Oligomerization and Nitration of the Grass Pollen Allergen Phl p 5 by Ozone, Nitrogen Dioxide, and Peroxynitrite: Reaction Products, Kinetics, and Health Effects

The allergenic and inflammatory potential of proteins can be enhanced by chemical modification upon exposure to atmospheric or physiological oxidants. The molecular mechanisms and kinetics of such modifications, however, have not yet been fully resolved. We investigated the oligomerization and nitration of the grass pollen allergen Phl p 5 by ozone (O3), nitrogen dioxide (NO2), and peroxynitrite (ONOO–). Within several hours of exposure to atmospherically relevant concentration levels of O3 and NO2, up to 50% of Phl p 5 were converted into protein oligomers, likely by formation of dityrosine cross-links. Assuming that tyrosine residues are the preferential site of nitration, up to 10% of the 12 tyrosine residues per protein monomer were nitrated. For the reaction with peroxynitrite, the largest oligomer mass fractions (up to 50%) were found for equimolar concentrations of peroxynitrite over tyrosine residues. With excess peroxynitrite, the nitration degrees increased up to 40% whereas the oligomer mass fractions decreased to 20%. Our results suggest that protein oligomerization and nitration are competing processes, which is consistent with a two-step mechanism involving a reactive oxygen intermediate (ROI), as observed for other proteins. The modified proteins can promote pro-inflammatory cellular signaling that may contribute to chronic inflammation and allergies in response to air pollution.

Coherent Acoustic Interferometry During the Photo-Driven Oxygen Evolution Reaction Associates Strain Fields with the Reactive Oxygen Intermediate

The oxygen evolution reaction (OER) from water requires the formation of meta-stable, reactive oxygen intermediates to enable oxygen-oxygen bond formation. On the other hand, such reactive intermediates could also structurally modify the catalyst. A descriptor for the overall catalytic activity, the first electron and proton transfer OER intermediate from water, (M-OH*), has been associated with significant distortions of the metal-oxygen bonds upon charge-trapping. Time-resolved spectroscopy of in-situ, photo-driven OER on transition metal oxide surfaces has characterized M-OH* for the charge trapped and the symmetry of the lattice distortions by optical and vibrational transitions, respectively, but had yet to detect an interfacial strain field arising from a surface coverage M-OH*. Here, we utilize picosecond, coherent acoustic interferometry to detect the uniaxial strain normal (100) to the SrTiO₃/aqueous interface directly caused by Ti-OH*. The spectral analysis applies a fairly general methodology for detecting a combination of the spatial extent, magnitude, and generation time of the interfacial strain through the coherent oscillations’<br>phase. For lightly n-doped SrTiO₃, we identify the strain generation time (1.31 ps), which occurs simultaneously with Ti-OH* formation, and a tensile strain of 0.06% (upper limit 0.6%). In addition to fully characterizing this intermediate across visible, mid-infrared, and now GHz-THz probes on SrTiO₃, that strain fields occur with the creation of some M-OH* modifies design strategies for tuning material properties for catalytic activity and provides insight into photo-induced degradation so prevalent for OER. To that end, the work put forth here provides a unique methodology to characterize intermediate-induced interfacial strain across OER catalysts.

Coherent Acoustic Interferometry During the Photo-Driven Oxygen Evolution Reaction Associates Strain Fields with the Reactive Oxygen Intermediate

The oxygen evolution reaction (OER) from water requires the formation of meta-stable, reactive oxygen intermediates to enable oxygen-oxygen bond formation. On the other hand, such reactive intermediates could also structurally modify the catalyst. A descriptor for the overall catalytic activity, the first electron and proton transfer OER intermediate from water, (M-OH*), has been associated with significant distortions of the metal-oxygen bonds upon charge-trapping. Time-resolved spectroscopy of in-situ, photo-driven OER on transition metal oxide surfaces has characterized M-OH* for the charge trapped and the symmetry of the lattice distortions by optical and vibrational transitions, respectively, but had yet to detect an interfacial strain field arising from a surface coverage M-OH*. Here, we utilize picosecond, coherent acoustic interferometry to detect the uniaxial strain normal (100) to the SrTiO₃/aqueous interface directly caused by Ti-OH*. The spectral analysis applies a fairly general methodology for detecting a combination of the spatial extent, magnitude, and generation time of the interfacial strain through the coherent oscillations’<br>phase. For lightly n-doped SrTiO₃, we identify the strain generation time (1.31 ps), which occurs simultaneously with Ti-OH* formation, and a tensile strain of 0.06% (upper limit 0.6%). In addition to fully characterizing this intermediate across visible, mid-infrared, and now GHz-THz probes on SrTiO₃, that strain fields occur with the creation of some M-OH* modifies design strategies for tuning material properties for catalytic activity and provides insight into photo-induced degradation so prevalent for OER. To that end, the work put forth here provides a unique methodology to characterize intermediate-induced interfacial strain across OER catalysts.

