Nicotinamide adenine dinucleotide metabolism in the immune response, autoimmunity and inflammageing

Metabolism is dynamically regulated to accompany immune cell function, and altered immunometabolism can result in impaired immune responses. Concomitantly, the pharmacological manipulation of metabolic processes offers an opportunity for therapeutic intervention in inflammatory disorders. The nicotinamide adenine dinucleotide (NAD+) is a critical metabolic intermediate that serves as enzyme cofactor in redox reactions, and is also used as a co-substrate by many enzymes such as sirtuins, adenosine diphosphate ribose transferases and synthases. Through these activities, NAD+ metabolism regulates a broad spectrum of cellular functions such as energy metabolism, DNA repair, regulation of the epigenetic landscape and inflammation. Thus, the manipulation of NAD+ availability using pharmacological compounds such as NAD+ precursors can have immune-modulatory properties in inflammation. Here, we discuss how the NAD+ metabolism contributes to the immune response and inflammatory conditions, with a special focus on multiple sclerosis, inflammatory bowel diseases and inflammageing