NAD+ as a Senolytic and Anti-Aging Molecule

Ball and Stick Model for NAD+ A Molecule

Fisetin Molecule (above) Ball-and-stick. For 3D Jsmol File

Molecular formula

Molar mass

NAD+ molecular structure

NAD+ BOOSTER CALLED NMN -- ANTI-AGING PROPERTIES - BUT POSSIBLE PROINFLAMMATORY PROPERTIES

Research article published in Science Journal (sede below) the team identifies a critical step in the molecular process that allows cells to repair damaged DNA. Their experiments in mice suggest a treatment is possible for DNA damage from ageing and radiation. It is so promising it has attracted the attention of NASA, which believes the treatment can help its Mars mission.While our cells have an innate capability to repair DNA damage -- which happens every time we go out into the sun, for example -- their ability to do this declines as we age. The scientists identified that the metabolite NAD+, which is naturally present in every cell of our body, has a key role as a regulator in protein-to-protein interactions that control DNA repair. Treating mice with a NAD+ precursor, or "booster," called NMN improved their cells' ability to repair DNA damage caused by radiation exposure or old age. "The cells of the old mice were indistinguishable from the young mice, after just one week of treatment," said lead author Professor David Sinclair of UNSW School of Medical Sciences and Harvard Medical School Boston.Human trials of NMN therapy will begin within six months."This is the closest we are to a safe and effective anti-ageing drug that's perhaps only three to five years away from being on the market if the trials go well," says Sinclair, who maintains a lab at UNSW in Sydney.

NAD+ IN SOME STUDIES SHOW INCREASED INFLAMMATION

9 May 2019 Boosting Levels of NAD+ May Make Senescent Cells More Aggressively Inflammatory

"...Enhancing levels of NAD+ in mitochondria via delivery of various precursor compounds as supplements is growing in popularity as an approach to boost faltering mitochondrial function and thus modestly slow the progression of aging. A human trial demonstrated improved vascular function as a result of nicotinamide riboside supplementation, for example. Researchers here show that increased NAD+ will likely make worse the inflammatory signaling of senescent cells, however. Senescent cells accumulate with age, and are an important cause of the chronic inflammation of aging that drives the progression of many age-related diseases..." see full article

Abstracts:

24 March 2017 A conserved NAD+ binding pocket that regulates protein-protein interactions during aging

"...NAD+ binding modulates protein interactions An unexpected function of the oxidized form of nicotinamide adenine dinucleotide (NAD+) could underlie some effects of aging and propensity to age-related diseases. Li et al. found that the protein DBC1 (deleted in breast cancer 1) contains a domain that specifically binds NAD+. Binding of NAD+ inhibited the interaction of DBC1 with PARP1 [poly(adenosine diphosphate–ribose) polymerase 1], an enzyme important in DNA repair. Activity of PARP1 is inhibited by interaction with DBC1. Thus, the reduced abundance of NAD+ associated with aging may decrease PARP1 activity by promoting the interaction of PARP1 with DBC1. This mechanism could help explain the reported rejuvenating actions of NAD+ supplementation in older animals...

...Abstract DNA repair is essential for life, yet its efficiency declines with age for reasons that are unclear. Numerous proteins possess Nudix homology domains (NHDs) that have no known function. We show that NHDs are NAD+ (oxidized form of nicotinamide adenine dinucleotide) binding domains that regulate protein-protein interactions. The binding of NAD+ to the NHD domain of DBC1 (deleted in breast cancer 1) prevents it from inhibiting PARP1 [poly(adenosine diphosphate–ribose) polymerase], a critical DNA repair protein. As mice age and NAD+ concentrations decline, DBC1 is increasingly bound to PARP1, causing DNA damage to accumulate, a process rapidly reversed by restoring the abundance of NAD+. Thus, NAD+ directly regulates protein-protein interactions, the modulation of which may protect against cancer, radiation, and aging..." see full publication

