NAD+ supplementation reduces neuroinflammation and cell senescence in a transgenic mouse model of Alzheimer's disease via cGAS-STING.

Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder. Impaired neuronal bioenergetics and neuroinflammation are thought to play key roles in the progression of AD, but their interplay is not clear. Nicotinamide adenine dinucleotide (NAD+) is an important metabolite in all human cells in which it is pivotal for multiple processes including DNA repair and mitophagy, both of which are impaired in AD neurons. Here, we report that levels of NAD+ are reduced and markers of inflammation increased in the brains of APP/PS1 mutant transgenic mice with beta-amyloid pathology. Treatment of APP/PS1 mutant mice with the NAD+ precursor nicotinamide riboside (NR) for 5 mo increased brain NAD+ levels, reduced expression of proinflammatory cytokines, and decreased activation of microglia and astrocytes. NR treatment also reduced NLRP3 inflammasome expression, DNA damage, apoptosis, and cellular senescence in the AD mouse brains. Activation of cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) are associated with DNA damage and senescence. cGAS-STING elevation was observed in the AD mice and normalized by NR treatment. Cell culture experiments using microglia suggested that the beneficial effects of NR are, in part, through a cGAS-STING-dependent pathway. Levels of ectopic (cytoplasmic) DNA were increased in APP/PS1 mutant mice and human AD fibroblasts and down-regulated by NR. NR treatment induced mitophagy and improved cognitive and synaptic functions in APP/PS1 mutant mice. Our findings suggest a role for NAD+ depletion-mediated activation of cGAS-STING in neuroinflammation and cellular senescence in AD.

Effect of Dietary Coenzyme Q10 Plus NADH Supplementation on Fatigue Perception and Health-Related Quality of Life in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, multisystem, and profoundly debilitating neuroimmune disease, probably of post-viral multifactorial etiology. Unfortunately, no accurate diagnostic or laboratory tests have been established, nor are any universally effective approved drugs currently available for its treatment. This study aimed to examine whether oral coenzyme Q10 and NADH (reduced form of nicotinamide adenine dinucleotide) co-supplementation could improve perceived fatigue, unrefreshing sleep, and health-related quality of life in ME/CFS patients. A 12-week prospective, randomized, double-blind, placebo-controlled trial was conducted in 207 patients with ME/CFS, who were randomly allocated to one of two groups to receive either 200 mg of CoQ10 and 20 mg of NADH (n = 104) or matching placebo (n = 103) once daily. Endpoints were simultaneously evaluated at baseline, and then reassessed at 4- and 8-week treatment visits and four weeks after treatment cessation, using validated patient-reported outcome measures. A significant reduction in cognitive fatigue perception and overall FIS-40 score (p < 0.001 and p = 0.022, respectively) and an improvement in HRQoL (health-related quality of life (SF-36)) (p < 0.05) from baseline were observed within the experimental group over time. Statistically significant differences were also shown for sleep duration at 4 weeks and habitual sleep efficiency at 8 weeks in follow-up visits from baseline within the experimental group (p = 0.018 and p = 0.038, respectively). Overall, these findings support the use of CoQ10 plus NADH supplementation as a potentially safe therapeutic option for reducing perceived cognitive fatigue and improving the health-related quality of life in ME/CFS patients. Future interventions are needed to corroborate these clinical benefits and also explore the underlying pathomechanisms of CoQ10 and NADH administration in ME/CFS.

Potential Therapeutic Benefit of NAD+ Supplementation for Glaucoma and Age-Related Macular Degeneration.

Glaucoma and age-related macular degeneration are leading causes of irreversible blindness worldwide with significant health and societal burdens. To date, no clinical cures are available and treatments target only the manageable symptoms and risk factors (but do not remediate the underlying pathology of the disease). Both diseases are neurodegenerative in their pathology of the retina and as such many of the events that trigger cell dysfunction, degeneration, and eventual loss are due to mitochondrial dysfunction, inflammation, and oxidative stress. Here, we critically review how a decreased bioavailability of nicotinamide adenine dinucleotide (NAD; a crucial metabolite in healthy and disease states) may underpin many of these aberrant mechanisms. We propose how exogenous sources of NAD may become a therapeutic standard for the treatment of these conditions.

Deletion of Topoisomerase 1 in excitatory neurons causes genomic instability and early onset neurodegeneration.

