ovalbumin and 3-nitrotyrosine

3-Nitrotyrosine (3-NT) is thought to be a relevant biomarker of nitrosative stress which is associated with many inflammatory and chronic diseases. It is necessary to develop confidential method for specific and sensitive 3-NT detection. In this paper, on the basis of anti-3-NT specific antibody, we developed a label-free indirect competitive surface plasmon resonance (SPR) immunosensor and ELISA for the detection of 3-NT. Under the optimized conditions, the SPR immunosensor can obtain a linear range of 0.17-6.07 μg/mL and a limit of detection (LOD) of 0.12 μg/mL while the ELISA can reach 0.33-9.94 μg/mL and a LOD of 0.24 μg/mL.The selectivity of 3-NT was also testified by six kinds of amino acid analogues. Besides, the developed SPR immunosensor was compared thoroughly with a conventional ELISA in spiked analysis of urine samples. Good recoveries and correlation between these two methods were observed (R

Topics: Antibodies; Antigens; Biosensing Techniques; Cross Reactions; Humans; Immunoassay; Limit of Detection; Ovalbumin; Surface Plasmon Resonance; Tyrosine

Reactive oxygen species produced during allergic inflammation are key players of the pathophysiology of asthma, leading to oxidative tissue injury and inactivation of endogenous manganese superoxide dismutase (MnSOD). On this ground, removal of excess superoxide anion by scavenger molecules would be beneficial and protective. Here we show that a novel manganese(II)-containing polyamine-polycarboxylic compound, termed Mn(II)(Me(2)DO2A), with potent superoxide dismuting properties decreases the respiratory and histopathological lung abnormalities due to allergen inhalation in a model of ovalbumin (OA)-induced allergic asthma-like reaction in sensitized guinea pigs. Severe respiratory dysfunction in response to OA aerosolic challenge arose rapidly in the sensitized animals and was accompanied by bronchoconstriction, alveolar hyperinflation, mast cell activation, increased leukocyte infiltration (evaluated by myeloperoxidase assay), oxidative lung tissue injury (evaluated by the thiobarbituric-acid-reactive substances and nitrotyrosine immunostaining), decay of endogenous MnSOD activity, production of pro-inflammatory prostaglandins, and lung cell apoptosis. Treatment with Mn(II)(Me(2)DO2A) (15mg/kg, given 1h before allergen challenge), but not the inactive congener Zn(II)(Me(2)DO2A) lacking redox-active metal site, significantly attenuated all the above functional, histopathological and biochemical parameters of allergic inflammation and restored the levels of MnSOD activity. In conclusion, our findings support the potential therapeutic use of Mn(II)(Me(2)DO2A) as novel superoxide scavenger drug in asthma and anaphylactic reactions.

Topics: Allergens; Anaphylaxis; Animals; Anti-Asthmatic Agents; Apoptosis; Asthma; Bronchoconstriction; Caspase 3; Free Radical Scavengers; Guinea Pigs; Male; Mast Cells; Organometallic Compounds; Ovalbumin; Peroxidase; Superoxides; Thiobarbituric Acid Reactive Substances; Tyrosine

For kinetic studies of protein nitration reactions, we have developed a method for the quantification of nitrotyrosine residues in protein molecules by liquid chromatography coupled to a diode array detector of ultraviolet-visible absorption. Nitrated bovine serum albumin (BSA) and nitrated ovalbumin (OVA) were synthesized and used as standards for the determination of the protein nitration degree (ND), which is defined as the average number of nitrotyrosine residues divided by the total number of tyrosine residues in a protein molecule. The obtained calibration curves of the ratio of chromatographic peak areas of absorbance at 357 and at 280 nm vs. nitration degree are nearly the same for BSA and OVA (relative deviations <5%). They are near-linear at low ND (< 0.1) and can be described by a second-order polynomial fit up to ND=0.5 (R2>0.99). A change of chromatographic column led to changes in absolute peak areas but not in the peak area ratios and related calibration functions, which confirms the robustness of the analytical method. First results of laboratory experiments confirm that the method is applicable for the investigation of the reaction kinetics of protein nitration. The main advantage over alternative methods is that nitration degrees can be efficiently determined without hydrolysis or digestion of the investigated protein molecules.

