Wednesday, November 13, 2019
Nicotinamide adenine dinucleotide (NAD+)
Nicotinamide adenine dinucleotide (NAD+) is a coenzyme required for mitochondria to produce energy. NAD+ levels are one way for energy to be circulated within the cell, and levels rise while fasting and decrease during aging. A group of enzymes called sirtuins rely on NAD+ to exert their beneficial activities, functioning less well as levels decline. Other NAD+ dependent enzymes also function less efficiently with aging. NAD+ supplementation is a preliminary approach to replenish the NAD+ levels lost to aging. The reason NAD+ levels decline with aging is currently unknown. One hypothesis is that DNA repair enzymes, known as PARP (poly ADP-ribose polymerase), might be using up more NAD+ to fix the accumulated DNA damage that occurs with age. Alternately, the cellular pathway that recycles NAD+ may decline in performance with age. In this clip, Dr. Eric Verdin explains how nicotinamide adenine dinucleotide levels diminish with age and describe the ongoing research to understand the reasons why.