Cofactor Nicotinamide Adenine Dinucleotide Research Articles

Extraction and Quantitation of Nicotinamide Adenine Dinucleotide Redox Cofactors.

Accurate analysis of dinucleotide redox cofactors nicotinamide adenine dinucleotide phosphate reduced (NADPH), nicotinamide adenine dinucleotide phosphate (NADP+), nicotinamide adenine dinucleotide reduced (NADH), and nicotinamide adenine dinucleotide (NAD+) from biological samples is important to understanding cellular redox homeostasis. In this study, we aimed to develop a simple protocol for quenching metabolism and extracting NADPH that avoids interconversion among the reduced forms and the oxidized forms. We compared seven different solvents for quenching and extraction of cultured mammalian cells and mouse tissues: a cold aqueous buffer commonly used in enzyme assays with and without detergent, hot aqueous buffer, and cold organic mixtures (80% methanol, buffered 75% acetonitrile, and acidic 40:40:20 acetonitrile:methanol:water with either 0.02 M or 0.1 M formic acid). Extracts were analyzed by liquid chromatography-mass spectrometry (LC-MS). To monitor the metabolite interconversion, cells were grown in 13C6-glucose medium, and unlabeled standards were spiked into the extraction solvents. Interconversion between the oxidized and reduced forms was substantial except for the enzyme assay buffer with detergent, 80% methanol and 40:40:20 acetonitrile:methanol:water, with the 0.1 M formic acid mix giving the least interconversion and best recoveries. Absolute NAD+, NADH, NADP+, and NADPH concentrations in cells and mouse tissues were measured with this approach. We found that the interconversion between the reduced and oxidized forms during extraction is a major barrier to accurately measuring NADPH/NADP+ and NADH/NAD+ ratios. Such interconversion can be monitored by isotope labeling cells and spiking NAD(P)(H) standards. Extraction with 40:40:20 acetonitrile:methanol:water with 0.1 M formic acid decreases interconversion and, therefore, is suitable for measurement of redox cofactor ratios using LC-MS. This solvent is also useful for general metabolomics. Samples should be neutralized immediately after extraction to avoid acid-catalyzed degradation. When LC-MS is not available and enzyme assays are accordingly used, inclusion of detergent in the aqueous extraction buffer reduces interconversion. Antioxid. Redox Signal. 28, 167-179.

Chromatographic analysis of tryptophan metabolites.

The kynurenine pathway generates multiple tryptophan metabolites called collectively kynurenines and leads to formation of the enzyme cofactor nicotinamide adenine dinucleotide. The first step in this pathway is tryptophan degradation, initiated by the rate‐limiting enzymes indoleamine 2,3‐dioxygenase, or tryptophan 2,3‐dioxygenase, depending on the tissue. The balanced kynurenine metabolism, which has been a subject of multiple studies in last decades, plays an important role in several physiological and pathological conditions such as infections, autoimmunity, neurological disorders, cancer, cataracts, as well as pregnancy. Understanding the regulation of tryptophan depletion provide novel diagnostic and treatment opportunities, however it requires reliable methods for quantification of kynurenines in biological samples with complex composition (body fluids, tissues, or cells). Trace concentrations, interference of sample components, and instability of some tryptophan metabolites need to be addressed using analytical methods. The novel separation approaches and optimized extraction protocols help to overcome difficulties in analyzing kynurenines within the complex tissue material. Recent developments in chromatography coupled with mass spectrometry provide new opportunity for quantification of tryptophan and its degradation products in various biological samples. In this review, we present current accomplishments in the chromatographic methodologies proposed for detection of tryptophan metabolites and provide a guide for choosing the optimal approach.

Intracellular Transfer Hydrogenation Mediated by Unprotected Organoiridium Catalysts.

In the present work, we show for the first time that the conversion of aldehydes to alcohols can be achieved using "unprotected" iridium transfer hydrogenation catalysts inside living cells. The reactions were observed in real time by confocal fluorescence microscopy using a Bodipy fluorogenic substrate. We propose that the reduced cofactor nicotinamide adenine dinucleotide (NADH) is a possible hydride source inside the cell based on studies using pyruvate as a cellular redox modulator. We expect that this biocompatible reductive chemistry will be broadly useful to practitioners working at the interface of chemistry and the life sciences.

