ABSTRACT
BACKGROUND: Graves' disease is an autoimmune disorder characterised by excessive production of thyroid hormones, which induces increased cellular metabolism in most tissues and increased production of reactive oxygen species (ROS). The aim of this work was to analyse the effect of ROS on cell viability and the expression of catalase (CAT), glutathione peroxidase-1 (GPx-1), superoxide dismutase (SOD-1) and DNA methyltransferase-1 (DNMT-1) in peripheral blood mononuclear cells (PBMC) from patients with newly diagnosed Graves' disease or treated with methimazole. PATIENTS AND METHODS: For this study, women patients with newly diagnosed Graves' disease (n=18), treated with methimazole (n=6) and healthy subjects (n=15) were recruited. ROS were evaluated by flow cytometry, and the viability/apoptosis of PBMC was analysed by flow cytometry and fluorescence microscopy. Genomic expression of CAT, GPx-1, SOD-1 and DNMT-1 was quantified by real-time PCR. RESULTS: We found high levels of ROS and increased expression of CAT, GPx-1, SOD-1 and DNMT-1 in PBMC from patients with newly diagnosed Graves' disease. Methimazole treatment reversed these parameters. Cell viability was similar in all study groups. CONCLUSIONS: ROS induces the expression of CAT, GPx-1, and SOD-1. The activity of these enzymes may contribute to the protection of PBMC from the harmful effect of free radicals on cell viability. Increased expression of DNMT-1 may be associated with aberrant methylation patterns in immunoregulatory genes contributing to autoimmunity in Graves' disease.
Subject(s)
Graves Disease , Methimazole , DNA/metabolism , Female , Graves Disease/drug therapy , Humans , Leukocytes, Mononuclear/metabolism , Methimazole/pharmacology , Methimazole/therapeutic use , Methyltransferases/metabolism , Oxidation-Reduction , Reactive Oxygen Species/metabolism , Superoxide Dismutase/metabolismABSTRACT
Las algas pardas constituyen una fuente de alto contenido de polisacáridos como los fucoidanos que poseen importantes propiedades inmunomoduladoras. El objetivo fue determinar la viabilidad de células mononucleares de sangre periférica humana (CMSPh), producción de óxido nítrico (NO), especies reactivas de oxígeno (ROS) y de las citoquinas proinflamatorias IL-1α, IL-6, TNF-α e IFN-γ en cultivos tratados con fucoidan de Lessonia trabeculata. Se empleó fucoidan de Lessonia trabeculata proveniente de la bahía San Nicolás de Marcona-Ica. Las CMSPh se aislaron empleando Ficoll-Hypaque, se distribuyeron a una concentración de 1x105 células/pocillo en medio RPMI-1640 completo y se trataron con diferentes concentraciones de fucoidan durante 24 y 48 h. La actividad citotóxica se determinó por la reducción de MTT, la producción de NO por la reacción de Griess y las ROS por la reducción del NBT. La producción de citoquinas se cuantificó por ELISA. El fucoidan de L. trabeculata estimuló la proliferación de CMSPh y produjo el incremento de ROS a concentraciones de 100-2000 μg/mL respecto al control (p<0.001), la reacción para nitritos resultó negativa. El fucoidan incrementó la producción de IL-1α y TNF-α a concentraciones de 100 y 10 μg/mL respectivamente, mientras que la producción de IL-6 e IFN-γ no mostró diferencias significativas. Se concluye que el fucoidan de L. trabeculata estimula la proliferación de CMSPh, producción de especies reactivas de oxígeno y las citoquinas proinflamatorias IL-1α y TNF-α que poseen importantes propiedades inmunomoduladoras.
Brown algae are a source of high content of polysaccharides such as fucoidans that have important immunomodulatory properties. The aim was to determine the viability of human peripheral blood mononuclear cells (hPBMC), production of nitric oxide (NO), reactive oxygen species (ROS) and the proinflammatory cytokines IL-1α, IL-6, TNF-α and IFN -γ in cultures treated with fucoidan from Lessonia trabeculata. Fucoidan from Lessonia trabeculata from San Nicolás de Marcona-Ica Bay was used. The hPBMC were isolated using Ficoll-Hypaque, distributed at a concentration of 1x105 cells/well in complete RPMI-1640 medium and treated with different concentrations of fucoidan for 24 and 48 h. The cytotoxic activity was determined by the reduction of MTT, NO production by the Griess reaction and ROS by the reduction of NBT. The production of cytokines was quantified by ELISA. The fucoidan of L. trabeculata stimulated the proliferation of hPBMC and produced the increase of ROS at concentrations of 100-2000 μg/mL with respect to the control (p <0.001), the reaction for nitrites was negative. Fucoidan increased the production of IL-1α and TNF-α at concentrations of 100 and 10 μg/mL respectively, while the production of IL-6 and IFN-γ did not show significant differences. It is concluded that the fucoidan of L. trabeculata stimulates the proliferation of hPBMC, production of reactive oxygen species and the proinflammatory cytokines IL-1α and TNF-α that possess important immunomodulatory properties.
