Abstract
The pathogenesis of chronic inflammatory diseases, including rheumatoid arthritis, is regulated, at least in part, by modulation of oxidation-reduction (redox) homeostasis and the expression of redox-sensitive inflammatory genes including adhesion molecules, chemokines, and cytokines. AGIX-4207 [2-[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenoxy]acetic acid] is a novel, orally active, phenolic antioxidant and anti-inflammatory compound with antirheumatic properties. To elucidate its anti-inflammatory mechanisms, we evaluated AGIX-4207 for a variety of cellular, biochemical, and molecular properties. AGIX-4207 exhibited potent antioxidant activity toward lipid peroxides in vitro and displayed enhanced cellular uptake relative to a structurally related drug, probucol. This resulted in potent inhibition of cellular levels of reactive oxygen species in multiple cell types. AGIX-4207 selectively inhibited tumor necrosis factor (TNF)-α-inducible levels of the redox-sensitive genes, vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, with less inhibition of E-selectin, and no effect on intracellular adhesion molecule-1 expression in endothelial cells. In addition, AGIX-4207 inhibited cytokine-induced levels of monocyte chemoattractant protein-1, interleukin (IL)-6, and IL-8 from endothelial cells and human fibroblast-like synoviocytes as well as lipopolysaccharide-induced release of TNF-α, IL-1β, and IL-6 from human peripheral blood mononuclear cells. AGIX-4207 did not inhibit TNF-α-induced nuclear translocation of nuclear factor of the κ-enhancer in B cells (NF-κB), suggesting that the mechanism of action is independent of this redox-sensitive transcription factor. Taken together, these results provide a mechanistic framework for understanding the anti-inflammatory and antirheumatic activity of AGIX-4207 and provide further support for the view that inhibition of redox-sensitive inflammatory gene expression is an attractive approach for the treatment of chronic inflammatory diseases.
Footnotes
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This work was supported by AtheroGenics, Inc.
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doi:10.1124/jpet.104.080804.
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ABBREVIATIONS: VCAM-1, vascular cell adhesion molecule-1; ICAM-1, intercellular adhesion molecule-1; RA, rheumatoid arthritis; MCP-1, monocyte chemoattractant protein-1; IL, interleukin; TNF-α, tumor necrosis factor-α; ROS, reactive oxygen species; AGIX-4207, 2-[4-[[1-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]thio]-1-methylethyl]thio]-2,6-bis(1,1-dimethylethyl)phenoxy]acetic acid; HAEC, human aortic endothelial cell; HPAEC, human pulmonary artery endothelial cell; PBMC, peripheral blood mononuclear cell; DMSO, dimethyl sulfoxide; ELISA, enzyme-linked immunosorbent assay; LPS, lipopolysaccharide; FLS, fibroblast-like synoviocyte; NF-κB, nuclear factor of the κ-enhancer in B cells; PDTC, pyrrolidinedithiocarbamate; PCR, polymerase chain reaction; LMB, leukomethylene blue; 13-HpODE, 13-[S(Z,E)]-9,11-hydro-peroxyoctadecadienoic acid; PBS, phosphate-buffered saline; ISTD, internal standard; EC, endothelial cell; EMSA, electrophoretic mobility shift assay; H2DCF, 2′,7′dichlorodihydro fluorescein.
- Received November 16, 2004.
- Accepted February 1, 2005.
- The American Society for Pharmacology and Experimental Therapeutics
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