8-hydroxy-2--deoxyguanosine and Behcet-Syndrome

Neutrophil extracellular traps (NETs) are upregulated and promote thrombosis in Behçet's disease (BD). However, whether NETs promote autoinflammation in BD remains unclear. This study aimed to investigate the potential role of NETs in promoting macrophage activation in BD. Firstly, we quantified NETs by measuring double-stranded DNA (dsDNA) using PicoGreen and calculating the proportion of NETosis. Then macrophages were stimulated with BD- or healthy controls (HC)-derived NETs, and IL-8 and TNF-α production and IFN-γ

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Behcet Syndrome; Extracellular Traps; Female; Histones; Humans; Interleukin-8; Macrophage Activation; Macrophages; Male; Middle Aged; Neutrophils; Reactive Oxygen Species; Tumor Necrosis Factor-alpha

Behçet's disease (BD) is a multisystemic, chronic inflammatory, relapsing disorder that is characterized by oral/genital ulcerations, ocular, arthritic, vascular, and neurologic involvements. Recent findings suggest the role of increased oxidative stress and insufficient antioxidant defence system in BD pathogenesis. It has been proposed that the increase in phagocytic cell activity by triggering oxidative reactions in various targets such as lipids, proteins, and DNA leads to severe inflammatory and degenerative pathologies seen in BD In this study, oxidant/antioxidant status of patients with BD was evaluated in comparison with controls and in respect to disease activity by measuring serum nitrite/nitrate, vitamin A, malondialdehyde (MDA), 8-hydroxy deoxyguanosine (8-OHdG), and total sulfhydryl levels (T-SH). The increase in serum MDA and 8-OHdG levels (respectively 30.04 vs. 17.93 nmol/ml, P = 0.0004 and 1.60 vs. 1.03 ng/ml, P = 0.0019) and the decrease in T-SH levels of patients with BD in comparison with controls (0.69 vs. 0.76 mmol/l, P = 0.0085) all indicate the impaired oxidant/antioxidant status in BD. The positive correlation found between MDA/8-OHdG levels (P = 0.02), and the negative correlations both between T-SH/8-OHdG levels (P = 0.031) and T-SH/MDA levels (P = 0.009) show the concordance between the parameters evaluating oxidant-antioxidant status. Among the parameters used for evaluating oxidant/antioxidant status, serum 8-OHdG was the only one showing significantly higher levels in patients with clinically active disease in comparison (P = 0.004) to patients in inactive period. Therefore, 8-OHdG that is assessed for the fist time in BD with this study can be proposed as a more reliable indicator of oxidant stress in evaluating disease activity.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Behcet Syndrome; Biomarkers; Case-Control Studies; Deoxyguanosine; DNA Damage; Female; Humans; Lipid Peroxidation; Male; Malondialdehyde; Oxidation-Reduction; Oxidative Stress; Severity of Illness Index; Vitamin A

To estimate the extent of genomic DNA damage and killing of lymphocytes by reactive oxygen intermediates in autoimmune diseases.. 8-Oxo-7-hydrodeoxyguanosine (8-oxodG), a promutagenic DNA lesion induced by reactive oxygen intermediates, was measured by high performance liquid chromatography, coupled with electrochemical detection, in hydrolysates of DNA which had been extracted from lymphocyte and polymorphonuclear leucocyte fractions of human blood. In addition, human primary blood lymphocytes stimulated by concanavalin A were assayed for cytotoxicity induced by hydrogen peroxide on day 0, by assessing cell proliferation during seven days of culture.. Constitutive 8-oxodG was detectable (mean (2 SEM) moles 8-oxodG/10(6) moles deoxyguanosine) in DNA isolated from normal human blood lymphocytes (68 (8), n = 26) and polymorphonuclear leucocytes (118 (24), n = 24). Lymphocyte DNA from donors with the following inflammatory autoimmune diseases contained significantly higher levels of 8-oxodG than that from healthy donors: rheumatoid arthritis (98 (16)), systemic lupus erythematosus (137 (28)), vasculitis (100 (32)), and Behçet's disease (92 (19)). Lymphocyte 8-oxodG levels in non-autoimmune controls and patients with scleroderma were not significantly different from those of healthy controls. The levels of 8-oxodG were significantly higher in the DNA from normal polymorphonuclear leucocytes than in paired DNA samples from normal lymphocytes, but there were no differences between levels of 8-oxodG in polymorphonuclear leucocytes from normal subjects and the patients studied. Levels of 8-oxodG did not correlate with disease duration, disease severity, or age. Lymphocytes from patients with systemic lupus erythematosus and rheumatoid arthritis, but not those with scleroderma, also showed cellular hypersensitivity to the toxic effects of hydrogen peroxide.. There was increased genomic DNA damage, and increased susceptibility to cytotoxic killing by hydrogen peroxide, in lymphocytes from patients with certain autoimmune diseases. These results might be explained by defective repair of DNA damage or by increased production of reactive oxygen intermediates in inflammation. Although more direct studies are needed, the evidence available favours the former explanation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Autoimmune Diseases; Behcet Syndrome; Cell Division; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Dose-Response Relationship, Drug; Female; Humans; Hydrogen Peroxide; Lupus Erythematosus, Systemic; Lymphocytes; Male; Middle Aged; Oxidation-Reduction; Vasculitis