1
|
Deery DJ, Taylor KW. Effect of phenylpyruvate on enzymes involved in fatty acid synthesis in rat brain. Biochem J 2010; 134:557-63. [PMID: 16742817 PMCID: PMC1177843 DOI: 10.1042/bj1340557] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
1. The effects of azaserine and nicotinamide, agents which inhibit and stimulate hepatic NAD synthesis respectively, on the content of NAD(+) and NADH in isolated rat islets of Langerhans incubated in vitro were studied. The effects of these compounds on the rates of insulin release, from isolated islets incubated in vitro, in response to various secretagogues were also measured. 2. Preincubation of islets in the presence of azaserine (0.3mm) caused a marked depletion of the normal islet-cell content of both NAD(+) and NADH and prevented the secretion of insulin in response to stimulatory concentrations of d-glucose, xylitol, d-xylulose, l-arginine hydrochloride and l-leucine. 3. Preincubation of islets in the presence of nicotinamide (2mm) increased the islet content of NAD(+) and enhanced the rate of release of insulin in response to d-glucose. Also when nicotinamide was present the inhibitory effect of azaserine on insulin release and the azaserine-induced depletion of the islet content of NAD(+) and NADH was prevented. 4. Preincubation with azaserine was without effect on the stimulation of insulin release caused by theophylline or dibutyryl cyclic AMP. 5. It is suggested that insulin release caused by sugars and amino acids is dependent on the maintenance of NAD concentrations, though this may not be the case for release due to theophylline and dibutyryl cyclic AMP.
Collapse
Affiliation(s)
- D J Deery
- Biochemistry Group, School of Biology, University of Sussex, Falmer, Brighton BN1 9QG, U.K
| | | |
Collapse
|
2
|
Said HM, Nabokina SM, Balamurugan K, Mohammed ZM, Urbina C, Kashyap ML. Mechanism of nicotinic acid transport in human liver cells: experiments with HepG2 cells and primary hepatocytes. Am J Physiol Cell Physiol 2007; 293:C1773-8. [PMID: 17928533 DOI: 10.1152/ajpcell.00409.2007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study reports on the functional expression of a specific, high-affinity carrier-mediated mechanism for the transport of niacin (nicotinic acid) in human liver cells. Both human-derived liver HepG2 cells and human primary hepatocytes were used as models in these investigations. The initial rate of transport of nicotinic acid into HepG2 cells was found to be acidic pH, temperature, and energy dependent; it was, however, Na(+) independent in nature. Evidence for the existence of a carrier-mediated system that is specific for [(3)H]nicotinic acid transport was found and included the following: 1) saturability as a function of concentration with an apparent K(m) of 0.73 +/- 0.16 microM and V(max) of 25.02 +/- 1.45 pmol.mg protein(-1).3 min(-1), 2) cis-inhibition by unlabeled nicotinic acid and nicotinamide but not by unrelated organic anions (lactate, acetate, butyrate, succinate, citrate, and valproate), and 3) trans-stimulation of [(3)H]nicotinic acid efflux by unlabeled nicotinic acid. Transport of the vitamin into human primary hepatocytes occurs similarly via an acidic pH-dependent and specific carrier-mediated process. Inhibitors of the Ca(2+)-calmodulin-mediated pathway (but not modulators of the PKC-, PKA-, and protein tyrosine kinase-mediated pathways) inhibited nicotinic acid transport into both HepG2 cells and human primary hepatocytes. Maintenance of HepG2 cells (for 48 h) in growth medium oversupplemented with nicotinic acid (or nicotinamide) did not affect the subsequent transport of [(3)H]nicotinic acid into HepG2 cells. These results show, for the first time, the existence of a specific and regulated membrane carrier-mediated system for nicotinic acid transport in human liver cells.