Escaping Death: Mitochondrial Redox Homeostasis in Cancer Cells

Reactive oxygen species (ROS) are important signaling molecules that act through the oxidation of nucleic acids, proteins, and lipids. Several hallmarks of cancer, including uncontrolled proliferation, angiogenesis, and genomic instability, are promoted by the increased ROS levels commonly found in tumor cells. To counteract excessive ROS accumulation, oxidative stress, and death, cancer cells tightly regulate ROS levels by enhancing scavenging enzymes, which are dependent on the reducing cofactor nicotinamide adenine dinucleotide phosphate (NADPH). This review focuses on mitochondrial ROS homeostasis with a description of six pathways of NADPH production in mitochondria and a discussion of the possible strategies of pharmacological intervention to selectively eliminate cancer cells by increasing their ROS levels.

NAD+ augmentation ameliorates acute pancreatitis through regulation of inflammasome signalling

Acute pancreatitis (AP) is a complicated disease without specific drug therapy. The cofactor nicotinamide adenine dinucleotide (NAD+) is an important regulator of cellular metabolism and homeostasis. However, it remains unclear whether modulation of NAD+ levels has an impact on caerulein-induced AP. Therefore, in this study, we investigated the effect of increased cellular NAD+ levels on caerulein-induced AP. We demonstrated for the first time that the activities and expression of SIRT1 were suppressed by reduction of intracellular NAD+ levels and the p53-microRNA-34a pathway in caerulein-induced AP. Moreover, we confirmed that the increase of cellular NAD+ by NQO1 enzymatic action using the substrate β-Lapachone suppressed caerulein-induced AP with down-regulating TLR4-mediated inflammasome signalling, and thereby reducing the inflammatory responses and pancreatic cell death. These results suggest that pharmacological stimulation of NQO1 could be a promising therapeutic strategy to protect against pathological tissue damage in AP.

On the conceptual design of a partitioning technology for the bioconversion of (+)-valencene to (+)-nootkatone on whole cells: Experimentation and modelling

The conceptual design of a four-phase partitioning bioreactor to produce (+)-nootkatone out of (+)-valencene on whole cells of Yarrowia lipolytica 2.2ab requires yet from the proper modelling and analysis of those phenomena limiting the bioconversion in this reaction system. This work is aimed at modelling this partitioning bioreactor. In this sense, a pseudo heterogeneous model is, particularly, developed by using experiments under biotic and abiotic conditions. First, in a two-phase abiotic reactor, interfacial mass transfer in absence of reaction is characterized by determining the effective interfacial coefficients for sequiterpenes (kiAdp) and for oxygen (KLa). Then, kinetics and cell deactivation are characterized by developing the corresponding models in a three-phase biotic reactor; two types of whole cells are evaluated here, namely Yarrowia lipolytica 2.2ab untreated and treated with cetyl trimethylammonium bromite (CTAB) to expel possible reaction intermediate out of the cell and with niacin (vitamin B3) to favour the regeneration of the cofactor nicotinamide adenine dinucleotide phosphate (NADPH+). It is worth stressing that kinetic and cell deactivation models account for (+)-valencene inhibition, (+)-nootkatone inhibition and oxygen inactivation. To this end, the partitioning four-phase reactor model, making use of the calculated mass transport, kinetic and deactivation parameters, is able to describe observations and predict enzyme coverage profiles at different cell activity scenarios. A parametric sensitivity study allows the identification of volume disperse phase fraction (ϕ=0.2–0.5), agitation rate (200–400rpm) and airflow rate (0.5–1vvm) as the main operational variables influencing the biological conversion of (+)-valencene. At studied conditions, the highest production rate of (+)-nootkatone is obtained at 300rpm, 1vvm and, essentially, at ϕ=0.35.

An Insight Into Structure, Function, and Expression Analysis of 3-Hydroxy-3-Methylglutaryl-CoA Reductase of

Citronella ( Cymbopogon winterianus ) is one of the richest sources of high-value isoprenoid aromatic compounds used as flavour, fragrance, and therapeutic elements. These isoprenoid compounds are synthesized by 2 independent pathways: mevalonate pathway and 2-C-methyl-d-erythritol-4-phosphate pathway. Evidence suggests that 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) is a rate-controlling enzyme for the synthesis of variety of isoprenoids. This study reports the isolation, characterization, and tissue-specific expression analysis of HMGR from citronella. The modelled HMGR is a class I type of HMGR enzyme with 3-domain architecture. The active site comprises a cofactor (nicotinamide adenine dinucleotide phosphate) and the substrate-binding motifs. The real-time and quantitative reverse transcription-polymerase chain reaction results revealed equal expression level in both leaf sheath and root tissue. The results from our study shall be a valuable resource for future molecular intervention to alter the metabolic flux towards improvement of key active ingredient in this important medicinal plant.