Topoisomerase 1 (TOP1) relieves torsional stress in DNA during transcription and facilitates the expression of long (>100 kb) genes, many of which are important for neuronal functions. To evaluate how loss of Top1 affected neurons in vivo, we conditionally deleted (cKO) Top1 in postmitotic excitatory neurons in the mouse cerebral cortex and hippocampus. Top1 cKO neurons develop properly, but then show biased transcriptional downregulation of long genes, signs of DNA damage, neuroinflammation, increased poly(ADP-ribose) polymerase-1 (PARP1) activity, single-cell somatic mutations, and ultimately degeneration. Supplementation of nicotinamide adenine dinucleotide (NAD+) with nicotinamide riboside partially blocked neurodegeneration, and increased the lifespan of Top1 cKO mice by 30%. A reduction of p53 also partially rescued cortical neuron loss. While neurodegeneration was partially rescued, behavioral decline was not prevented. These data indicate that reducing neuronal loss is not sufficient to limit behavioral decline when TOP1 function is disrupted.

NAD+ in sulfur mustard toxicity.

Sulfur mustard (SM) is a toxicant and chemical warfare agent with strong vesicant properties. The mechanisms behind SM-induced toxicity are not fully understood and no antidote or effective therapy against SM exists. Both, the risk of SM release in asymmetric conflicts or terrorist attacks and the usage of SM-derived nitrogen mustards as cancer chemotherapeutics, render the mechanisms of mustard-induced toxicity a highly relevant research subject. Herein, we review a central role of the abundant cellular molecule nicotinamide adenine dinucleotide (NAD+) in molecular mechanisms underlying SM toxicity. We also discuss the potential beneficial effects of NAD+ precursors in counteracting SM-induced damage.

Exogenous nicotinamide adenine dinucleotide regulates energy metabolism via hypothalamic connexin 43.

BACKGROUND: Nicotinamide adenine dinucleotide (NAD)-dependent deacetylase SIRT1 is an important regulator of hypothalamic neuronal function. Thus, an adequate hypothalamic NAD content is critical for maintaining normal energy homeostasis. METHODS: We investigated whether NAD supplementation increases hypothalamic NAD levels and affects energy metabolism in mice. Furthermore, we investigated the mechanisms underlying the effects of exogenous NAD on central metabolism upon entering the hypothalamus. RESULTS: Central and peripheral NAD administration suppressed fasting-induced hyperphagia and weight gain in mice. Extracellular NAD was imported into N1 hypothalamic neuronal cells in a connexin 43-dependent and CD73-independent manner. Consistent with the in vitro data, inhibition of hypothalamic connexin 43 blocked hypothalamic NAD uptake and NAD-induced anorexia. Exogenous NAD suppressed NPY and AgRP transcriptional activity, which was mediated by SIRT1 and FOXO1. CONCLUSIONS: Exogenous NAD is effectively transported to the hypothalamus via a connexin 43-dependent mechanism and increases hypothalamic NAD content. Therefore, NAD supplementation is a potential therapeutic method for metabolic disorders characterized by hypothalamic NAD depletion.

Dietary and nutrition interventions for the therapeutic treatment of chronic fatigue syndrome/myalgic encephalomyelitis: a systematic review.

BACKGROUND: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is characterised by unexplained fatigue for at least 6 months accompanied by a diverse but consistent set of symptoms. Diet modification and nutritional supplements could be used to improve patient outcomes, such fatigue and quality of life. We reviewed and discussed the evidence for nutritional interventions that may assist in alleviating symptoms of CFS/ME. METHODS: Medline, Cinahl and Scopus were systematically searched from 1994 to May 2016. All studies on nutrition intervention were included where CFS/ME patients modified their diet or supplemented their habitual diet on patient-centred outcomes (fatigue, quality of life, physical activity and/or psychological wellbeing). RESULTS: Seventeen studies were included that meet the inclusion criteria. Of these, 14 different interventions were investigated on study outcomes. Many studies did not show therapeutic benefit on CFS/ME. Improvements in fatigue were observed for nicotinamide adenine dinucleotide hydride (NADH), probiotics, high cocoa polyphenol rich chocolate, and a combination of NADH and coenzyme Q10. CONCLUSIONS: This review identified insufficient evidence for the use of nutritional supplements and elimination or modified diets to relieve CFS/ME symptoms. Studies were limited by the number of studies investigating the interventions, small sample sizes, study duration, variety of instruments used, and studies not reporting dietary intake method. Further research is warranted in homogeneous CFS/ME populations.

Effect of coenzyme Q10 plus nicotinamide adenine dinucleotide supplementation on maximum heart rate after exercise testing in chronic fatigue syndrome - A randomized, controlled, double-blind trial.