Topics: Animals; Cattle; Chromatography, High Pressure Liquid; Kinetics; Ovalbumin; Proteins; Serum Albumin, Bovine; Tyrosine

Reactive oxygen and nitrogen species (RONS) are implicated in the pathogenesis of several autoimmune diseases. Also, increased lipid peroxidation and protein nitration are reported in systemic autoimmune diseases. Lipid peroxidation-derived aldehydes (LPDAs) such as malondialdehyde (MDA) and 4-hydroxynonenal (HNE) are highly reactive and bind proteins covalently, but their potential to elicit an autoimmune response and contribution to disease pathogenesis remain unclear. Similarly, nitration of protein could also contribute to disease pathogenesis. To assess the status of lipid peroxidation and/or RONS, autoimmune-prone female MRL+/+ mice (5-week old) were treated with trichloroethene (TCE), an environmental contaminant known to induce autoimmune response, for 48 weeks (0.5mg/ml via drinking water), and formation of antibodies to LPDA-protein adducts was followed in the sera of control and TCE-treated mice. TCE treatment led to greater formation of both anti-MDA- and -HNE-protein adduct antibodies and higher serum iNOS and nitrotyrosine levels. The increase in TCE-induced oxidative stress was associated with increases in anti-nuclear-, anti-ssDNA- and anti-dsDNA-antibodies. These findings suggest that TCE exposure not only leads to oxidative/nitrosative stress, but is also associated with induction/exacerbation of autoimmune response in MRL+/+ mice. Further interventional studies are needed to establish a causal role of RONS in TCE-mediated autoimmunity.

Topics: Aldehydes; Animals; Autoantibodies; Environmental Pollutants; Female; Lipid Peroxidation; Liver; Malondialdehyde; Mice; Mice, Inbred MRL lpr; Nitric Oxide Synthase Type II; Ovalbumin; Oxidative Stress; Solvents; Trichloroethylene; Tyrosine

Reactive oxygen species and reactive nitrogen species produced by epithelial and inflammatory cells are key mediators of the chronic airway inflammation of asthma. Detection of 3-nitrotyrosine in the asthmatic lung confirms the presence of increased reactive oxygen and nitrogen species, but the lack of identification of modified proteins has hindered an understanding of the potential mechanistic contributions of nitration/oxidation to airway inflammation. In this study, we applied a proteomic approach, using nitrotyrosine as a marker, to evaluate the oxidation of proteins in the allergen-induced murine model of asthma. Over 30 different proteins were targets of nitration following allergen challenge, including the antioxidant enzyme catalase. Oxidative modification and loss of catalase enzyme function were seen in this model. Subsequent investigation of human bronchoalveolar lavage fluid revealed that catalase activity was reduced in asthma by up to 50% relative to healthy controls. Analysis of catalase isolated from asthmatic airway epithelial cells revealed increased amounts of several protein oxidation markers, including chloro- and nitrotyrosine, linking oxidative modification to the reduced activity in vivo. Parallel in vitro studies using reactive chlorinating species revealed that catalase inactivation is accompanied by the oxidation of a specific cysteine (Cys(377)). Taken together, these studies provide evidence of multiple ongoing and profound oxidative reactions in asthmatic airways, with one early downstream consequence being catalase inactivation. Loss of catalase activity likely amplifies oxidative stress, contributing to the chronic inflammatory state of the asthmatic airway.

Topics: Adult; Animals; Asthma; Catalase; Cell Line; Electrophoresis, Gel, Two-Dimensional; Enzyme Activation; Epithelial Cells; Gene Expression Regulation, Enzymologic; Humans; Immunohistochemistry; Mice; Mice, Inbred BALB C; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Ovalbumin; Oxidation-Reduction; Proteome; Proteomics; Reactive Nitrogen Species; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tyrosine

