NR) and nicotinamide mononucleotide (NNM) are orally bioavailable NAD+ precursors that have demonstrated beneficial effects on aging and aging-associated diseases in animal models and humans. In this review, the overview of NAD+ metabolism has been introduced and the recent knowledge about NAD+ metabolism in aging has been described.
