Age associated changes in human tissue NAD(H) and oxidative stress markers
Oxidative damage occurs with advancing age due to an imbalance between free radical production and cellular antioxidant defense mechanisms. Chronic oxidative stress may be associated with NAD+ depletion and a subsequent decrease in metabolic regulation and cell viability.
In genomic DNA repair, NAD+ is the sole substrate for PARP-1, a DNA binding enzyme activated by reactive oxygen species initiated breaks to the DNA and are critical to repair process.
Although a number of studies have demonstrated elevated levels of oxidative stress mediated damage in aged tissue, to our knowledge, no study has yet reported on changes in human tissue NAD+ levels during the aging process.