107 research outputs found

    Taurine bromamine (TauBr) - its role in immunity and new perspectives for clinical use

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    This review is an attempt to summarize our knowledge about taurine bromamine (TauBr) properties, its role in innate immunity and its therapeutic potential

    Collagen type II modification by hypochlorite

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    Oxidation of proteins is a common phenomenon in the inflammatory process mediated by highly reactive agents such as hypochlorite (HOCl/OCl-) produced by activated neutrophils. For instance, in rheumatoid arthritis hypochlorite plays an important role in joint destruction. One of the major targets for HOCl/OCl- is collagen type II (CII) - the primary cartilage protein. In our study, HOCl/OCl- mediated collagen II modifications were tested using various methods: circular dichroism (CD), HPLC, ELISA, dynamic light scattering (DLS), fluorimetry and spectrophotometry. It was shown that hypochlorite action causes deamination with consecutive carbonyl group formation and transformation of tyrosine residues to dichlorotyrosine. Moreover, it was shown that ammonium chloramine (NH2Cl) formed in the reaction mixture reacts with CII. However, in this case the yield of carbonyl groups and dichlorotyrosine is lower than that observed for HOCl/OCl- by 50%. CD data revealed that collagen II exists as a random coil in the samples and that chlorination is followed by CII fragmentation. In the range of low HOCl/OCl- concentrations (up to 1 mM) 10-90 kDa peptides are predominant whereas massive production of shorter peptides was observed for high (5 mM) hypochlorite concentration. DLS measurements showed that chlorination with HOCl/OCl- decreases the radius of collagen II aggregates from 30 to 6.8 nm. Taking into account the fact that chlorinated collagen is partially degraded, the DLS results suggest that smaller micelles are formed of the 10-90 kDa peptide fraction. Moreover, collagen chlorination results in epitope modification which affects CII recognition by anti-CII antibodies. Finally, since in the synovial fluid the plausible hypochlorite concentration is smaller than that used in the model the change of size of molecular aggregates seems to be the best marker of hypochlorite-mediated collagen oxidation

    Air particulate matter SRM 1648a primes macrophages to hyperinflammatory response after LPS stimulation

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    Objective Exposure to air particulate matter (PM) is associated with chronic inflammatory and autoimmune diseases. Macrophages are responsible for the regulation of chronic inflammation. However, whether PM affects macrophage polarization remains unclear. The aim of this study was to evaluate whether nontoxic concentrations of urban PM are able to prime macrophages to altered inflammatory response upon LPS challenge. Methods We used two forms of the urban particulate matter SRM 1648a, intact PM and PM deprived of organic compounds (PMΔ\DeltaC). Peritoneal murine macrophages were exposed to different concentrations of PM for 24 h and then challenged with LPS. Production of inflammatory mediators by macrophages was measured to test immunostimulatory/priming capacity of PM. Results Particulate matter used at non-cytotoxic concentrations induced a dose-dependent production of proinflammatory cytokines (TNFαTNF-\alpha, IL-6, IL-12p40). By contrast, PMΔ\Delta C were not able to stimulate macrophages. However, macrophages primed with both forms of PM show proinflammatory response upon LPS challenge. Conclusions Our data indicate that exposure of macrophages to low concentrations of PM may prime the cells to hyperinflammatory response upon contact with LPS. Further studies are necessary to explain whether the exposure of patients suffering from chronic inflammatory diseases to particulate matter is responsible for the exacerbation of clinical symptoms during bacterial infections
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