scholarly journals NAD Metabolome Analysis in Human Cells Using 1H NMR Spectroscopy

2018 ◽  
Vol 19 (12) ◽  
pp. 3906 ◽  
Author(s):  
Konstantin Shabalin ◽  
Kirill Nerinovski ◽  
Alexander Yakimov ◽  
Veronika Kulikova ◽  
Maria Svetlova ◽  
...  

Nicotinamide adenine dinucleotide (NAD) and its phosphorylated form, NADP, are the major coenzymes of redox reactions in central metabolic pathways. Nicotinamide adenine dinucleotide is also used to generate second messengers, such as cyclic ADP-ribose, and serves as substrate for protein modifications including ADP-ribosylation and protein deacetylation by sirtuins. The regulation of these metabolic and signaling processes depends on NAD availability. Generally, human cells accomplish their NAD supply through biosynthesis using different forms of vitamin B3: Nicotinamide (Nam) and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR). These precursors are converted to the corresponding mononucleotides NMN and NAMN, which are adenylylated to the dinucleotides NAD and NAAD, respectively. Here, we have developed an NMR-based experimental approach to detect and quantify NAD(P) and its biosynthetic intermediates in human cell extracts. Using this method, we have determined NAD, NADP, NMN and Nam pools in HEK293 cells cultivated in standard culture medium containing Nam as the only NAD precursor. When cells were grown in the additional presence of both NAR and NR, intracellular pools of deamidated NAD intermediates (NAR, NAMN and NAAD) were also detectable. We have also tested this method to quantify NAD+ in human platelets and erythrocytes. Our results demonstrate that 1H NMR spectroscopy provides a powerful method for the assessment of the cellular NAD metabolome.

2018 ◽  
Vol 22 (2) ◽  
pp. 235-239
Author(s):  
O. B. Shevelev ◽  
M. P. Moshkin

Deviations in brain metabolism are the result of longterm pathological processes, which finally are manifested as symptoms of Parkinson’s or Alzheimer’s diseases or multiple sclerosis and other neuropathologies, as for example diabetic neuropathy. A deficiency of available energy for brain cells under neurodegenerative diseases is either developed due to age-dependent underexpression of genes that encode glycolytic enzymes or induced due to the uncoupling of oxidation and phosphorylation that could be mediated by inflammatory cytokines. Since the activity of many enzymes is under the control of adenosine triphosphate (ATP) or cofactors, such as nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH), energy deficiency can cause metabolic changes in brain tissue. Some clinical studies using proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) revealed metabolic changes in brain tissue in patients with neurodegenerative diseases. However, data from different authors are quite contradictory, probably because of the complex genesis of metabolic disorders. In the present study, we tested the hypothesis of multidirectional changes in metabolism under the impact of the oxidation and phosphorylation uncoupler 2,4-dinitrophenol (2,4-DNP) and under the impact of 2-deoxy-Dglucose (2-DG), blocking the access of glucose to the brain cells. 1H NMR spectroscopy showed that 2-DG leads to the predominance of excitatory (glutamine + glutamate) neurotransmitters over inhibitory ones (gamma-aminobutyric acid), and 2,4 DNP causes opposite effects. The biochemical mechanisms of the observed changes require a special study, but it can be noted that the ATP deficiency caused by inhibition of glycolysis and the ATP deficiency caused by the uncouplers are accompanied by differently directed changes in the intensity of the tricarboxylic acid cycle. These changes in the intensity of the Krebs cycle are correlated with differently directed changes in the balance of the exciting and inhibitory neurotransmitters. The obtained results show that 1H NMR spectroscopy can be an effective method of differentiated lifetime assessment of the available energy deficit caused by a general suppression of energy exchange in nerve cells or oxidation and phosphorylation uncoupling.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Maria Maganu ◽  
Filip Chiraleu ◽  
Constantin Draghici ◽  
Gheorghe Mihai

The previous data obtained by 1H-NMR spectroscopy established the existence of an asymmetry of the bond between Pd and p-allylic groups, even in the p-allyl-Pd complexes dimers which are considered usually symmetric dimers. The asymmetry of the bond depends by the substitutes of the allylic group. Other analytical methods were investigated for additional proof of the obtained results. Thus, this paper discusses how this asymmetry would be reflected in the infrared spectra and in the reaction of the complexes with carbon monoxide.