USING QUANTUM-CHEMICAL PARAMETERS FOR PREDICTING ANTI-RADICAL (НО∙) ACTIVITY OF RELATED STRUCTURES CONTAINING A CINNAMOYL FRAGMENT II. DERIVATIVES OF 2’,4’-DIHYDROXYCHALCONE, FLAVANONE AND FLAVONE, CONTAINING A HYDROXY GROUP IN POSITION 7

42 derivatives of 2’,4’-dihydroxychalcone, flavanone and flavone, containing the hydroxy group in position 7 (ring "A"), as well as substituents in the ring "B", have been studied.The aim is to study the quantum-chemical parameters of 2',4'-dihydroxychalcone, flavanone and flavone derivatives containing a hydroxy group in position 7, in order to identify the effect of substituents on Mulliken charges (a.e) in the aromatic core "A", bond numbers (Nµ), the unsaturation index (IUA) and the electron density of the carbon atoms of the cinnamoyl fragment.Materials and methods. The listed above parameters have been calculated by the semi-empirical method PM7 (WinMopac 2016 program) on the workstation with an Intel Xeon E5-1620 3.5 GHz processor, 20 GB of RAM.Results. The analysis of the values of quantum-chemical parameters, as well as their comparison with the corresponding indicators presented in Report I, revealed a number of important features associated with the influence of the hydroxy group in position 7 (ring "A") on the studied quantum-chemical parameters of molecules. It has been established that the hydroxy group in the ring “A” does not significantly affect the Mulliken charge and the electron density of the carbon atoms of the propenone unit C-7→C-8→C-9. On atom C-9 (carbonyl carbon), the Mulliken charge always has a positive value, and the electron density is about 3.4670-3.4840 for all three groups of compounds. The transition from 2’,4’-dihydroxychalcone to flavanone and flavone by the formation of the pyrone heterocycle, is accompanied by an increase in the negative charge on C-8, which can be explained by the involvement of the oxygen heteroatom in the transmission of electronic effects. The hydroxy group in the ring “A”, has practically no effect on the charge and electron density of atoms. An analysis of the values of bond numbers and unsaturation indices suggests that atoms C-1 of 2’,4’-dihydroxychalcone and 7-hydroxyflavanone derivatives, are characterized by the lowest Nµ value; the lowest bond numbers are characteristic for atom C-8 derivatives of 7-hydroxyflavone. Consequently, the primary attack of the HO·radical will be directed at C-1 (in chalcones and flavanones) and at C-8 in flavones.Conclusion. The performed quantum-chemical calculations make it possible to analyze the effect on the main quantum-chemical parameters of the molecule, which can be useful in predicting the biological activity of flavanoid compounds due to their antiradical effect on reactive oxygen intermediate species (ROIs).

Zingiber cassumunar Roxb. extract increase the reactive oxidant level and interleukins expression in vitro

Zingiber cassumunar Roxb. (bangle) has a variety of active compounds, including curcumin and phenylbutenoid. Bangle rhizoma reported exhibiting immunomodulatory activities. This research aims to determine the mechanism of bangle extract as an immunomodulator by the secretion of Reactive Oxygen Intermediate (ROI), Nitric Oxide (NO), and interleukin (IL-10 and IL-14) expression level. Bangle extract (Zingiber cassumunar Roxb.) was made by the maceration method using 96% ethanol solvent. This research was administered in vitro using macrophage cells from male mice with Balb/C strain divided into 2 groups: normal control and treatment group (receiving 25, 50, and 100 ppm of extract). The administration of bangle extract can function as an immunomodulator by an increase of ROI in 25 and 50 ppm of the extract significantly than the control group (p <0.05), the treatment groups decrease NO level (p <0.05), it also was found to increase expression of IL-10 and IL-14 expression levels (p <0.05). Zingiber cassumunar Roxb. extract was potentially to be developed as an immunomodulator.

AB0572 REDUCED ENZYMATIC ACTIVITY OF ANTIOXIDANT SYSTEM IN SCLEROSIS.