Recent investigations have shown that proteins, including Bet v 1a, are nitrated by exposure to polluted urban air. We have investigated immunogenic and allergenic properties of in vitro nitrated allergens in in vivo models.. Untreated and nitrated samples of ovalbumin or Bet v 1a were compared for their ability to stimulate proliferation and cytokine secretion in splenocytes from DO11.10 or from sensitized BALB/c mice, and for their ability to induce specific immunoglobulin (Ig)G1, IgG2a and IgE in sensitized mice. Additionally, sera from birch pollen-allergic individuals were analysed for IgE and IgG specific for nitrated Bet v 1a.. Upon splenocyte stimulation with nitrated as compared with unmodified allergens, proliferation as well as interleukin 5 and interferon-gamma production were enhanced. Sera of mice sensitized with nitrated allergens showed elevated levels of specific IgE, IgG1 and IgG2a, compared with sera from mice sensitized with unmodified allergens. Moreover, cross-reactivity of antibodies against unrelated, nitrated allergens was observed in mice. We also found higher amounts of functional, specific IgE against nitrated than against untreated Bet v 1a in sera from birch pollen-allergic patients.. Our findings suggest that nitration enhances allergic responses, which may contribute to an increased prevalence of allergic diseases in polluted urban environments.

Topics: Allergens; Animals; Antigens, Plant; Cell Proliferation; Female; Food Hypersensitivity; Mice; Mice, Inbred BALB C; Ovalbumin; Plant Proteins; Protein Processing, Post-Translational; Spleen; Tetranitromethane; Tyrosine

Poly(ADP-ribose) polymerase (PARP) plays an important role in tissue injury in conditions associated with oxidative stress and inflammation. Because asthma is a chronic inflammatory disorder of the airways, we designed the present experimental study to evaluate the effects of PARP inhibition on allergen-induced asthma-like reaction in ovalbumin-sensitized guinea pigs. Cough and dyspnea in response to ovalbumin aerosol were absent in naive guinea pigs, whereas they became severe in the sensitized animals. In the latter ones, ovalbumin aerosol also induced a rapid increase in PARP activity, bronchiolar constriction, pulmonary air space inflation, mast cell degranulation, poly(ADP-ribose) and nitrotyrosine immunostaining, myeloperoxidase activity, and malondialdehyde in lung tissue, as well as a rise in the amounts of nitrites and tumor necrosis factor-alpha in bronchoalveolar lavage fluid. Pretreatment with the PARP inhibitors 3-aminobenzamide (10 mg/kg b.wt.) or 5-aminoisoquinolinone (0.5 mg/kg b.wt.) given i.p. 3 h before ovalbumin challenge significantly reduced the severity of cough and the occurrence of dyspnea and delayed the onset of respiratory abnormalities. Both PARP inhibitors were also able to prevent the above morphological and biochemical changes of lung tissue or bronchoalveolar lavage fluid induced by ovalbumin challenge. Conversely, p-aminobenzoic acid, the inactive analog of 3-aminobenzamide, had no effects.

Topics: Allergens; Animals; Anti-Asthmatic Agents; Asthma; Benzamides; Bronchoalveolar Lavage Fluid; Enzyme Inhibitors; Guinea Pigs; Immunohistochemistry; Isoquinolines; Lung; Male; Malondialdehyde; Mast Cells; Nitric Oxide; Ovalbumin; Peroxidase; Poly(ADP-ribose) Polymerase Inhibitors; Respiratory Mechanics; Tumor Necrosis Factor-alpha; Tyrosine

Nitric oxide (NO) shows proinflammatory actions mainly via reactive nitrogen species (RNS) formation through superoxide- and peroxidase-dependent mechanisms. The purpose of this study was to examine the role of inducible NO synthase (iNOS) in RNS production, airway hyperresponsiveness, and inflammation after allergen challenge. Ovalbumin (OVA)-sensitised, iNOS-deficient and wild-type mice were used. RNS production was assessed by nitrotyrosine (NT) immunoreactivity in the airways. Airway inflammation and responsiveness were evaluated by eosinophil accumulation and methacholine (i.v.) challenge, respectively. In wild-type mice, OVA-inhalation challenge increased iNOS immunoreactivity in airway epithelial cells as well as iNOS protein measured by Western blotting. The total amounts of nitrite and nitrate in bronchoalveolar lavage (BAL) fluid were increased, and NT immunoreactivity was also observed abundantly in airway inflammatory cells. In iNOS-deficient mice, both iNOS expression and NT formation were completely abolished, and the total amounts of nitrite and nitrate in BAL fluid were significantly decreased. In contrast, OVA-induced airway eosinophil recruitment and hyperresponsiveness were observed almost equally in wild-type and iNOS-deficient mice. These data suggest that reactive nitrogen species production after allergic reaction occurs totally via inducible nitric oxide synthase-dependent pathways. Allergen-mediated airway eosinophil recruitment and hyperresponsiveness appear to be independent of reactive nitrogen species production.

