The characterization of two reduced nicotinamide-adenine dinucleotide phosphate-linked aldehyde reductases from pig brain.
Ontology highlight
ABSTRACT:
SUBMITTER: Turner AJ
PROVIDER: S-EPMC1174514 | biostudies-other | 1972 Dec
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Reduction of the chromophores of mitochondrial NADH-ubiquinone reductase by NADPH reaches only 50% of the extent of reduction by NADH, monitored at 450 nm. This effect is due to autoxidation of an enzyme component at a higher rate than its reduction by NADPH.
| S-EPMC1163948 | biostudies-other
Project description:Here we report a new robust nicotinamide dinucleotide phosphate cofactor analog (carba-NADP+ ) and its acceptance by many enzymes in the class of oxidoreductases. Replacing one ribose oxygen with a methylene group of the natural NADP+ was found to enhance stability dramatically. Decomposition experiments at moderate and high temperatures with the cofactors showed a drastic increase in half-life time at elevated temperatures since it significantly disfavors hydrolysis of the pyridinium-N-glycoside bond. Overall, more than 27 different oxidoreductases were successfully tested, and a thorough analytical characterization and comparison is given. The cofactor carba-NADP+ opens up the field of redox-biocatalysis under harsh conditions.
| S-EPMC8252718 | biostudies-literature
Project description:The vascular endothelium plays an important role in the regulation of inflammatory responses after trauma and hemorrhage. Interactions of neutrophils with endothelial cells (ECs) contribute to the activation of specific EC responses involved in innate immunity. We have previously reported that oxidants derived from the neutrophil reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is a critical regulator to EC activation. Our objective was to test the role of neutrophil NADPH oxidase-derived oxidants in mediating and enhancing hemorrhagic shock (HS)-induced activation of lung endothelial NADPH oxidase. Mice were subjected to HS and neutrophil depletion. The mice were also replenished with the neutrophil from NADPH oxidase-deficient mice. The resultant activation of lung NADPH oxidase was analyzed. The in vivo studies were also recapitulated with in vitro neutrophil-EC coculture system. HS induces NADPH oxidase activation in neutrophils and lung through high-mobility group box 1/Toll-like receptor 4-dependent signaling. In neutropenic mice, shock-induced NADPH oxidase activation in the lung was reduced significantly, but was restored upon repletion with neutrophils obtained from wild-type mice subjected to shock, but not with neutrophils from shock mice lacking the gp91(phox) subunit of NADPH oxidase. The findings were recapitulated in mouse lung vascular ECs cocultured with neutrophils. The data further demonstrate that neutrophil-derived oxidants are key factors mediating augmented High mobility group box 1 (HMGB1)-induced endothelial NADPH oxidase activation through a Rac1-dependent, but p38 mitogen-activated protein kinase-independent, pathway. Oxidant signaling by neutrophil NADPH oxidase is an important determinant of activation of endothelial NADPH oxidase after HS.
| S-EPMC3095934 | biostudies-literature
Project description:Nonalcoholic fatty liver disease (NAFLD) represents a disease spectrum ranging from benign steatosis to life-threatening cirrhosis and hepatocellular carcinoma. Elevated levels of reactive oxygen species (ROS) and exacerbated inflammatory responses have been implicated in NAFLD progression. Nicotinamide adenine dinucleotide phosphate (reduced) oxidase 2 (NOX2; also known as gp91Phox), the main catalytic subunit of the nicotinamide adenine dinucleotide phosphate (reduced) oxidase complex, modulates ROS production, immune responsiveness, and pathogenesis of obesity-associated metabolic derangements. However, the role of NOX2 in the regulation of immune cell function and inflammatory vigor in NAFLD remains underdefined. Here, we demonstrate that obesogenic diet feeding promoted ROS production by bone marrow, white adipose tissue, and liver immune cells. Genetic ablation of NOX2 impeded immune cell ROS synthesis and was sufficient to uncouple obesity from glucose dysmetabolism and NAFLD pathogenesis. Protection from hepatocellular damage in NOX2-deficient mice correlated with reduced hepatic neutrophil, macrophage, and T-cell infiltration, diminished production of key NAFLD-driving proinflammatory cytokines, and an inherent reduction in T-cell polarization toward Th17 phenotype. Conclusion: Current findings demonstrate a crucial role of the NOX2-ROS axis in immune cell effector function and polarization and consequent NAFLD progression in obesity. Pharmacologic targeting of NOX2 function in immune cells may represent a viable approach for reducing morbidity of obesity-associated NAFLD pathogenesis. (Hepatology Communications 2018;2:546-560).
