NAD in Aging: Molecular Mechanisms and Translational Implications.

The coenzyme NAD is critical in cellular bioenergetics and adaptive stress responses. Its depletion has emerged as a fundamental feature of aging that may predispose to a wide range of chronic diseases. Maintenance of NAD levels is important for cells with high energy demands and for proficient neuronal function. NAD depletion is detected in major neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases, cardiovascular disease and muscle atrophy. Emerging evidence suggests that NAD decrements occur in various tissues during aging, and that physiological and pharmacological interventions bolstering cellular NAD levels might retard aspects of aging and forestall some age-related diseases. Here, we discuss aspects of NAD biosynthesis, together with putative mechanisms of NAD action against aging, including recent preclinical and clinical trials.