NAD+-Consuming Enzymes in Stem Cell Homeostasis

Abstract

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.

Cystine/glutamate antiporter xCT controls skeletal muscle glutathione redox, bioenergetics and differentiation

“…Of note, decreases NAD + availability and increases in NADH can promote cellular senescence in stem cells due to lower NAD + availability to support NAD + -dependent enzymes ( e.g. sirutins) and is associated with lower mitochondrial quality and biogenesis [ [91] , [92] , [93] ]. Thus, while the observed complex I dysfunction may not be related to the immediate availability of NADH for oxidation, decreases in NAD + may contribute to the impaired myoblast proliferation and exercise bioenergetic adaptation phenotype in the Slc7a11 sut/sut mice [ 6 ].…”