Biocatalytic cofactor recycled efficiently

Oxidoreductase enzymes are used extensively as biocatalysts for industrial and academic reactions, including pharmaceutical synthesis. But they almost exclusively require expensive cofactors such as NADP+, the oxidized form of the biological cofactor nicotinamide adenine dinucleotide phosphate. The reagent currently costs about $22,000 per mole. Enzymes that can recycle it from its reduced form, NADPH, have drawbacks that have limited their use, such as low activity, unwanted by-product generation, and short lifetimes. Guided by nature, which uses an NADP+-producing glutathione reductase system to maintain a reducing environment within cells, researchers have now developed a similar system for regenerating NADP+ from NADPH. Rudolf K. Allemann of Cardiff University and coworkers devised the system, which uses an organic-disulfide oxidizing agent and bacterial glutaredoxin and glutathione reductase to regenerate NADP+ (ACS Catal. 2016, DOI: 10.1021/acscatal.6b03061). The primary recurrent cost is for the inexpensive organic disulfides, so the process could reduce the price of NADP+

An Insight Into Structure, Function, and Expression Analysis of 3-Hydroxy-3-Methylglutaryl-CoA Reductase of Cymbopogon winterianus.

Citronella (Cymbopogon winterianus) is one of the richest sources of high-value isoprenoid aromatic compounds used as flavour, fragrance, and therapeutic elements. These isoprenoid compounds are synthesized by 2 independent pathways: mevalonate pathway and 2-C-methyl-d-erythritol-4-phosphate pathway. Evidence suggests that 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) is a rate-controlling enzyme for the synthesis of variety of isoprenoids. This study reports the isolation, characterization, and tissue-specific expression analysis of HMGR from citronella. The modelled HMGR is a class I type of HMGR enzyme with 3-domain architecture. The active site comprises a cofactor (nicotinamide adenine dinucleotide phosphate) and the substrate-binding motifs. The real-time and quantitative reverse transcription-polymerase chain reaction results revealed equal expression level in both leaf sheath and root tissue. The results from our study shall be a valuable resource for future molecular intervention to alter the metabolic flux towards improvement of key active ingredient in this important medicinal plant.

Robust l-malate bienzymatic biosensor to enable the on-site monitoring of malolactic fermentation of red wines

Monitoring the malolactic fermentation process is strictly required to guarantee the sensorial quality and freshness of red wines. This could be achieved by in-field and real-time continuous measurements of l-malate concentration in the fermentation tanks. The potential of a miniaturized amperometric bienzymatic biosensor as an analytical tool to be applied in such scenario is described in this paper. The biosensor comprises a thin-film gold electrode as transducer, malate dehydrogenase (MDH) and diaphorase (DP) enzymes together with nicotinamide adenine dinucleotide (NAD+) cofactor as the selective receptor and an adequate redox mediator to record the corresponding amperometric signal. Three different biosensor architectures are studied, whose main differences lie in the immobilization of the different chemical components onto the electrode surface. In all cases a fast-electrosynthethized polypyrrole (PPy) membrane is generated for this purpose. The experimental conditions are optimized and the best architecture shows a sensitivity of 1365 ± 110 mA M−1 cm−2 and a detection limit of 6.3 × 10−8 M in a concentration range of 1 × 10−7 M – 1 × 10−6 M. The biosensor presents an excellent working stability as it retains above 90% of its sensitivity after 37 days, thus enabling the monitoring of the malolactic fermentation of three red wines. The obtained results show excellent agreement with the standard colorimetric method.