18 February 2019 NAD+ metabolism governs the proinflammatory senescence-associated secretome

Cellular senescence is a stable growth arrest that is implicated in tissue ageing and cancer. Senescent cells are characterized by an upregulation of proinflammatory cytokines, which is termed the senescence-associated secretory phenotype (SASP). NAD+ metabolism influences both tissue ageing and cancer. However, the role of NAD+ metabolism in regulating the SASP is poorly understood. Here, we show that nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the NAD+ salvage pathway, governs the proinflammatory SASP independent of senescence-associated growth arrest. NAMPT expression is regulated by high mobility group A (HMGA) proteins during senescence. The HMGA–NAMPT–NAD+ signalling axis promotes the proinflammatory SASP by enhancing glycolysis and mitochondrial respiration. HMGA proteins and NAMPT promote the proinflammatory SASP through NAD+-mediated suppression of AMPK kinase, which suppresses the p53-mediated inhibition of p38 MAPK to enhance NF-κB activity. We conclude that NAD+ metabolism governs the proinflammatory SASP. Given the tumour-promoting effects of the proinflammatory SASP, our results suggest that anti-ageing dietary NAD+ augmentation should be administered with precision. see Nature abstract

6 March 2018 Therapeutic potential of NAD-boosting molecules: the in vivo evidence

Summary: Nicotinamide adenine dinucleotide (NAD), the cell's hydrogen carrier for redox enzymes, is well known for its role in redox reactions. More recently, it has emerged as a signaling molecule. By modulating NAD+ sensing enzymes, it controls hundreds of key processes from energy metabolism to cell survival, rising and falling depending on food intake, exercise and the time of day. NAD+ levels steadily decline with age, resulting in altered metabolism and increased disease susceptibility. Restoration of NAD+ levels in old or diseased animals can promote health and extend lifespan, prompting a search for safe and efficacious NAD-boosting molecules. Such molecules hold the promise of increasing the body's resilience, not just to one disease, but to many, thereby extending healthy human lifespan. Keywords: aging, epigenetics, sirtuins, chromatin, epigenetics, PARP1, cancer, cardiovascular disease, inflammation, nicotinamide riboside, nicotinamide mononucleotide, CD38, STAC. See full publication

April 2019 The Plasma NAD+ Metabolome Is Dysregulated in "Normal" Aging.

Nicotinamide adenine dinucleotide (NAD+) is an essential pyridine nucleotide that serves as an electron carrier in cellular metabolism and plays a crucial role in the maintenance of balanced redox homeostasis. Quantification of NAD+:NADH and NADP+:NADPH ratios are pivotal to a wide variety of cellular processes, including intracellular secondary messenger signaling by CD38 glycohydrolases, DNA repair by poly(adenosine diphosphate ribose) polymerase (PARP), epigenetic regulation of gene expression by NAD-dependent histone deacetylase enzymes known as sirtuins, and regulation of the oxidative pentose phosphate pathway. We quantified changes in the NAD+ metabolome in plasma samples collected from consenting healthy human subjects across a wide age range (20-87 years) using liquid chromatography coupled to tandem mass spectrometry. Our data show a significant decline in the plasma levels of NAD+, NADP+, and other important metabolites such as nicotinic acid adenine dinucleotide (NAAD) with age. However, an age-related increase in the reduced form of NAD+ and NADP+-NADH and NADPH-and nicotinamide (NAM), N-methyl-nicotinamide (MeNAM), and the products of adenosine diphosphoribosylation, including adenosine diphosphate ribose (ADPR) was also reported. Whereas, plasma levels of nicotinic acid (NA), nicotinamide mononucleotide (NMN), and nicotinic acid mononucleotide (NAMN) showed no statistically significant changes across age groups. Taken together, our data cumulatively suggest that age-related impairments are associated with corresponding alterations in the extracellular plasma NAD+ metabolome. Our future research will seek to elucidate the role of modulating NAD+ metabolites in the treatment and prevention of age-related diseases. source and images from publication