scholarly journals Nicotinamide Phosphoribosyltransferase as a Key Molecule of the Aging/Senescence Process

2021 ◽  
Vol 22 (7) ◽  
pp. 3709
Author(s):  
Fiqri D. Khaidizar ◽  
Yasumasa Bessho ◽  
Yasukazu Nakahata

Aging is a phenomenon underlined by complex molecular and biochemical changes that occur over time. One of the metabolites that is gaining strong research interest is nicotinamide adenine dinucleotide, NAD+, whose cellular level has been shown to decrease with age in various tissues of model animals and humans. Administration of NAD+ precursors, nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), to supplement NAD+ production through the NAD+ salvage pathway has been demonstrated to slow down aging processes in mice. Therefore, NAD+ is a critical metabolite now understood to mitigate age-related tissue function decline and prevent age-related diseases in aging animals. In human clinical trials, administration of NAD+ precursors to the elderly is being used to address systemic age-associated physiological decline. Among NAD+ biosynthesis pathways in mammals, the NAD+ salvage pathway is the dominant pathway in most of tissues, and NAMPT is the rate limiting enzyme of this pathway. However, only a few activators of NAMPT, which are supposed to increase NAD+, have been developed so far. In this review, we will focus on the importance of NAD+ and the possible application of an activator of NAMPT to promote successive aging.

Biomolecules ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Saikat Kumar Poddar ◽  
Ali Ehsan Sifat ◽  
Sanjana Haque ◽  
Noor Ahmed Nahid ◽  
Sabiha Chowdhury ◽  
...  

Nicotinamide mononucleotide (NMN) is a nucleotide that is most recognized for its role as an intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis. Although the biosynthetic pathway of NMN varies between eukaryote and prokaryote, two pathways are mainly followed in case of eukaryotic human—one is through the salvage pathway using nicotinamide while the other follows phosphorylation of nicotinamide riboside. Due to the unavailability of a suitable transporter, NMN enters inside the mammalian cell in the form of nicotinamide riboside followed by its subsequent conversion to NMN and NAD+. This particular molecule has demonstrated several beneficial pharmacological activities in preclinical studies, which suggest its potential therapeutic use. Mostly mediated by its involvement in NAD+ biosynthesis, the pharmacological activities of NMN include its role in cellular biochemical functions, cardioprotection, diabetes, Alzheimer's disease, and complications associated with obesity. The recent groundbreaking discovery of anti-ageing activities of this chemical moiety has added a valuable essence in the research involving this molecule. This review focuses on the biosynthesis of NMN in mammalian and prokaryotic cells and mechanism of absorption along with the reported pharmacological activities in murine model.


2020 ◽  
Vol 21 (13) ◽  
pp. 4655
Author(s):  
Duo Feng ◽  
DongZhu Xu ◽  
Nobuyuki Murakoshi ◽  
Kazuko Tajiri ◽  
Rujie Qin ◽  
...  

Aging and obesity are the most prominent risk factors for onset of atrial fibrillation (AF). Nicotinamide phosphoribosyltransferase (Nampt) is the rate-limiting enzyme that catalyzes nicotinamide adenine dinucleotide (NAD) activity. Nampt and NAD are essential for maintenance of cellular redox homeostasis and modulation of cellular metabolism, and their expression levels decrease with aging and obesity. However, a role for Nampt in AF is unknown. The present study aims to test whether there is a role of Nampt/NAD axis in the pathogenesis of obesity-induced AF. Male C57BL/6J (WT) mice and heterozygous Nampt knockout (NKO) mice were fed with a normal chow diet (ND) or a high-fat diet (HFD). Electrophysiological study showed that AF inducibility was significantly increased in WT+HFD, NKO+ND, and NKO+HFD mice compared with WT+ND mice. AF duration was significantly longer in WT+HFD and NKO+ND mice and further prolonged in NKO+HFD mice compared with WT+ND mice and the calcium handling pathway was altered on molecular level. Also, treatment with nicotinamide riboside, a NAD precursor, partially restored the HFD-induced AF perpetuation. Overall, this work demonstrates that partially deletion of Nampt facilitated HFD-induced AF through increased diastolic calcium leaks. The Nampt/NAD axis may be a potent therapeutic target for AF.


2021 ◽  
pp. ASN.2020081188
Author(s):  
Itaru Yasuda ◽  
Kazuhiro Hasegawa ◽  
Yusuke Sakamaki ◽  
Hirokazu Muraoka ◽  
Takahisa Kawaguchi ◽  
...  

