Suppression of LPS-induced NF-κB activity in macrophages by the synthetic aurone, (Z)-2-((5-(hydroxymethyl) furan-2-yl) methylene) benzofuran-3(2H)-one

• Published in: International immunopharmacology 2017-02, Vol.43, p.116-128
• Main Authors: Park, Hyo S., Nelson, David E., Taylor, Zachary E., Hayes, James B., Cunningham, Kirsten D., Arivett, Brock A., Ghosh, Rajarshi, Wolf, Larissa C., Taylor, Kimberley M., Farone, Mary B., Handy, Scott T., Farone, Anthony L
• Format: Article
• Language: English
• Subjects: Allergic reactions; Animals; Anti-inflammatory; Anti-Inflammatory Agents - therapeutic use; Aquatic plants; Aurone; Autoimmune diseases; Benzofuran; Benzofurans - chemical synthesis; Benzofurans - pharmacology; Biotechnology; Cytokines; Cytokines - metabolism; Degradation; Derivatives; Gene expression; Genes; Humans; Hypersensitivity; IKK-β; Inflammation - drug therapy; Inflammation Mediators - metabolism; iNOS; Interleukin 8; Intracellular signalling; JNK protein; Lipopolysaccharides; Lipopolysaccharides - immunology; Macrophage; Macrophages; Macrophages - drug effects; Macrophages - immunology; MAP kinase; Methylene; Mice; Monocytes; Monocytes - drug effects; Monocytes - immunology; NF-kappa B - metabolism; NF-κB; Nitric Oxide Synthase Type II - genetics; Nitric Oxide Synthase Type II - metabolism; Nitric-oxide synthase; Nuclear reactions; Nuclear transport; Pharmacology; Phosphorylation; Polarization; Polymerase chain reaction; RAW 264.7 Cells; Side effects; Signal Transduction - drug effects; Stroke; Transcription factors; Translocation; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Tumor necrosis factor-TNF
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2016.12.004

Suppressing cytokine responses has frequently been shown to have promising therapeutic effects for many chronic inflammatory and autoimmune diseases. However, the severe side effects associated with the long-term use of current treatments, such as allergic reactions and increased risk of stroke, have focused attention towards the targeting of intracellular signaling mechanisms, such as NF-κB, that regulate inflammation. We synthesized a series of non-natural aurone derivatives and investigated their ability to suppress pro-inflammatory signaling in human monocyte (THP-1) and murine macrophage-like (RAW 267.4) cell lines. One of these derivatives, (Z)-2-((5-(hydroxymethyl) furan-2-yl) methylene) benzofuran-3(2H)-one (aurone 1), was found to inhibit LPS-induced secretion of the pro-inflammatory cytokines, tumor-necrosis factor α (TNFα), interleukin 1β (IL-1β), and IL-8 by THP-1 cells. To investigate the mechanism, we probed the effect of aurone 1 on LPS-induced MAPK and NF-κB signaling in both THP-1 and RAW264.7. While aurone 1 pre-treatment had no effect on the phosphorylation of ERK, JNK, or p38 MAPK, it strongly suppressed activation of IKK-β, as indicated by attenuation of Ser176/180 phosphorylation, resulting in decreased phosphorylation of p65 (ser536) as well as phosphorylation (ser32) and degradation of IκBα. Consistent with this, aurone 1 significantly reduced LPS-stimulated nuclear translocation of p65-containing NF-κB transcription factors and expression of an mCherry reporter of TNFα gene transactivation in RAW264.7 cells. Inhibition of TNFα expression at the transcription level was also demonstrated in THP-1 by qRT-PCR. In addition to its effects on cytokine expression, aurone 1 pre-treatment decreased expression of iNOS, a bona fide NF-κB target gene and marker of macrophage M1 polarization, resulting in decreased NO production in RAW264.7 cells. Together, these data indicate that aurone 1 may have the potential to function as a pharmacological agent for the treatment of chronic inflammation disorders. [Display omitted] •Aurone 1 inhibits TNFα, IL-1β, and IL-8 expression in LPS-stimulated THP-1 cells.•p65 translocation and NF-κB-dependent transcription is blocked by aurone 1 in macrophages.•The mechanism involves inhibition of IKKβ phosphorylation and IκBα degradation.•Aurone 1 has no significant effect on LPS-induced MAPK phosphorylation.•Aurone 1 suppresses iNOS expression and NO production in RAW264.7 macrophages.