Background:The antioxidant system is a natural barrier to the pathologic effect of reactive oxygen intermediate (ROI) on the tissues of patients with systemic scleroderma (SSD). It is comprised of enzymatic links, of which the cascade of enzymes like superoxide dismutase (SOD), glutathione peroxidase (GP), glutathione reductase (GR) and others are most important. Autoantibodies to enzymes of the antioxidant system can bring about a reduction in their biochemical activity.Objectives:Studying the effect of production of antibodies to antioxidant system enzymes SOD, GP and GR in patients with SSD using immobilized magnetocontrolable adsorbents.Methods:We observed 40 patients with SSD and 30 apparently healthy individuals. Degree I of activity was established in 15 patients (37,5%), degree II – in 24 patients (60%), degree III – in 1 patient (2,5%). Patients with subacute and acute course of the disease, degree of activity II and III were united in one group due to their small number. Antibodies to SOD, GR and GP were determined in blood serum of patients upon admission and discharge using immobilized antigen forms of enzymes (Gontar I.P., 2001). Commercial preparations served as antigens when determining antibodies to SOD, GR and GP.Results:A study of blood sera from healthy individuals showed SOD antibodies level of 0,06±0,004, GP antibodies – 0,045±0,003, GR antibodies – 0,05±0,01. The total activity of SOD in the group of healthy people was 38,2±1,2 IU; GP – 0,153±0,007, GR – 114,3±3,7. Upon admission to hospital patients showed a reliably reduced activity of SOD and GR (p<0,002), and unreliably reduced activity of GP (р<0,02). Among patients with SSD antibodies to SOD were detected in 15 people (37,5%), antibodies to GP – in 14 (35%), antibodies to GR – in 16 (40%). With degree I of activity, high levels of SOD antibodies were detected in 4 patients (26,7%), antibodies to GP – in 4 patients (20%), to GR – in 6 (40%). When SSD was degree of activity II and III, the patients showed a reduced activity of SOD, GR and GP (р<0,05) compared with healthy people, and higher antibody levels (р<0,002). We noted an increase in the number of patients whose serum showed high antibody levels: antibodies to SOD in 11 people (44%), to GP – in 11 (44%), antibodies to GR – in 12 (48%). In the group of SSD patients who showed high levels of SOD, GR and GP antibodies, we observed a reliable reduction in enzymatic activity (р<0,05). SOD activity was reliably reduced both in chronic and subacute course of the disease (р<0,02). In the group of patients with high levels of enzyme antibodies we noted a reliable reduction in enzymatic activity. A test for antibodies to SOD, GR and GP in SSD patients with involvement of various organs and systems showed their reliably elevated level in all clinical groups (р=0,032, р=0,034 and р=0,025).Conclusion:Production of antibodies to antioxidant system enzymes plays an important role in pathogenesis of SSD involving internal organs and tissues and aggravating the course of the disease on the whole.Disclosure of Interests:None declared

AB1074 FEATURES OF COMBINED USE OF BIOMARKERS AND VISUALIZATION METHODS FOR DIAGNOSIS OF HEART DAMAGE IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:In rheumatoid arthritis (RA), the endocardium is involved in the inflammatory process, which is caused by immunopathogenetic mechanisms involving CD4 +, T-cells and proinflammatory macrophages. Minor changes in the cardiovascular system can be successfully detected by ultrasound in patients with RA.Objectives:to improve the quality of non-invasive diagnostics of heart disease in patients with RA.Methods:57 patients with RA were under observation: 7 men and 50 women aged from 26 to 70 years; mean age 50.45 ± 10.12 years; activity (according to DAS28) was low for 3.5%, medium for 86%, and high for 10.5%. Immunological examination included determination of serum IgM-RF, CRP, antibodies to cyclic citrulline peptide (anti-CCP), antibodies to modified vimentin (anti-MCV), antibodies to antigen RA33, levels of angiopoietin-like proteins 3 (ANGPTL3) and 4 (ANGPTL4) types (classical ELISA test), as well as the detection of IgG antibodies to 5’-nucleotidase (5’-NT) and xanthine oxidase (XO) (modified ELISA test). Data from ultrasound, magnetic resonance (MRT) and computer (CT) tomography were used in assessing the state of the heart structures.Results:The pathology of cardiovascular system was diagnosed in 28 (49.1%) patients with RA. Signs of the heart damage were noted in 33.3% of cases (pericarditis and valvular heart disease were most often detected). In groups of patients with RA with elevated levels of antibodies to 5’-NT and XO (compared with RA patients with normal parameters), there was a significantly more frequent heart damage (for antibodies to 5’-NT: χ2= 3.8, p = 0.047; for antibodies to XO: χ2= 3.92, p = 0.041). It was discovered that in all patients with an increased level of antibodies to XO, one of the lesions of the heart valvular apparatus of varying severity was noted. According to ultrasound data (usually confirmed by CT and / or MRT), signs of valvular dysfunction were found in 21 (36.8%) patients with RA. The high frequency of mitral prolapse (28.6%) may be associated with the presence of a chronic inflammatory process that is able to accelerate the development of atherosclerosis and heart disease in RA patients. A tendency to an increase in the prevalence of mitral prolapse in patients with a longer duration of the disease (p = 0.062) and with high levels of serum ANGPTL4 (p = 0.058) was found.One of the main factors leading to the development of vascular pathology in RA is the accumulation of reactive oxygen intermediate. Antibodies to XO can affect the biochemical activity of the enzyme in the serum of patients with RA, stimulating the increased formation of O-form XO, which has a pronounced prooxidant effect (especially to lipids). ANGPTL4, acting as a potent inhibitor of endothelial lipoprotein lipase, can suppress the release of non-esterified fatty acids and their transfer to the heart muscle.Conclusion:To identify subclinical signs of involvement of cardiovascular system in the pathological process in the early asymptomatic stages of RA, it is advisable to use imaging techniques in combination with immunological markers of heart damage, which can be especially useful for screening, diagnostic evaluation and determining cardiovascular risk.Disclosure of Interests:None declared