BackgroundThe activation of NAD+-dependent deacetylase, Sirt1, by the administration of nicotinamide mononucleotide (NMN) ameliorates various aging-related diseases.MethodsDiabetic db/db mice were treated with NMN transiently for 2 weeks and observed for effects on diabetic nephropathy (DN).ResultsAt 14 weeks after the treatment period, NMN attenuated the increases in urinary albumin excretion in db/db mice without ameliorating hemoglobin A1c levels. Short-term NMN treatment mitigated mesangium expansion and foot process effacement, while ameliorating decreased Sirt1 expression and increased claudin-1 expression in the kidneys of db/db mice. This treatment also improved the decrease in the expression of H3K9me2 and DNMT1. Short-term NMN treatment also increased kidney concentrations of NAD+ and the expression of Sirt1 and nicotinamide phosphoribosyltransferase (Nampt), and it maintained nicotinamide mononucleotide adenyltransferase1 (Nmnat1) expression in the kidneys. In addition, survival rates improved after NMN treatment.Conclusions:Short-term NMN treatment in early-stage DN has remote renal protective effects through the upregulation of Sirt1 and activation of the NAD+ salvage pathway, both of which indicate NMN legacy effects on DN.


2020 ◽  
Vol 21 (22) ◽  
pp. 8840
Author(s):  
Janusz Blasiak ◽  
Elzbieta Pawlowska ◽  
Anna Sobczuk ◽  
Joanna Szczepanska ◽  
Kai Kaarniranta

Aging induces several stress response pathways to counterbalance detrimental changes associated with this process. These pathways include nutrient signaling, proteostasis, mitochondrial quality control and DNA damage response. At the cellular level, these pathways are controlled by evolutionarily conserved signaling molecules, such as 5’AMP-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), insulin/insulin-like growth factor 1 (IGF-1) and sirtuins, including SIRT1. Peroxisome proliferation-activated receptor coactivator 1 alpha (PGC-1α), encoded by the PPARGC1A gene, playing an important role in antioxidant defense and mitochondrial biogenesis, may interact with these molecules influencing lifespan and general fitness. Perturbation in the aging stress response may lead to aging-related disorders, including age-related macular degeneration (AMD), the main reason for vision loss in the elderly. This is supported by studies showing an important role of disturbances in mitochondrial metabolism, DDR and autophagy in AMD pathogenesis. In addition, disturbed expression of PGC-1α was shown to associate with AMD. Therefore, the aging stress response may be critical for AMD pathogenesis, and further studies are needed to precisely determine mechanisms underlying its role in AMD. These studies can include research on retinal cells produced from pluripotent stem cells obtained from AMD donors with the mutations, either native or engineered, in the critical genes for the aging stress response, including AMPK, IGF1, MTOR, SIRT1 and PPARGC1A.


1970 ◽  
Vol 48 (12) ◽  
pp. 2267-2278 ◽  
Author(s):  
H. R. Godavari ◽  
E. R. Waygood

Leaves of wheat (Triticum aestivum L. var. Selkirk) were incubated with nicotinic acid-7-14C and nicotinamide-7-14C for varying time periods from 5 min to 12 h. Aliquots of alcoholic extracts of leaves were subjected to paper chromatography and radioautography to isolate the intermediates of the synthesis and breakdown of nicotinamide adenine dinucleotide. Nine compounds were isolated quantitatively and identified as intermediates in the pathway of NAD metabolism. All the intermediates were labeled rapidly and the rapidity of labeling became a problem in rigorously proving the sequential operation of the pathway. The results indicate that the Preiss-Handler pathway: nicotinic acid→nicotinic acid mononucleotide→nicotinic acid adenine dinucleotide→NAD operates in wheat leaves. The degradation of NAD proceeded from NAD→nicotinamide mononucleotide→nicotinamide riboside→nicotinamide. Deamidation of the nicotinamide to nicotinic acid initiated a fresh cycle of biosynthesis. The total radioactivity recovered in the intermediates indicates that no measurable amount was lost to other metabolic pathways. Nicotinamide is recovered without significant loss and recycled. The rapid appearance of labeled nicotinamide indicates a possible interconversion of nicotinic acid and nicotinamide. About 80% of the radioactivity accumulated was present in trigonelline which is considered, on the basis of other evidence, to be a non-toxic form of nicotinic acid. Benzimidazole treatment of the leaves increased the incorporation of 14C into NADP.


2007 ◽  
Vol 9 (3) ◽  
pp. 1-17 ◽  
Author(s):  
Rania D. Kovaiou ◽  
Dietmar Herndler-Brandstetter ◽  
Beatrix Grubeck-Loebenstein

Average life expectancy is continuously rising in all developed countries, leading to an ever-increasing elderly population. Of the many functions of the body affected by the complex process of ageing, the immune system in particular undergoes various changes, collectively termed immunosenescence. As a result, elderly people are more susceptible to infections and are frequently less protected by vaccines. This review summarises the effect of ageing on immunity, emphasising the age-associated changes within T and B cells at a molecular and cellular level. Furthermore, it discusses strategies, such as the addition of immunostimulatory adjuvants and the use of potent antigen-delivery systems, that may counteract age-related defects in immune responses to vaccination. A proper understanding of how immunological memory is affected by ageing, and the introduction of strategies to ameliorate vaccine efficacy in the elderly, might reduce the incidence and the severity of infectious disease within this fragile age group and have a strong impact on the quality of life of elderly individuals.


