%20is%20vital%20for%20enzymes%20like%20sirtuins%20and%20PARPs,%20which%20help%20cells%20repair%20DNA%20double-strand%20breaks%20(DSBs)%E2%80%94a%20severe%20type%20of%20genetic%20damage%20caused%20by%20ra...){kind=link}
Impact of Nicotinamide Riboside on DNA Repair: Preclinical Findings
Synopsis
Nicotinamide adenine dinucleotide (NAD+) is vital for enzymes like sirtuins and PARPs, which help cells repair DNA double-strand breaks (DSBs)—a severe type of genetic damage caused by radiation. This study tested whether changing NAD+ levels affects DNA repair in human skin fibroblasts exposed to moderate ionizing radiation (IR). Supplementing cells with nicotinamide riboside (NR), a compound that raises NAD+ levels, did not improve DNA repair efficiency after exposure to 1 or 5 gray (Gy) of radiation. Even when NAD+ was almost completely depleted using an inhibitor, cells could still repair most DNA breaks, although key repair signals like ATM kinase activation were weakened. These findings suggest that while NAD+-dependent enzymes support DNA repair, they are not absolutely essential for recovering from moderate radiation-induced damage.
Journal
Cells