TMIC-26. EXPLORATION OF TRYPTOPHAN METABOLISM VIA THE KYNURENINE PATHWAY IN HUMAN GLIOMAS

The kynurenine pathway (KP) is responsible for a majority of the catabolism of the essential amino acid tryptophan, and recently was implicated in the pathophysiology of human gliomas. The KP generates various active metabolites, is the main source of the essential co-factor nicotinamide adenine dinucleotide (NAD+), and plays a pivotal role in promoting anti-tumor immune suppression through depleting local tryptophan and causing T-cell growth arrest. Kynurenine, a KP metabolite, was recently discovered to be an endogenous ligand of the aryl hydrocarbon receptor (AHR), a transcription factor associated with carcinogenesis. We hypothesized that higher-grade gliomas will have a more dysregulated KP, and therefore sought to examine the potential differences in KP expression in low- versus high-grade gliomas. Active tumor tissue was acquired immediately following microsurgical resection, and the tumor was dissociated into a single-cell suspension for performance of in vitro experiments. Immunohistochemical staining of Grade II, III, and IV glioma (glioblastoma: GBM) patient tumor sections with antibodies specific for: human indoleamine 2,3-dioxygenase (IDO) 1; IDO2; tryptophan 2,3-dioxgyenase (TDO2); kynureninase; kynurenine 3-monooxygenase (KMO); and AHR. Tissue sections were scored from 0-3 based on staining intensity. Patient-derived tumor cell cultures were treated with commercially available small molecule inhibitors for IDO1 (epacadostat), IDO2 (chloroquine), TDO2 (680C91), KMO (Ro61-8048), and AHR (CH-223191) for 48-hours. GBM tissues show significantly (p<0.001, ANOVA) higher levels of KP enzymes and AHR compared to Grade II and Grade III tissues. In vitro drug treatment showed markedly diminished cell proliferation via MTT assay in response to chloroquine and CH-223191. The increased staining of KP enzymes, as well as the diminished proliferation with the inhibitors, suggests that the KP plays a role in malignant gliomas, and may offer novel therapeutic targets for a patient population with highly limited treatment options.

Crystal Structures of Quinolinate Synthase in Complex with a Substrate Analogue, the Condensation Intermediate, and Substrate-Derived Product.

The enzyme NadA catalyzes the synthesis of quinolinic acid (QA), the precursor of the universal nicotinamide adenine dinucleotide (NAD) cofactor. Here, we report the crystal structures of complexes between the Thermotoga maritima (Tm) NadA K219R/Y107F variant and (i) the first intermediate (W) resulting from the condensation of dihydroxyacetone phosphate (DHAP) with iminoaspartate and (ii) the DHAP analogue and triose-phosphate isomerase inhibitor phosphoglycolohydroxamate (PGH). In addition, using the TmNadA K219R/Y21F variant, we have reacted substrates and obtained a crystalline complex between this protein and the QA product. We also show that citrate can bind to both TmNadA K219R and its Y21F variant. The W structure indicates that condensation causes dephosphorylation. We propose that catalysis by the K219R/Y107F variant is arrested at the W intermediate because the mutated protein is unable to catalyze its aldo-keto isomerization and/or cyclization that ultimately lead to QA formation. Intriguingly, PGH binds to NadA with its phosphate group at the site where the carboxylate groups of W also bind. Our results shed significant light on the mechanism of the reaction catalyzed by NadA.

Correlating two-photon excited fluorescence imaging of breast cancer cellular redox state with seahorse flux analysis of normalized cellular oxygen consumption.

Two-photon excited fluorescence (TPEF) imaging of the cellular cofactors nicotinamide adenine dinucleotide and oxidized flavin adenine dinucleotide is widely used to measure cellular metabolism, both in normal and pathological cells and tissues. When dual-wavelength excitation is used, ratiometric TPEF imaging of the intrinsic cofactor fluorescence provides a metabolic index of cells—the “optical redox ratio” (ORR). With increased interest in understanding and controlling cellular metabolism in cancer, there is a need to evaluate the performance of ORR in malignant cells. We compare TPEF metabolic imaging with seahorse flux analysis of cellular oxygen consumption in two different breast cancer cell lines (MCF-7 and MDA-MB-231). We monitor metabolic index in living cells under both normal culture conditions and, for MCF-7, in response to cell respiration inhibitors and uncouplers. We observe a significant correlation between the TPEF-derived ORR and the flux analyzer measurements (R=0.7901, p<0.001). Our results confirm that the ORR is a valid dynamic index of cell metabolism under a range of oxygen consumption conditions relevant for cancer imaging.

A Disposable paper breathalyzer with an alcohol sensing organic electrochemical transistor.

