%20is%20essential%20for%20energy%20metabolism%20and%20many%20cell%20signaling%20processes,%20but%20because%20it%20is%20constantly%20used%20and%20broken%20down,%20cells%20must%20continuously%20r...){kind=link}
Nicotinamide Riboside and Nicotinic Acid Riboside Production in Human Cells: Preclnical Findings
Synopsis
Nicotinamide adenine dinucleotide (NAD+) is essential for energy metabolism and many cell signaling processes, but because it is constantly used and broken down, cells must continuously rebuild it. This study explored how human cells generate two key NAD+ precursors — nicotinamide riboside (NR) and nicotinic acid riboside (NAR). Researchers found that specific human enzymes, cytosolic 5′-nucleotidases (CN-II and CN-III), can convert other NAD+ intermediates into NR and NAR, similar to how yeast cells perform this process. When these enzymes were overexpressed in human cell lines, the cells produced and released measurable amounts of NAR, which could even support neighboring cells that could not make their own NAD+. The findings show that human cells can both produce and share NAD+ precursors, suggesting that NR and NAR are natural components of human metabolism and may help maintain cellular energy balance across tissues.
Journal
Journal of Biological Chemistry