Fig. 2

Overview of NAD+ metabolism pathway. NA: nicotinic acid, NAM: nicotinamide, QA: quinolinic acid, NMN: nicotinamide mononucleotide, NR: nicotinamide riboside, IDO, indoleamine 2,3-dioxygenase, TDO, tryptophan 2,3-dioxygenase, KMO, 3-hydroxykynurenine (3-HK) by kynurenine 3-monooxygenase, KYNU, tryptophan 2,3-dioxygenase, 3HAO. 3-hydroxyanthranilic acid oxygenase, ETC, NAMN: nicotinic acid mononucleotide, NAD: Nicotinamide adenine dinucleotide, NADH: reduced form of NAD, NADP: Nicotinamide adenine dinucleotide phosphate, NADPH: reduced form of NADP, NAAD: nicotinic acid adenine dinucleotide, NAMPT: nicotinamide phosphoribosyltransferase, NMNAT: nicotinamide mononucleotide adenylyltransferase, QPRT: quinolinic acid phosphoribosyltransferase, NaPRT: nicotinic acid phosphoribosyltransferase, Nrk: nicotinamide riboside kinase, NADS: NAD synthase, PARP: poly (ADP-ribose) polymerase, TCA, tricarboxylic acid, ETC, electron transport chain