BACKGROUND & AIMS: Chronic Fatigue Syndrome (CFS) is a complex condition, characterized by severe disabling fatigue with no known cause, no established diagnostic tests, and no universally effective treatment. Several studies have proposed symptomatic treatment with coenzyme Q10 (CoQ10) and nicotinamide adenine dinucleotide (NADH) supplementation. The primary endpoint was to assess the effect of CoQ10 plus NADH supplementation on age-predicted maximum heart rate (max HR) during a cycle ergometer test. Secondary measures included fatigue, pain and sleep. METHODS: A proof-of-concept, 8-week, randomized, controlled, double-blind trial was conducted in 80 CFS patients assigned to receive either CoQ10 plus NADH supplementation or matching placebo twice daily. Maximum HR was evaluated at baseline and at end of the run-in period using an exercise test. Fatigue, pain and sleep were evaluated at baseline, and then reassessed at 4- and 8-weeks through self-reported questionnaires. RESULTS: The CoQ10 plus NADH group showed a significant reduction in max HR during a cycle ergometer test at week 8 versus baseline (P = 0.022). Perception of fatigue also showed a decrease through all follow-up visits in active group versus placebo (P = 0.03). However, pain and sleep did not improve in the active group. Coenzyme Q10 plus NADH was generally safe and well tolerated. CONCLUSIONS: Our results suggest that CoQ10 plus NADH supplementation for 8 weeks is safe and potentially effective in reducing max HR during a cycle ergometer test and also on fatigue in CFS. Further additional larger controlled trials are needed to confirm these findings. Clinical trial registrationThis trial was registered at clinicaltrials.gov as NCT02063126.

Does oral coenzyme Q10 plus NADH supplementation improve fatigue and biochemical parameters in chronic fatigue syndrome?

Chronic fatigue syndrome (CFS) is a chronic and extremely debilitating illness characterized by prolonged fatigue and multiple symptoms with unknown cause, diagnostic test, or universally effective treatment. Inflammation, oxidative stress, mitochondrial dysfunction, and CoQ10 deficiency have been well documented in CFS. We conducted an 8-week, randomized, double-blind placebo-controlled trial to evaluate the benefits of oral CoQ10 (200 mg/day) plus NADH (20 mg/day) supplementation on fatigue and biochemical parameters in 73 Spanish CFS patients. This study was registered in ClinicalTrials.gov (NCT02063126). A significant improvement of fatigue showing a reduction in fatigue impact scale total score (p<0.05) was reported in treated group versus placebo. In addition, a recovery of the biochemical parameters was also reported. NAD+/NADH (p<0.001), CoQ10 (p<0.05), ATP (p<0.05), and citrate synthase (p<0.05) were significantly higher, and lipoperoxides (p<0.05) were significantly lower in blood mononuclear cells of the treated group. These observations lead to the hypothesis that the oral CoQ10 plus NADH supplementation could confer potential therapeutic benefits on fatigue and biochemical parameters in CFS. Larger sample trials are warranted to confirm these findings.

High sensitivity of intestinal CD8+ T cells to nucleotides indicates P2X7 as a regulator for intestinal T cell responses.

The purinoreceptor P2X7 is expressed on subsets of T cells and mediates responses of these cells to extracellular nucleotides such as ATP or NAD(+). We identified P2X7 as a molecule highly up-regulated on conventional CD8alphabeta(+) and unconventional CD8alphaalpha(+) T cells of the intestinal epithelium of mice. In contrast, CD8(+) T cells derived from spleen, mesenteric lymph nodes, and liver expressed only marginal levels of P2X7. However, P2X7 was highly up-regulated on CD8(+) T cells from spleen and lymph nodes when T cells were activated in the presence of retinoic acid. High P2X7 expression on intestinal CD8(+) T cells as well as on CD8(+) T cells incubated with retinoic acid resulted in enhanced sensitivity of cells to extracellular nucleotides. Both cell populations showed a high level of apoptosis following incubation with NAD(+) and the ATP derivative 2',3'-O-(benzoyl-4-benzoyl)-ATP, and injection of NAD(+) caused selective in vivo depletion of intestinal CD8(+) T cells. Following oral infection with Listeria monocytogenes, P2X7-deficient mice showed similar CD8(+) T cell responses in the spleen, but enhanced responses in the intestinal mucosa, when compared with similarly treated wild-type control mice. Overall, our observations define P2X7 as a new regulatory element in the control of CD8(+) T cell responses in the intestinal mucosa.

Comparison of metabolic fates of nicotinamide, NAD+ and NADH administered orally and intraperitoneally; characterization of oral NADH.

Since NADH has been implicated in medication for some symptoms and as a possible supplement for health, we characterized the metabolic fate of NADH orally given to mice by comparing with those of nicotinamide (Nam), NAD+ and NADH intraperitoneally or orally administered. Mice were individually housed in metabolic cages, and divided into two sets of four groups. Within each set, one group was intraperitoneally or orally administered saline and the other three groups received intraperitoneal or oral administration of a pharmacological dose of Nam, NAD+ or NADH (5 micromol/mouse). Twenty-four hour urine samples for the day before and days 1 to 4 after administration were collected and analyzed for Nam and its metabolites. When mice were administered saline alone, urinary excretion of Nam and its metabolites, such as nicotinamide N-oxide (Nam N-oxide), N1-methylnicotinamide (MNA), N1-methyl-2-pyridone-5-carboxamide (2-Py), and N1-methyl-4-pyridone-3-carboxamide (4-Py), was unchanged from day 0 to day 4. Intraperitoneal injection of Nam, NAD+ and NADH produced significant increases in urinary excretion of Nam and its metabolites. Similar results were obtained when Nam and NAD+ were given orally. On the other hand, oral administration of NADH did not bring about an increase in urinary excretion of Nam and its metabolites, suggesting that NADH in digestive organs has been decomposed to a compound(s) that cannot yield Nam. In fact, incubation of NADH at acidic pH to mimic the stomach resulted in rapid conversion of NADH to an unknown compound. Better understanding of the fate of oral NADH is needed for its therapeutic and supplemental use.

