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https://hdl.handle.net/10316/12766
Title: | Diphenyleneiodonium inhibits NF-kappaB activation and iNOS expression induced by IL-1beta: involvement of reactive oxygen species | Authors: | Mendes, A. Ferreira Carvalho, A. Pato Caramona, M. Margarida Lopes, M. Celeste |
Keywords: | Reactive oxygen species; Flavonoid-containing enzymes; Diphenyleneiodonium chloride; Pro-inflammatory cytokines; Chondrocyte; Arthritis | Issue Date: | Aug-2001 | Publisher: | Taylor & Francis Ltd | Citation: | Mediators of Inflammation. 10:4 (2001) 209-215 | Abstract: | AIMS: In this work, we studied the mechanisms by which diphenyleneiodonium chloride (DPI) inhibits nitric oxide (NO) synthesis induced by the proinflammatory cytokine interleukin-1beta (IL-1) in bovine articular chondrocytes. To achieve this, we evaluated the ability of DPI to inhibit the expression and activity of the inducible isoform of the NO synthase (iNOS) induced by IL-1. We also studied the ability of DPI to prevent IL-1-induced NF-kappaB activation and reactive oxygen species (ROS) production. RESULTS: Northern and Western blot analysis, respectively, showed that DPI dose-dependently inhibited IL-1-induced iNOS mRNA and protein synthesis in primary cultures of bovine articular chondrocytes. DPI effectively inhibited NO production (IC50=0.03+/-0.004 microM), as evaluated by the method of Griess. Nuclear factor-kappa B (NF-kappaB) activation, as evaluated by electrophoretic mobility shift assay, was inhibited by DPI (1-10 microM) in a dose-dependent manner. IL-1-induced ROS production, as evaluated by measurement of dichlorofluorescein fluorescence, was inhibited by DPI at concentrations that also prevented NF-kappaB activation and iNOS expression. CONCLUSIONS: DPI inhibits IL-1-induced NO production in chondrocytes by two distinct mechanisms: (i) by inhibiting NOS activity, and (ii) by preventing iNOS expression through the blockade of NF-kappaB activation. These results also support the involvement of reactive oxygen species in IL-1-induced NF-kappaB activation and expression of NF-kappaB-dependent genes, such as iNOS | URI: | https://hdl.handle.net/10316/12766 | ISSN: | 0962-9351 | DOI: | 10.1080/09629350120080401 | Rights: | openAccess |
Appears in Collections: | FFUC- Artigos em Revistas Internacionais FCTUC Ciências da Vida - Artigos em Revistas Internacionais |
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