Breathalyzers estimate Blood Alcohol Content (BAC) from the concentration of ethanol in the breath. Breathalyzers are easy to use but are limited either by their high price and by environmental concerns, or by a short lifetime and the need for continuous recalibration. Here, we demonstrate a proof-of-concept disposable breathalyzer using an organic electrochemical transistor (OECT) modified with alcohol dehydrogenase (ADH) as the sensor. The OECT is made with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and is printed on paper. ADH and its cofactor nicotinamide adenine dinucleotide (NAD+) are immobilized onto the OECT with an electrolyte gel. When the OECT-breathalyzer is exposed to ethanol vapor, the enzymatic reaction of ADH and ethanol transforms NAD+ into NADH, which causes a decrease in the OECT source drain current. In this fashion, the OECT-breathalyzer easily detects ethanol in the breath equivalent to BAC from 0.01% to 0.2%. The use of a printed OECT may contribute to the development of breathalyzers that are disposable, ecofriendly, and integrated with wearable devices for real-time BAC monitoring.

A novel reagentless glutamate microband biosensor for real-time cell toxicity monitoring

A reagentless glutamate biosensor was applied to the determination of glutamate released from liver hepatocellular carcinoma cells (HepG2) in response to toxic challenge from various concentrations of paracetamol. A screen printed carbon electrode (SPCE) containing the electrocatalyst Meldola's Blue (MB-SPCE) served as the electron mediator for the oxidation of NADH.A mixture of the enzyme glutamate dehydrogenase (GLDH), cofactor nicotinamide adenine dinucleotide (NAD+) and the biopolymer chitosan (CHIT) were drop-coated onto the surface of the transducer (MB-SPCE) in a simple one step fabrication process.The reagentless biosensor was used with amperometry in stirred solution at an applied potential of +0.1 V (vs. Ag/AgCl). All experiments were carried out at the following conditions: pH 7, temperature 37 °C, atmosphere 5% CO2.The linear range of the device was found to be 25–125 μM in phosphate buffer (75 mM, containing 0.05 M NaCl) and 25–150 μM in cell culture medium. The limits of detection (LOD) were found to be 1.2 μM and 4.2 μM based on three times signal to noise, using PBS and culture medium respectively. The sensitivity was calculated to be 106 nA μM−1 cm−2 and 210 nA μM−1 cm−2 in PBS and cell medium respectively. The response time was ∼60 s in an agitated solution.HepG2 cells were exposed to various concentrations of paracetamol (1 mM, 5 mM and 10 mM) in order to investigate the drug-induced release of glutamate into the culture medium in real time. Two toxicity studies were investigated using different methods of exposure and analysis.The first method consisted of a single measurement of the glutamate concentration, using the method of standard addition, after 24 h incubation. The concentrations of glutamate were found to be 52 μM, 93 μM and 177 μM, released on exposure to 1 mM, 5 mM and 10 mM paracetamol respectively.The second method involved the continuous monitoring of glutamate released from HepG2 cells upon exposure to paracetamol over 8 h. The concentrations of glutamate released in the presence of 1 mM, 5 mM and 10 mM paracetamol, increased in proportion to the drug concentration, ie: 16 μM, 28 μM and 62 μM respectively. This result demonstrates the feasibility of using this approach to monitor early metabolic changes after exposure to a model toxic compound.

Quantification of ethanol in plasma by electrochemical detection with an unmodified screen printed carbon electrode

Simple, rapid and accurate detection of ethanol concentration in blood is very crucial in the diagnosis and management of potential acute ethanol intoxication patients. A novel electrochemical detection method was developed for the quantification of ethanol in human plasma with disposable unmodified screen-printed carbon electrode (SPCE) without sample preparation procedure. Ethanol was detected indirectly by the reaction product of ethanol dehydrogenase (ADH) and cofactor nicotinamide adenine dinucleotide (NAD+). Method validation indicated good quantitation precisions with intra-day and inter-day relative standard deviations of ≤9.4% and 8.0%, respectively. Ethanol concentration in plasma is linear ranging from 0.10 to 3.20 mg/mL, and the detection limit is 40.0 μg/mL (S/N > 3). The method shows satisfactory correlation with the reference method of headspace gas chromatography in twenty human plasma samples (correlation coefficient 0.9311). The proposed method could be applied to diagnose acute ethanol toxicity or ethanol-related death.

Synthesis of 5'-NAD-Capped RNA.