Topics: Allergens; Animals; Bronchi; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Eosinophils; Immunization; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitrates; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrites; Ovalbumin; Reactive Nitrogen Species; Respiratory Hypersensitivity; Tyrosine

Immunohistochemical artifacts for nitrotyrosine were investigated in eosinophils with regard to fixatives. Immunoreactivity for nitrotyrosine was revealed in separated eosinophils and in gastric mucosa fixed with periodate, lysine-paraformaldehyde (PLP). The increase in immunoreactivity by PLP was due to periodate itself, a component of PLP. Nitrotyrosine formed by peroxidase using NO2- and H2O2 or by peroxynitrite was not completely inhibited by 100 mM dithionite but the immunoreactivity for nitrotyrosine antibodies by PLP was completely inhibited by 5.7 mM dithionite. Although untreated eosinophils or ovalbumin (OVA) did not show protein tyrosine nitration in a standard Western blot, the treatment of the blotted membrane with PLP increased the reactivities of proteins from eosinophils with anti-nitrotyrosine antibodies. The increase in immunoreactivity of OVA with anti-nitrotyrosine antibodies by PLP did not change with pre-treatment with dithionite but was abolished by treatment with dithionite after PLP fixation. In HPLC assays, periodate did not generate nitrotyrosine from L-tyrosine and aminotyrosine. These results suggest that the treatment of eosinophils or eosinophil-containing tissues with PLP fixative augments the immunoreactivity of nitrotyrosine antibodies with eosinophils due to the formation of epitopes similar to nitrotyrosine by an oxidation reaction of periodate, which evokes an artifact in nitrotyrosine immunohistochemistry.

Topics: Artifacts; Chromatography, High Pressure Liquid; Dithionite; Eosinophils; Gastric Mucosa; Humans; Hydrogen Peroxide; Immunoenzyme Techniques; Nitrogen Compounds; Ovalbumin; Oxidants; Oxidation-Reduction; Periodic Acid; Peroxidase; Tyrosine

Although ebselen, a seleno-organic compound, inhibits inflammation in various animal models, its efficacy as an anti-asthma drug remains to be clarified. In this study, we investigated the inhibitory effect of ebselen on a guinea pig asthma model. Ebselen was orally administered at dosages of 1-20 mg/kg 2 h before an ovalbumin (OA) challenge, and then airway responses, airway inflammation, the generation of superoxide, H(2)O(2), and nitrotyrosine, and the induction of inducible nitric oxide synthase (iNOS) were evaluated. Sensitized animals challenged with OA aerosol showed dual airflow limitations, i.e., immediate and late airway responses (IAR and LAR). Ebselen significantly inhibited LAR at dosages greater than 10 mg/kg, but did not inhibit IAR at any dosage. Bronchoalveolar lavage (BAL) examination showed that airway inflammation was significantly suppressed by ebselen at 10 mg/kg. The generation of superoxide and H(2)O(2) occurred on endothelial cells of LAR bronchi, and was inhibited by 10 mg/kg of ebselen. Superoxide generation was inhibited by diphenyleneiodonium chloride (DPI), a NAD(P)H oxidase inhibitor, but not by allopurinol, a xanthine oxidase inhibitor. Immunoreactivities for iNOS and nitrotyrosine were also observed on endothelial cells of LAR bronchi and were abolished in ebselen-treated animals. The present findings suggest that ebselen can be applied as a new therapeutic agent for asthma. The possible mechanisms by which ebselen inhibits LAR likely involve suppression of oxidant formation and iNOS induction in endothelial cells.