[Stabilized NADH (ENADA) improves jet lag-induced cognitive performance deficit]. / Stabilisiertes NADH (ENADA) verbessert die durch Jetlag reduzierte Hirnleistung.

Current remedies for jet lag (phototherapy, melatonin, stimulant, and sedative medications) are limited in efficacy and practicality. The efficacy of a stabilized, sublingual form of reduced nicotinamide adenine dinucleotide (NADH, ENADAlert, Menuco Corp.) as a countermeasure for jet lag was examined. Because NADH increases cellular production of ATP and facilitates dopamine synthesis, it may counteract the effects of jet lag on cognitive functioning and sleepiness. Thirty-five healthy, employed subjects participated in this double-blind, placebo-controlled study. Training and baseline testing were conducted on the West Coast before subjects flew overnight to the East Coast, where they would experience a 3-hour time difference. Upon arrival, individuals were randomly assigned to received either 20 mg of sublingual stabilized NADH (n = 18) or identical placebo tablets (n = 17). All participants completed computer-administered tests (including Cog Screen) to assess changes in cognitive functioning, mood, and sleepiness in the morning and afternoon. Jet lag resulted in increased sleepiness for over half the participants and deterioration of cognitive functioning for approximately one third. The morning following the flight, subjects experienced lapses of attention in addition to disruptions in working memory, divided attention, and visual perceptual speed. Individuals who received NADH performed significantly better on 4 cognitive test measures (P < or = .05) and reported less sleepiness compared with those who received placebo. No adverse effects were observed with NADH treatment. Stabilized NADH significantly reduced jet lag-induced negative cognitive effects and sleepiness, was easily administered, and was found to have no side effects.

Deoxypodophyllotoxin 6-hydroxylase, a cytochrome P450 monooxygenase from cell cultures of Linum flavum involved in the biosynthesis of cytotoxic lignans.

Cell-suspension cultures of Linum flavum L. (Linaceae) synthesize and accumulate aryltetrahydronaphthalene lignans with 6-methoxypodophyllotoxin as the main component. The experimental data indicate that the biosynthesis of 6-methoxypodophyllotoxin occurs via deoxypodophyllotoxin, beta-peltatin, and beta-peltatin-A methyl ether. The enzyme catalyzing the introduction of the hydroxyl group in position 6 is deoxypodophyllotoxin 6-hydroxylase (DOP6H). The enzyme was shown to be a cytochrome P450-dependent monooxygenase by blue-light reversion of carbon monoxide inhibition and inhibition by cytochrome c. DOP6H is a membrane-bound microsomal enzyme with a pH optimum of 7.6 and a temperature optimum of 26 degrees C. Deoxypodophyllotoxin is specifically accepted with an apparent Km of 20 microM and a saturation concentration of 200 microM; 4'-demethyldeoxypodophyllotoxin is the only other tested substrate accepted for hydroxylation. DOP6H predominantly accepts NADPH as electron donor; NADH can only sustain low hydroxylation activities. A synergistic effect of NADPH and NADH is not observed. The enzyme is saturated around 250 microM NADPH; the apparent Km for this substrate is 36 microM.

Quantitative efficacy of niacin sources for chicks: nicotinic acid, nicotinamide, NAD and tryptophan.

A niacin-deficient diet based upon corn and casein was used to establish growth-promoting efficacy of various sources of niacin activity. In the presence of excess dietary nicotinamide, chicks fed the corn-casein diet achieved maximal weight gain when 100 mg/kg of L-tryptophan was supplemented. The basal diet for efficacy studies therefore contained 100 mg/kg of added tryptophan and no supplemental nicotinic acid. Weight gain in the linear response surface of the growth curve proved to be a far better measure of niacin bioactivity than tissue accumulation of NAD(P). Slope-ratio growth efficacy studies indicated that excess dietary tryptophan was 1.94 +/- 0.14% as efficient as nicotinic acid in furnishing bioavailable niacin activity (52:1, wt:wt). Relative to nicotinic acid used as a standard (100%), nicotinamide bioactivity was 124%. Nicotinamide in NAD was utilized with an efficiency of 95% relative to nicotinamide per se.