Collapse
Affiliation(s)
- Hamid M Said
- Veterans Affairs Medical Center, Long Beach, CA 90822, USA.
| | | | | | | | | | | |
Collapse
|
3
|
Hara N, Yamada K, Shibata T, Osago H, Hashimoto T, Tsuchiya M. Elevation of cellular NAD levels by nicotinic acid and involvement of nicotinic acid phosphoribosyltransferase in human cells. J Biol Chem 2007; 282:24574-82. [PMID: 17604275 DOI: 10.1074/jbc.m610357200] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
NAD plays critical roles in various biological processes through the function of SIRT1. Although classical studies in mammals showed that nicotinic acid (NA) is a better precursor than nicotinamide (Nam) in elevating tissue NAD levels, molecular details of NAD synthesis from NA remain largely unknown. We here identified NA phosphoribosyltransferase (NAPRT) in humans and provided direct evidence of tight link between NAPRT and the increase in cellular NAD levels. The enzyme was abundantly expressed in the small intestine, liver, and kidney in mice and mediated [(14)C]NAD synthesis from [(14)C]NA in human cells. In cells expressing endogenous NAPRT, the addition of NA but not Nam almost doubled cellular NAD contents and decreased cytotoxicity by H(2)O(2). Both effects were reversed by knockdown of NAPRT expression. These results indicate that NAPRT is essential for NA to increase cellular NAD levels and, thus, to prevent oxidative stress of the cells. Kinetic analyses revealed that NAPRT, but not Nam phosphoribosyltransferase (NamPRT, also known as pre-B-cell colony-enhancing factor or visfatin), is insensitive to the physiological concentration of NAD. Together, we conclude that NA elevates cellular NAD levels through NAPRT function and, thus, protects the cells against stress, partly due to lack of feedback inhibition of NAPRT but not NamPRT by NAD. The ability of NA to increase cellular NAD contents may account for some of the clinically observed effects of the vitamin and further implies a novel application of the vitamin to treat diseases such as those associated with the depletion of cellular NAD pools.
Collapse
Affiliation(s)
- Nobumasa Hara
- Department of Biochemistry, Shimane University Faculty of Medicine, 89-1, Izumo, Shimane 693-8501, Japan.
| | | | | | | | | | | |
Collapse
|
4
|
Evans J, Wang TC, Heyes MP, Markey SP. LC/MS analysis of NAD biosynthesis using stable isotope pyridine precursors. Anal Biochem 2002; 306:197-203. [PMID: 12123656 DOI: 10.1006/abio.2002.5715] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A liquid chromatographic-electrospray ionization ion trap mass spectrometry (LC/MS) method has been developed to measure the biosynthetic incorporation of specific precursors into NAD. The stable isotope-labeled precursors tryptophan, quinolinic acid, nicotinic acid, and nicotinamide were added to the media of human liver tumor cells (SK-HEP) grown in culture. The cells were harvested, the NAD was extracted, and the ratio of labeled to unlabeled NAD was measured using the newly developed LC/MS assay. The quantity of NAD formed from each precursor relative to an internal standard (fully labeled 13C, 15N-labeled NAD prepared from baker's yeast) was measured. The detection limit (signal-to-noise ratio 5:1) of the LC/MS method was 37 fmol (25 pg) of NAD and was linear from 20.0 ng to 25 pg. All reported NAD levels were normalized relative to cellular protein measurements. At 50 microM precursor concentrations, nicotinamide was the dominant precursor and NAD levels in the cell rose well above normal levels. Other precursors were minimally incorporated. The same methods were applied to NAD biosynthesized by macrophages derived from peripheral blood monocytes. However, the NAD concentration in macrophages was about 5% of that in SK-HEP cells and the incorporation of stable isotope-labeled substrates remained below measurable levels.
Collapse
Affiliation(s)
- Jason Evans
- Laboratory of Neurotoxicology, National Institute of Mental Health, Bethesda, Maryland 20892-1262, USA
| | | | | | | |
Collapse
|
5
|
Ko?odziejska-Huben M, Kami?ski Z, Paneth P. Preparation of18O-labelled nicotinamide. J Labelled Comp Radiopharm 2002. [DOI: 10.1002/jlcr.617] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
6
|
Devin A, Nogueira V, Leverve X, Guérin B, Rigoulet M. Allosteric activation of pyruvate kinase via NAD+ in rat liver cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3943-9. [PMID: 11453987 DOI: 10.1046/j.1432-1327.2001.02306.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In isolated rat hepatocytes, it has previously been reported that a rise in the ATP content induces a proportional increase in cytosolic NAD+ concentration [Devin, A., Guérin, B. & Rigoulet, M. (1997) FEBS Lett. 410, 329-332]. This occurs under physiological conditions such as various substrates or different energetic states. To investigate the effect of a physiological rise in cytosolic [NAD+] per se on glycolysis and gluconeogenesis, an increase in [NAD+] induced by exogenous nicotinamide addition was obtained without a change in redox potential, ATP/ADP ratio and ATP concentration. Using dihydroxyacetone as substrate, we found that an increase in cytosolic [NAD+] decreases gluconeogenesis and enhances glycolysis without significant alteration of dihydroxyacetone consumption rate. These modifications are the consequence of an allosteric activation of pyruvate kinase via cytosolic NAD+ content. Thus, in addition to the well-known thermodynamic control of glycolysis by pyridine-nucleotide redox status, our study points to a new mechanism of glycolytic flux regulation by NAD+ concentration at the level of pyruvate kinase activity.