| S-EPMC5944572 | biostudies-literature
Project description:The displacement of NADH from cytoplasmic aldehyde dehydrogenase (EC 1.2.1.3) from sheep liver was studied by using NAD+, 1,10-phenanthroline, ADP-ribose, deamino-NAD+ and pyridine-3-aldehyde-adenine dinucleotide as displacing agents, by following the decrease in fluorescence as a function of time. The data obtained could be fitted by assuming two first-order processes were occurring, a faster process with an apparent rate constant of 0.85 +/- 0.20 s-1 and a relative amplitude of 60 +/- 10% and a slower process with an apparent rate constant of 0.20 +/- 0.05 s-1 and a relative amplitude of 40 +/- 10% (except for pyridine-3-aldehyde-adenine dinucleotide, where the apparent rate constant for the slow process was 0.05 s-1). The displacement rates did not change significantly when the pH was varied from 6.0 to 9.0. Kinetic data are also reported for the dependence of the rate of binding of NADH to the enzyme on the total concentration of NADH. Detailed arguments are presented based on the isolation and purification procedures, the equilibrium coenzyme-binding studies and the kinetic data, which lead to the following model for the release of NADH from the enzyme: (formula: see article). The parameters that best fit the data are: k + 1 = 0.2 s-1; k - 1 = 0.05 s-1; k + 2 = 0.8 s-1 and k - 2 = 5 X 10(5)litre-mol-1-s-1. The slow phase of the NADH release is similar to the steady-state turnover number for substrates such as acetaldehyde and propionaldehyde and appears to contribute significantly to the limitation of the steady-state rate.
| S-EPMC1164927 | biostudies-other
Project description:Nicotinamide adenine dinucleotide (NAD+) is a key redox compound in all living cells responsible for energy transduction, genomic integrity, life-span extension, and neuromodulation. Here, we report a new function of NAD+ as a molecular photocatalyst in addition to the biological roles. Our spectroscopic and electrochemical analyses reveal light absorption and electronic properties of two π-conjugated systems of NAD+. Furthermore, NAD+ exhibits a robust photostability under UV-Vis-NIR irradiation. We demonstrate photocatalytic redox reactions driven by NAD+, such as O2 reduction, H2O oxidation, and the formation of metallic nanoparticles. Beyond the traditional role of NAD+ as a cofactor in redox biocatalysis, NAD+ executes direct photoactivation of oxidoreductases through the reduction of enzyme prosthetic groups. Consequently, the synergetic integration of biocatalysis and photocatalysis using NAD+ enables solar-to-chemical conversion with the highest-ever-recorded turnover frequency and total turnover number of 1263.4 hour-1 and 1692.3, respectively, for light-driven biocatalytic trans-hydrogenation.
| S-EPMC6641943 | biostudies-literature
Project description:Reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate oxidase (NOX) is required for liver fibrosis. This study investigates the role of NOX in ROS production and the differential contribution of NOX from bone marrow (BM)-derived and non-BM-derived liver cells. Hepatic fibrosis was induced by bile duct ligation (BDL) for 21 days or by methionine-choline-deficient (MCD) diet for 10 weeks in wild-type (WT) mice and mice deficient in p47phox (p47phox knockout [KO]), a component of NOX. The p47phox KO chimeric mice were generated by the combination of liposomal clodronate injection, irradiation, and BM transplantation of p47phox KO BM into WT recipients and vice versa. Upon BDL, chimeric mice with p47phox KO BM-derived cells, including Kupffer cells, and WT endogenous liver cells showed a ?25% reduction of fibrosis, whereas chimeric mice with WT BM-derived cells and p47phox KO endogenous liver cells, including hepatic stellate cells, showed a ?60% reduction of fibrosis. In addition, p47phox KO compared to WT mice treated with an MCD diet showed no significant changes in steatosis and hepatocellular injury, but a ?50% reduction in fibrosis. Cultured WT and p47phox KO hepatocytes treated with free fatty acids had a similar increase in lipid accumulation. Free fatty acids promoted a 1.5-fold increase in ROS production both in p47phox KO and in WT hepatocytes.NOX in both BM-derived and non-BM-derived cells contributes to liver fibrosis. NOX does not play a role in experimental steatosis and the generation of ROS in hepatocytes, but exerts a key role in fibrosis.