In prokaryotic organisms, certain regulatory RNAs have recently been found to be linked to the ubiquitous redox cofactor nicotinamide adenine dinucleotide (NAD) at their 5'-ends. Biochemical and structural investigations of this new caplike RNA modification require synthetic access to pure NAD-RNA. Here we report a chemoenzymatic approach to generate 5'-NAD-capped RNA in high yields and purity under mild conditions. This approach uses unprotected 5'-monophosphate RNA synthesized either chemically or enzymatically, 5',5'-pyrophosphate bond formation by phosphorimidazolide chemistry, and an enzymatic cleanup step. Thus, 5'-NAD-modified RNA can be synthesized independent of length, structure, and nucleotide sequence.

NAD+ Supplementation Attenuates Methylmercury Dopaminergic and Mitochondrial Toxicity in Caenorhabditis Elegans.

Methylmercury (MeHg) is a neurotoxic contaminant of our fish supply that has been linked to dopaminergic (DAergic) dysfunction that characterizes Parkinson's disease. We have previously shown that MeHg causes both morphological and behavioral changes in the Caenorhabditis elegans DAergic neurons that are associated with oxidative stress. We were therefore interested in whether the redox sensitive cofactor nicotinamide adenine dinucleotide (NAD(+)) may be affected by MeHg and whether supplementation of NAD( + )may prevent MeHg-induced toxicities. Worms treated with MeHg showed depletion in cellular NAD( + )levels, which was prevented by NAD( + )supplementation prior to MeHg treatment. NAD( + )supplementation also prevented DAergic neurodegeneration and deficits in DAergic-dependent behavior upon MeHg exposure. In a mutant worm line that cannot synthesize NAD( + )from nicotinamide, MeHg lethality and DAergic behavioral deficits were more sensitive to MeHg than wildtype worms, demonstrating the importance of NAD( + )in MeHg toxicity. In wildtype worms, NAD( + )supplementation provided protection from MeHg-induced oxidative stress and mitochondrial dysfunction. These data show the importance of NAD( + )levels in the response to MeHg exposure. NAD( + )supplementation may be beneficial for MeHg-induced toxicities and preventing cellular damage involved in Parkinson's disease.

Functional surface engineering of quantum dot hydrogels for selective fluorescence imaging of extracellular lactate release

Selective and sensitive detection of extracellular lactate is of fundamental significance for studying the metabolic alterations in tumor progression. Here we report the rational design and synthesis of a quantum-dot-hydrogel-based fluorescent probe for biosensing and bioimaging the extracellular lactate. By surface engineering the destabilized quantum dot sol with Nile Blue, the destabilized Nile-Blue-functionalized quantum dot sol cannot only self-assemble forming quantum dot hydrogel but also monitor lactate in the presence of nicotinamide adenine dinucleotide cofactor and lactate dehydrogenase through fluorescence resonance energy transfer. Notably, the surface engineered quantum dot hydrogel show high selectivity toward lactate over common metal ions, amino acids and other small molecules that widely coexist in biological system. Moreover, the destabilized Nile-Blue-functionalized quantum dots can encapsulate isolated cancer cells when self-assembled into a hydrogel and thus specifically detect and image the extracellular lactate metabolism. By virtue of these properties, the functionalized quantum dot hydrogel was further successfully applied to monitor the effect of metabolic agents.

New Therapeutic Concept of NAD Redox Balance for Cisplatin Nephrotoxicity.

Cisplatin is a widely used chemotherapeutic agent for the treatment of various tumors. In addition to its antitumor activity, cisplatin affects normal cells and may induce adverse effects such as ototoxicity, nephrotoxicity, and peripheral neuropathy. Various mechanisms such as DNA adduct formation, mitochondrial dysfunction, oxidative stress, and inflammatory responses are closely associated with cisplatin-induced nephrotoxicity; however, the precise mechanism remains unclear. The cofactor nicotinamide adenine dinucleotide (NAD+) has emerged as a key regulator of cellular energy metabolism and homeostasis. Recent studies have demonstrated associations between disturbance in intracellular NAD+ levels and clinical progression of various diseases through the production of reactive oxygen species and inflammation. Furthermore, we demonstrated that reduction of the intracellular NAD+/NADH ratio is critically involved in cisplatin-induced kidney damage through inflammation and oxidative stress and that increase of the cellular NAD+/NADH ratio suppresses cisplatin-induced kidney damage by modulation of potential damage mediators such as oxidative stress and inflammatory responses. In this review, we describe the role of NAD+ metabolism in cisplatin-induced nephrotoxicity and discuss a potential strategy for the prevention or treatment of cisplatin-induced adverse effects with a particular focus on NAD+-dependent cellular pathways.