NADrelated

NADrelated refers to topics associated with nicotinamide adenine dinucleotide (NAD) and its biochemical context. In practice, the term encompasses NAD+, NADH, NADP+, NADPH, and the networks that govern their metabolism, redox chemistry, and signaling.

NAD+ functions as a central redox cofactor in catabolic and energy-producing reactions, accepting electrons to form NADH during glycolysis and the tricarboxylic acid cycle, and then being reoxidized to NAD+ in the mitochondrial electron transport chain. The NAD+/NADH ratio influences metabolic flux and energy production. NADP+/NADPH serves mainly in anabolic reactions and in maintaining redox balance, providing reducing equivalents for biosynthesis and antioxidant defenses.

Biosynthesis and salvage: NAD can be synthesized de novo from tryptophan, via the Preiss-Handler pathway from nicotinic acid, and through salvage pathways from nicotinamide, nicotinamide riboside, and nicotinamide mononucleotide (NMN). Key enzymes include NAMPT (nicotinamide phosphoribosyltransferase), NMNATs (nicotinamide mononucleotide adenylyltransferases), and NAPRT. Dietary precursors such as NR (nicotinamide riboside) and NMN are studied as NAD+-boosting agents.

NAD+-dependent enzymes and signaling: Sirtuins (SIRT1–7) regulate transcription, metabolism, and stress responses; poly(ADP-ribose) polymerases (PARPs) participate in DNA repair; CD38 degrades NAD+; SARM1 consumes NAD+ during axon degeneration. These enzymes link cellular energy status to gene expression, repair, and signaling.

NADrelated research and applications: Areas include aging, mitochondrial function, metabolism, and cellular signaling. Therapeutic interest centers on strategies to elevate cellular NAD+ levels through precursors and small molecules to support metabolic health and neuroprotection, with ongoing preclinical and clinical investigations.