2020 ◽  
Vol 07 ◽  
Author(s):  
Christian Trapp ◽  
Corinna Schuster ◽  
Chris Drewniok ◽  
Dieter Greif ◽  
Martin Hofrichter

Background:: Chiral β-hydroxy esters and α-substituted β-hydroxy esters represent versatile building blocks for pheromones, β-lactam antibiotics and 1,2- or 1,3-aminoalcohols. Objective:: Synthesis of versatile α-substituted β-keto esters and their diastereoselective reduction to the corresponding syn- or anti-α-substituted β-hydroxy esters. Assignment of the relative configuration by NMR-spectroscopy after a CURTIUS rearrangement of α-substituted β-keto esters to 4-substituted 5-methyloxazolidin-2-ones. Method:: Diastereoselective reduction was achieved by using different LEWIS acids (zinc, titanium and cerium) in combination with complex borohydrides as reducing agents. Assignment of the relative configuration was verified by 1H-NMR spectroscopy after CURTIUS-rearrangement of α-substituted β-hydroxy esters to 4-substituted 5-methyloxazolidin-2-ones. Results:: For the syn-selective reduction, titanium tetrachloride (TiCl4) in combination with a pyridine-borane complex (py BH3) led to diastereoselectivities up to 99% dr. High anti-selective reduction was achieved by using cerium trichloride (CeCl3) and steric hindered reducing agents such as lithium triethylborohydride (LiEt3BH). After CURTIUS-rearrangement of each α-substituted β-hydroxy ester to the corresponding 4-substituted 5-methyloxazolidin-2-one, the relative configuration was confirmed by 1H NMR-spectroscopy. Conclusion:: We have expanded the procedure of LEWIS acid-mediated diastereoselective reduction to bulky α-substituents such as the isopropyl group and the electron withdrawing phenyl ring.


1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.


2021 ◽  
Vol 22 (3) ◽  
pp. 1391
Author(s):  
Andrey Kropotov ◽  
Veronika Kulikova ◽  
Kirill Nerinovski ◽  
Alexander Yakimov ◽  
Maria Svetlova ◽  
...  

Nicotinamide riboside (NR), a new form of vitamin B3, is an effective precursor of nicotinamide adenine dinucleotide (NAD+) in human and animal cells. The introduction of NR into the body effectively increases the level of intracellular NAD+ and thereby restores physiological functions that are weakened or lost in experimental models of aging and various pathologies. Despite the active use of NR in applied biomedicine, the mechanism of its transport into mammalian cells is currently not understood. In this study, we used overexpression of proteins in HEK293 cells, and metabolite detection by NMR, to show that extracellular NR can be imported into cells by members of the equilibrative nucleoside transporter (ENT) family ENT1, ENT2, and ENT4. After being imported into cells, NR is readily metabolized resulting in Nam generation. Moreover, the same ENT-dependent mechanism can be used to import the deamidated form of NR, nicotinic acid riboside (NAR). However, NAR uptake into HEK293 cells required the stimulation of its active utilization in the cytosol such as phosphorylation by NR kinase. On the other hand, we did not detect any NR uptake mediated by the concentrative nucleoside transporters (CNT) CNT1, CNT2, or CNT3, while overexpression of CNT3, but not CNT1 or CNT2, moderately stimulated NAR utilization by HEK293 cells.


Author(s):  
Masanori Inagaki ◽  
Risa Iwakuma ◽  
Susumu Kawakami ◽  
Hideaki Otsuka ◽  
Harinantenaina L. Rakotondraibe

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