| S-EPMC2947612 | biostudies-literature
Project description:Reperfusion after stroke leads to infiltration of inflammatory cells into the ischemic brain. Nicotinamide adenine dinucleotide phosphate oxidase (NOX2) is a major enzyme system that generates superoxide in immune cells. We studied the effect of NOX2 derived from the immune cells in the brain and in blood cells in experimental stroke.To establish whether NOX2 plays a role in brain ischemia, strokes were created in mice, then mice were treated with the NOX2 inhibitor apocynin or vehicle and compared to mice deficient in NOX2's gp91 subunit and their wild-type littermates. To determine whether NOX2 in circulating cells versus brain resident cells contribute to ischemic injury, bone marrow chimeras were generated by transplanting bone marrow from wild-type or NOX2-deficient mice into NOX2 or wild-type hosts, respectively.Apocynin and NOX2 deletion both significantly reduced infarct size, blood-brain barrier disruption, and hemorrhagic transformation of the infarcts, compared to untreated wild-type controls. This was associated with decreased matrix metalloproteinase 9 expression and reduced loss of tight junction proteins. NOX2-deficient mice receiving wild-type marrow had better outcomes compared to the wild-type mice receiving wild-type marrow. Interestingly, wild-type mice receiving NOX2-deficient marrow had even smaller infarct sizes and less hemorrhage than NOX2-deficient mice receiving wild-type marrow.This indicates that NOX2, whether present in circulating cells or brain resident cells, contributes to ischemic brain injury and hemorrhage. However, NOX2 from the circulating cells contributed more to the exacerbation of stroke than that from brain resident cells. These data suggest the importance of targeting the peripheral immune system for treatment of stroke.
| S-EPMC3205431 | biostudies-literature
Project description:Uterine fibroids are the most common benign tumor in women. The goal of this study was to investigate whether nicotinamide adenine dinucleotide phosphate oxidase (NOX), a major source of superoxide and subsequent oxidative stress, was differentially regulated in myometrium versus leiomyoma. Expression levels of NOXs1-5, dual oxidase (DUOX), DUOX2, NOX organizer (NOXO) 1, NOX activator 1, p47(phox), p67(phox), and p22(phox) were determined in cells treated with hypoxia by real-time reverse transcription-polymerase chain reaction, Western blot, and immunohistochemistry in tissues. Expression of NOX4 increased in fibroid compared to myometrial tissues and cells. The NOX2, DUOX1, and p67(phox) were higher while p22(phox) was lower in fibroid than that in myometrial cells. Hypoxia increased NOX4, DUOX1, and NOXO1 and decreased p22(phox) in myometrial and reduced DUOX1 in fibroid cells. The NOX1, NOX3, NOX5, and DUOX2 were undetectable. Fibroid cells are characterized by a unique NOX profile, which promotes a severe prooxidant state that may be responsible for their development. Targeting these subunits may be beneficial for future therapeutic interventions.
| S-EPMC5933080 | biostudies-literature
Project description:Hepatocyte apoptosis and activation of hepatic stellate cells (HSC) are critical events in fibrogenesis. We previously demonstrated that phagocytosis of apoptotic hepatocytes by HSC is profibrogenic. Based on this, as well as the observation that reduced nicotinamide adenine dinucleotide phosphate oxidase (NADPH) oxidase induction is central to fibrogenesis, our aim was to study the phagocytic NADPH oxidase NOX2.An in vivo phagocytosis model was developed by injecting wild type (wt) or NOX2(-/-) mice with lentiviral-green fluorescence protein (GFP) containing a hepatocyte-specific promoter, and adeno-tumor necrosis factor-related apoptosis-inducing ligand (ad-TRAIL). Fibrosis was evaluated in bile duct ligated (BDL) wt and NOX2(-/-) mice with or without gadolinium treatment. NOX2 expression was studied in human liver samples and in HSC isolated from fibrotic livers. The fibrogenic activity of NOX2 was assessed by collagen reporter assays.In the phagocytosis model, engulfment of GFP-labeled apoptotic bodies was seen, and the expression of ?-smooth muscle actin (?-SMA) and collagen I increased significantly in the wt but not in the NOX2(-/-) mice. Inhibiting apoptosis decreased the profibrogenic response. NOX2(-/-) animals exhibited significantly less fibrosis following BDL. Inactivating macrophages in wt BDL mice did not lower collagen production to the level observed in NOX2(-/-) mice, suggesting that NOX2-expressing HSC are important in fibrogenesis. NOX2 was up-regulated in HSC from fibrotic livers, and phagocytosis-induced NOX2 expression and activity were demonstrated. Based on reporter assays, production of NOX2-mediated reactive oxygen species directly induced collagen promoter activity in HSC.Apoptosis and phagocytosis of hepatocytes directly induce HSC activation and initiation of fibrosis. NOX2, the phagocytic NADPH oxidase, plays a key role in this process and in liver fibrogenesis in vivo.
| S-EPMC2949521 | biostudies-literature