Glycerol-3-phosphate activates ChREBP, FGF21 transcription and lipogenesis in Citrin Deficiency.

Citrin Deficiency (CD) is caused by inactivation of SLC25A13, a mitochondrial membrane protein required to move electrons from cytosolic NADH to the mitochondrial matrix in hepatocytes. People with CD do not like sweets. We discovered that SLC25A13 loss causes accumulation of glycerol-3-phosphate (G3P), which activates carbohydrate response element binding protein (ChREBP) to transcribe FGF21, which acts in the brain to restrain intake of sweets and alcohol, and to transcribe key genes of lipogenesis.

Oral supplementation with Nicotinamide Riboside treatment protects RGCs in DBA/2J mouse model.

Purpose: The aim of this study was to test whether oral administration of nicotinamide riboside (NR), the nicotinamide adenine dinucleotide (NAD+) precursors, protect retina ganglion cells (RGCs) from neurodegeneration in DBA/2J (D2) mice, which is a widely used mouse model of age-related inherited glaucoma.

Method: Oral NR or NAM administration (NR low dose: 1150mg/kg; NR high dose: 4200mg/kg; NAM low dose group: 500mg/kg; NAM high dose: 2000mg/kg of body weight per day) essentially started when D2 mice were 4 or 9 months old and continued up to 12 months old. Control cohort identically received food/water without NAM or NR.

Cryptic phosphoribosylase activity of NAMPT restricts the virion incorporation of viral proteins.

As obligate intracellular pathogens, viruses activate host metabolic enzymes to supply intermediates that support progeny production. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of salvage nicotinamide adenine dinucleotide (NAD) synthesis, is an interferon-inducible protein that inhibits the replication of several RNA and DNA viruses through unknown mechanisms. Here, we show that NAMPT restricts herpes simplex virus type 1 (HSV-1) replication by impeding the virion incorporation of viral proteins owing to its phosphoribosyl-hydrolase (phosphoribosylase) activity, which is independent of the role of NAMPT in NAD synthesis.

Acute exercise boosts NAD metabolism of human peripheral blood mononuclear cells.

Nicotinamide adenine dinucleotide (NAD) coenzymes are the central electron carriers in biological energy metabolism. Low NAD levels are proposed as a hallmark of ageing and several diseases, which has given rise to therapeutic strategies that aim to tackle these conditions by boosting NAD levels. As a lifestyle factor with preventive and therapeutic effects, exercise increases NAD levels across various tissues, but so far human trials are mostly focused on skeletal muscle.