NAD + -Consuming Enzymes in Stem Cell Homeostasis.

Nicotinamide adenine dinucleotide (NAD + ) is a coenzyme used in redox reactions, energy metabolism, and mitochondrial biogenesis. NAD + is also required as a cofactor by nonredox NAD + -dependent enzymes. Hundreds of enzymes that consume NAD + have been identified. The NAD + -consuming enzymes are involved in a variety of cellular processes such as signal transduction, DNA repair, cellular senescence, and stem cell (SC) homeostasis. In this review, we discussed how different types of NAD + -consuming enzymes regulate SC functions and summarized current research on the roles of the NAD + consumers in SC homeostasis. We hope to provide a more global and integrative insight to the mechanism and intervention of SC homeostasis via the regulation of the NAD + -consuming enzymes.