2021 ◽  
pp. 0271678X2110062
Author(s):  
Min Zeng ◽  
Tao-Feng Wei ◽  
Cong Chen ◽  
Chen Shen ◽  
Tong-Yao Gao ◽  
...  

Nicotinamide phosphoribosyltransferase (NAMPT) is the key enzyme for the synthesis of nicotinamide adenine dinucleotide (NAD) in the salvaging pathway. Though NAMPT inhibitors such as FK866 were originally developed as anti-cancer drugs, they also display neuroprotective effects. Here we show that the administration of FK866 at 0.5 mg/kg (ip, qod) for four weeks, i.e., ∼1% of the dose used for the treatment of cancer, significantly alleviates the aging-induced impairment of cognition and locomotor activity. Mechanistically, FK866 enhanced autophagy, reduced protein aggregation, and inhibited neuroinflammation indicated by decreasing TNFα, IL-6, GFAP, and Iba1 levels in the aged mouse brain. Though FK866 did not affect the total NAD and nicotinamide mononucleotide (NMN) levels in the mouse brain at the dose we used, FK866 increased nicotinamide (NAM) level in the young mouse brain and decreased NAM level in the aged mouse brain. On the other hand, FK866 did not affect the serum glucose, cholesterol, and triglyceride of young and aged mice and exhibited no effects on the various indices of young mice. Thus, the NAMPT inhibitor can be repurpose to counteract the cognitive impairment upon aging. We also envision that NAMPT inhibitor can be used for the treatment of age-related neurodegenerative diseases.


2020 ◽  
Vol 5 (3) ◽  
pp. 182-198
Author(s):  
Fatemeh Ghorbania ◽  
◽  
Masoomeh Ghorbani ◽  
Arezou Ghahghaee ◽  

Diabetes is a group of metabolic disorders characterized by a high blood sugar level over a prolonged period of time. Inhibition of carbohydrate hydrolyzing enzymes leads to decrease in the absorption of glucose which is considered as one of the effective managements of diabetes mellitus. Vegetable, fruit, milk and fish are good sources of nucleosides and inosine (INO), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) with versatile health benefits. The well-adapted structural features of these compounds for the inhibition/activation of enzymes include several available hydrogen bond (H-bond) acceptors and donors, flexible backbone and hydrophobic nature. The substrates of α-amylase (α-Amy) and α-Glucosidase (α-Glu), known as key absorbing enzymes, have functional groups (OH groups) resembling nucleosides. Therefore, the present study was conducted to evaluate the inhibitory properties of nucleosides against αAmy and α-Glu. The median inhibition concentration (IC50) values for α-Glu in the presence of adenosine (ADN), adenosine triphosphate (AMP), NR, INO, adenosine triphosphate (ATP), nicotinamide adenine dinucleotide (NAD), Adenosine diphosphate (ADP)-ribose, ADP-glucose and NMN were determined 208.6±3.8, 254.1±5.2, 177.7±4.8, 192.1±5.2, 215.9±2.7, 65.4±1.3, 63.4±2.2, 75.6±4.2 and 196.1±2.6, respectively. The IC50 values α-Amy in the presence of ADN, AMP, NR, INO, ATP, NAD, ADP-ribose, ADP-glucose and NMN were determined 145.3±2.4, 202.3±3.9, 127.7±4.8, 163.5±3.6, 185.3±1.2, 80.4±2.8, 64.8±4.7, 51.1±1.6 and 166.5±1.4, respectively. Moreover, the Ki values of NAD were calculated as 13.8±0.8 and 18.6±2.4 µM for α-Glu and α-Amy in a competitive-mode and noncompetitive -mode inhibition. In addition, to communicate with the active site of α-Glu and α-Amy respectively, NR presented a binding energy of -7.8 and -6.8 kcal/mol, INO -7.3 and -6.9, ATP -8.3 and -7.3, NAD -10.0 and -8.5, ADP-ribose -8.7 and -7.4, ADP-glucose -8.9 and -7.6, cAMP -6.6 and -6.3 and NMN -6.8 and -7.0 kcal/mol. These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index, but also to limit the activity of the major reactive oxygen species (ROS) producing pathways. Key words: Nucleosides, NAD, hydrolyzing enzymes, enzyme inhibition, hyperglycemia


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
William E. Schutzer ◽  
Scott L. Mader

Hypertension, orthostatic hypotension, arterial insufficiency, and atherosclerosis are common disorders in the elderly that lead to significant morbidity and mortality. One common factor to these conditions is an age-related decline in vascular beta-adrenergic receptor-mediated function and subsequent cAMP generation. Presently, there is no single cellular factor that can explain this age-related decline, and thus, the primary cause of this homeostatic imbalance is yet to be identified. However, the etiology is clearly associated with an age-related change in the ability of beta-adrenergic receptor to respond to agonist at the cellular level in the vasculature. This paper will review what is presently understood regarding the molecular and biochemical basis of age-impaired beta-adrenergic receptor-mediated signaling. A fundamental understanding of whyβ-AR-mediated vasorelaxation is impaired with age will provide new insights and innovative strategies for the management of multiple clinical disorders.


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