Collapse
Affiliation(s)
- A Devin
- NIH, NCI, Bldg 10, Room 6 N105, Bethesda, MD 20892, USA
| | | | | | | | | |
Collapse
|
7
|
Bender DA, Olufunwa R. Utilization of tryptophan, nicotinamide and nicotinic acid as precursors for nicotinamide nucleotide synthesis in isolated rat liver cells. Br J Nutr 1988; 59:279-87. [PMID: 2965917 DOI: 10.1079/bjn19880035] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Incubation of isolated rat hepatocytes with nicotinamide or nicotinic acid showed that while both vitamers were taken up from the incubation medium, neither was utilized to any significant extent as a precursor of the nicotinamide nucleotide coenzymes, NAD and NADP, and neither was capable of preventing the loss of nucleotides that occurs on incubating the cells. 2. Incubation of hepatocytes with tryptophan showed that de novo synthesis from tryptophan permitted replacement of the nucleotides lost during incubation; at high concentrations of tryptophan there was an increase above the initial intracellular concentration of NAD(P). Incubation of hepatocytes with tryptophan also resulted in the formation and release from the cells of a considerable amount of niacin, as well as the two principal metabolities of NAD(P), N1-methyl nicotinamide and methyl pyridone carboxamide. 3. It is suggested that, in the liver, performed niacin is not utilized for nucleotide synthesis, and indeed the function of the liver appears to be synthesis of niacin from tryptophan, and its release for use by extrahepatic tissues that lack the pathway for de novo synthesis of nicotinamide nucleotides from tryptophan.
Collapse
Affiliation(s)
- D A Bender
- Department of Biochemistry, University College, London
| | | |
Collapse
|
8
|
Carson DA, Seto S, Wasson DB, Carrera CJ. DNA strand breaks, NAD metabolism, and programmed cell death. Exp Cell Res 1986; 164:273-81. [PMID: 2940104 DOI: 10.1016/0014-4827(86)90028-5] [Citation(s) in RCA: 243] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An intimate relationship exists between DNA single-strand breaks, NAD metabolism, and cell viability in quiescent human lymphocytes. Under steady-state conditions, resting lymphocytes continually break and rejoin DNA. The balanced DNA excision-repair process is accompanied by a proportional consumption of NAD for poly(ADP-ribose) synthesis. However, lymphocytes have a limited capacity to resynthesize NAD from nicotinamide. An increase in DNA strand break formation in lymphocytes, or a block in DNA repair, accelerates poly(ADP-ribose) formation and may induce lethal NAD and ATP depletion. In this way, the level of DNA single-strand breaks in the lymphocyte nucleus is linked to the metabolic activity of the cytoplasm. The programmed removal of lymphocytes (and perhaps of other cells) with damaged DNA, may represent a novel physiologic function for poly(ADP-ribose)-dependent NAD cycling.
Collapse
|
9
|
Paine AJ, Allen CM, Durkacz BW, Shall S. Evidence that poly(ADP-ribose) polymerase is involved in the loss of NAD from cultured rat liver cells. Biochem J 1982; 202:551-3. [PMID: 6284133 PMCID: PMC1158142 DOI: 10.1042/bj2020551] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rat hepatocytes cultured from 24h lose 60% of their NAD content. By using the differential response to inhibitors of the two major enzymes that catabolize NAD in mammalian cells, it is shown that poly(ADP-ribose) polymerase is responsible for the loss of NAD. The relevance of this observation to the use of cultured hepatocytes for the study of DNA repair induced by carcinogens is discussed.
