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 the regulation of the NAD-consuming enzymes.