Monosodium urate crystals induce oxidative stress in human synoviocytes.
Arthritis Res Ther
; 18(1): 117, 2016 05 21.
Article
em En
| MEDLINE
| ID: mdl-27209322
BACKGROUND: Gout is the most common inflammatory arthropathy of metabolic origin and it is characterized by intense inflammation, the underlying mechanisms of which are unknown. The aim of this study was to evaluate the oxidative stress in human fibroblast-like synoviocytes (FLS) exposed to monosodium urate (MSU) crystals, which trigger an inflammatory process. METHODS: Human FLS isolated from synovial tissue explants were stimulated with MSU crystals (75 µg/mL) for 24 h. Cellular viability was evaluated by crystal violet staining, apoptosis was assessed using Annexin V, and the cellular content of reactive oxygen species (ROS) and nitrogen species (RNS) (O2 (-), H2O2, NO) was assessed with image-based cytometry and fluorometric methods. In order to determine protein oxidation levels, protein carbonyls were detected through oxyblot analysis, and cell ultrastructural changes were assessed by transmission electron microscopy. RESULTS: The viability of FLS exposed to MSU crystals decreased by 30 % (P < 0.05), while apoptosis increased by 42 % (P = 0.01). FLS stimulated with MSU crystals exhibited a 2.1-fold increase in H2O2 content and a 1.5-fold increase in O2 (-) and NO levels. Oxyblots revealed that the spots obtained from FLS protein lysates exposed to MSU crystals exhibited protein carbonyl immunoreactivity, which reflects the presence of oxidatively modified proteins. Concomitantly, MSU crystals triggered the induction of changes in the morphostructure of FLS, such as the thickening and discontinuity of the endoplasmic reticulum, and the formation of vacuoles and misfolded glycoproteins. CONCLUSIONS: Our results prove that MSU crystals induce the release of ROS and RNS in FLS, subsequently oxidizing proteins and altering the cellular oxidative state of the endoplasmic reticulum, which results in FLS apoptosis.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ácido Úrico
/
Estresse Oxidativo
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Fibroblastos
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Sinoviócitos
Limite:
Humans
Idioma:
En
Revista:
Arthritis Res Ther
Assunto da revista:
REUMATOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Reino Unido