2005, Number 3
Serum glycosaminoglycans from rheumatoid arthritis patients do not affect reactive oxygen species secretion by normal monocytes.
Bravo-Cuéllar A, Ramos-Remus C, Carranco-López A, Flores-Hernández G, Gómez-Contreras PC, Orbach-Arbouys S
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Language: English
References: 24
Page: 175-180
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ABSTRACT
Introduction. Several observations suggest that macrophages play an important role in the physiopathology of rheumatoid arthritis (RA). One of the most important features of RA is the serious cartilage destruction with consequent glycosaminoglycans (GAG) release. Here we studied whether GAG from RA patients can induce peripheral blood monocytes to secrete reactive oxygen species (ROS), thus being responsible for the inflammatory injury.Patients and methods. 10 female healthy postgraduate student volunteers and 10 female patients with RA were included. GAG were isolated and purifified according to Merhraban and Volpi methods. Mononuclear cells from 15 mL of peripheral blood were obtained and monocytes were identified by neutral red coloration and phagocytosis and purified by adherence to plastic. Chemiluminescence (CL) was measured on a LKB-1250 Bioluminometer at 37°C. The cuvettes contained 5 x 105 monocytes from healthy donors resuspended in Hank´s solution without phenol red at 37°C, pH 7.4. Different GAG concentrations from either normal volunteers (5, 40, 80, and 160 μg/mL) or RA patients (5 and 80 μg/mL) were resuspended in Hank´s solution in a standard volume of 100 μL. To elicit CL emission 100 μL of a solution containing 4 mg/mL of opsonized zymosan were added and photoemission was measured every ten minutes during 60 minutes.
Results. The electrophoretic patterns of serum GAG obtained from normal volunteers and RA patients were comparable: in both cases chondroitin 4 sulfate and chondroitin 6 sulfate were identified. No chemiluminescent signal was emitted by monocytes in presence of luminal and GAG, suggesting that GAG are not able to elicit respiratory burst in those cells, neither via protein C kinase Ca++ influx nor via Fc receptors. CL emission by zymosan of peripheral monocytes was higher in presence of GAG from RA patients than that in presence of GAG from normal volunteers or without GAG (increase of 36%). However, the difference was not statistically significant.
Conclusion. Serum GAG from patients are not likely to play a role in the physiopathology of RA linked to the secretion of ROS by monocytes.
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