Collapse
|
10
|
Delabar U, Siess M. Synthesis and degradation of NAD in guinea pig cardiac muscle: II. Studies about the different biosynthetic pathways and the corresponding intermediates. Basic Res Cardiol 1979; 74:571-93. [PMID: 44842 DOI: 10.1007/bf01907500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
11
|
Minaga T, Marton LJ, Piper WN, Kun E. Induction of cardiac L-ornithine decarboxylase by nicotinamide and its regulation by putrescine. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 91:577-85. [PMID: 153228 DOI: 10.1111/j.1432-1033.1978.tb12711.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
12
|
Ferro AM, Kuehl L. Adenosine triphosphate: nicotinamide mononucleotide adenylyltransferase of pig liver. Purification and properties. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 410:285-9. [PMID: 1090 DOI: 10.1016/0005-2744(75)90231-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adenosine triphosphate : nicotinamide mononucleotide adenylyltransferase (EC 2.7.7.1) has been purifiec approximately 3500-fold from an extract of pig liver nuclei to a specific activity of 40 mumol of NAD+ per min per mg protein. The enzyme was found to have a molecular weight of 203 000, a frictional ratio of 1.6 and an isoelectric point of approximately 5. Michaelis constants for ATP and NMN were 0.11 mM and 0.12 mM, respectively.
Collapse
|
13
|
Griffith GR, Chandler JL, Gholson RK. Studies on the de novo biosynthesis of NAD in Escherichia coli. The separation of the nadB gene product from the nadA gene product and its purification. EUROPEAN JOURNAL OF BIOCHEMISTRY 1975; 54:239-45. [PMID: 238844 DOI: 10.1111/j.1432-1033.1975.tb04133.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Quinolinic acid (pyridine 2,3-dicarboxylic acid) which is an immediate precursor of the pyridine nucleotides, is synthesised from L-asparate and dihydroxyacetone phosphate in Escherichia coli. Extracts from certain nadB mutants complement the extracts prepared from all nadA mutants for the enzymic synthesis of quinolinate. Using the complementation assay, the quinolinate synthetase B protein has been purified more than 300-fold. The quinolinate synthetase B protein exists in all nadA and nadC mutants examined. The quinolinate synthetase A protein was present in all nadC mutants and most (but not all) nadB mutants. The facile separation of the wild-type quinolinate synthetase A and B proteins out of a nadC mutant suggests that quinolinate synthetase does not exists as a tightly bound complex. The partially purified quinolinate synthetase is inhibited by physiological concetrations of NAD and NADH but not by NADP or NADPH.
Collapse
|
14
|
Inhibition of nicotinamide deamidase from Micrococcus lysodeikticus by analogues of nicotinamide. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/0020-711x(74)90027-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
15
|
Grunicke H, Keller HJ, Liersch M, Benaguid A. New aspects of the mechanism and regulation of pyridine nucleotide metabolism. ADVANCES IN ENZYME REGULATION 1974; 12:397-418. [PMID: 4376896 DOI: 10.1016/0065-2571(74)90024-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
16
|
MacGregor JT, Burkhalter A. Biliary excretion of nicotinamide riboside. A possible role in the regulation of hepatic pyridine nucleotide dynamics. Biochem Pharmacol 1973; 22:2645-58. [PMID: 4357893 DOI: 10.1016/0006-2952(73)90126-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
17
|
Bock KW, Matern S. Immunochemical studies on rat-liver microsomal NAD glycohydrolase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1973; 38:20-4. [PMID: 4359472 DOI: 10.1111/j.1432-1033.1973.tb03027.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
18
|
Kuwahara M, Chaykin S. Biosynthesis of Pyridine Nucleotides in Early Embryos of the Mouse (Mus musculus). J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)43676-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
19
|
|
20
|
Kakehi K, Shimoyama M, Tanigawa Y, Asamizu J, Ueda I. NAD glycohydrolase from the small intestine of the rat; purification, properties and possible role of the enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 268:506-17. [PMID: 4402079 DOI: 10.1016/0005-2744(72)90346-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|