Topics: Airway Resistance; Animals; Antineoplastic Agents, Alkylating; Antioxidants; Area Under Curve; Asthma; Azoles; Bronchitis; Bronchoalveolar Lavage Fluid; Cyclophosphamide; Disease Models, Animal; Endothelium, Vascular; Enzyme Activation; Female; Guinea Pigs; Hydrogen Peroxide; Immunoenzyme Techniques; Isoindoles; Lung; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Organoselenium Compounds; Ovalbumin; Peptide Fragments; Rabbits; Reactive Nitrogen Species; Reactive Oxygen Species; Respiratory Function Tests; Respiratory Hypersensitivity; Superoxides; Tyrosine

To explore the possible role of eosinophils in NO-mediated tissue injury, we studied a murine model of allergic asthma. Male A/J mice were sensitized and challenged intranasally with ovalbumin (OVA). Following challenge, the number of eosinophils in bronchoalveolar lavage fluid (BALF) increased from 0.4% of total cells at baseline (0.02 x 10(4) cells/ml) to 60.2% at 48 h after the challenge (9.34 x 10(4) cells/ml). The rise in eosinophil count was accompanied by a 40.3% increase in total NO(2-) plus NO(3-) (NO(x)) in BALF. This in turn was accompanied by expression of inducible NO synthase (NOS II) in airway epithelial and inflammatory cells, as well as by evidence of staining for 3-nitrotyrosine (3NT) in peribronchial inflammatory cells and at the epithelial surface. Both NO(x) production and 3NT were significantly reduced by pretreatment of the challenged mice with the highly specific NOS II inhibitor N-3-aminomethyl-benzyl-acetamidine-dihydrochloride (1400W), as well as by the nonselective NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME). L-NAME and 1400W also reduced the number of BALF eosinophils (37.2% and 61.5%, respectively, as compared with the control value), suggesting that NO production by NOS II contributes to eosinophil recruitment. To further examine the role of eosinophils, we pretreated additional mice with an anti-interleukin (IL)-5 antibody, which reduced BALF eosinophilia following OVA challenge by 90.1%. In concert with the decrease in eosinophils, the anti-IL-5 antibody reduced NO(x) in BALF almost to the baseline value, and decreased the number of 3NT-positive cells in the peribronchial region by 74.4%. Western blot analysis of protein extracted from whole lung confirmed the reduction in tyrosine nitration by anti-IL-5 antibody. These findings indicate that NO and eosinophilic inflammation are closely coupled, and suggest that eosinophils are an important source of tyrosine nitration.

Topics: Analysis of Variance; Animals; Antibodies; Asthma; Blotting, Western; Bronchoalveolar Lavage Fluid; Eosinophils; Interleukin-5; Lung; Male; Mice; Mice, Inbred Strains; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrosation; Ovalbumin; Time Factors; Tyrosine

1. The contribution of reactive nitrogen species to the development of airway hyperresponsiveness in a mouse model of allergic inflammation was investigated by the use of selective inhibitors of nitric oxide and superoxide formation. 2. Sensitized mice, repeatedly challenged with ovalbumin showed a significant (P<0.001, n=9) increase in airway responsiveness measured using whole body plethysmography. This hyperresponsiveness was accompanied by an influx of eosinophils into the airway lumen and increased levels of ovalbumin-specific serum IgE. 3. Treatment of mice with the iNOS inhibitor 1400 W or the NADPH-oxidase inhibitor apocynin did not significantly alter cellular influx into the airway lumen nor serum ovalbumin specific IgE. In contrast, apocynin as well as 1400 W inhibited ovalbumin-induced airway hyperresponsiveness (P<0.001 and P<0.05 respectively, n=9). Furthermore, the airways of allergen challenged animals showed clear 3-nitrotyrosine staining, which was mainly located in eosinophils. Remarkably, treatment with apocynin or 1400 W did not alter 3-nitrotyrosine staining. 4. These data suggest that the development of airway hyperresponsiveness during the airway inflammation upon ovalbumin challenge is dependent on the release of both superoxide and nitric oxide and is therefore likely to be dependent on reactive nitrogen species. This mechanism, however, is not reflected by 3-nitrotyrosine formation in the airways.

Topics: Acetophenones; Amidines; Animals; Antioxidants; Benzylamines; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Enzyme Inhibitors; Eosinophils; Hypersensitivity; Immunoglobulin E; Immunohistochemistry; Interferon-gamma; Interleukin-4; Interleukin-5; Lung; Male; Mice; Mice, Inbred BALB C; Neutrophils; Nitric Oxide Synthase; Ovalbumin; Specific Pathogen-Free Organisms; Tyrosine