N-Acetylglucosamine Prevents IL-1β-Mediated Activation of Human Chondrocytes

Alexander R. Shikhman, Klaus Kuhn, Nada Alaaeddine and Martin Lotz
J Immunol April 15, 2001, 166 (8) 5155-5160; DOI: https://doi.org/10.4049/jimmunol.166.8.5155

Article Figures & Data

Figures

  • FIGURE 1.
    FIGURE 1.

    Effect of GlcN and GlcNAc on IL-1β-induced NO production in cultured human articular chondrocytes. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcN or GlcNAc (10 mM) for 24 h. NO production was measured in culture supernatants by the Griess reaction. This figure represents mean ± SEM of the data obtained from seven independent experiments using seven different chondrocyte donors. CTRL, control.

  • FIGURE 2.
    FIGURE 2.

    Dose response of IL-1β-mediated NO production to GlcN and GlcNAc in human articular chondrocytes. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with various concentrations of GlcN or GlcNAc for 24 h. NO production was measured in culture supernatants by the Griess reaction.

  • FIGURE 3.
    FIGURE 3.

    Effect of selected monosaccharides on IL-1β-induced NO production in human articular chondrocytes. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with selected monosaccharides at a concentration of 10 mM for 24 h. NO production was measured in culture supernatants by the Griess reaction. This figure represents mean ± SEM of the data obtained from five independent experiments using five different chondrocyte donors. CTRL, Control; Glc, glucose; GlucurAc, glucuronic acid; MannAc, N-acetylmannosamine. The differences between GlcNAc + IL-1 vs IL-1, GalNAc + IL-1 vs IL-1, and GlcN + IL-1 vs IL-1 were statistically significant with p <0.01, 0.01, and 0.02, respectively.

  • FIGURE 4.
    FIGURE 4.

    Effect of GlcNAc and its oligomers on IL-1β-induced NO production in cultured human articular chondrocytes. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with selected GlcNAc oligomers at a concentration of 10 mM for 24 h. Production of NO was measured in culture supernatants by the Griess reaction. This figure represents mean ± SEM of the data obtained from three independent experiments using three different chondrocyte donors. The difference between GlcNAc + IL-1 vs IL-1 groups was statistically significant, p < 0.02. The differences between (GlcNAc)2 + IL-1 vs IL-1 and (GlcNAc)3 + IL-1 vs IL-1 were not statistically significant. CTRL, Control.

  • FIGURE 5.
    FIGURE 5.

    Effect of GlcNAc on IL-1β-induced iNOS and COX-2 mRNA expression. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Expression of iNOS and COX-2 mRNA was measured by Northern blotting. CTRL, Control.

  • FIGURE 6.
    FIGURE 6.

    Effect of GlcNAc on IL-1β-induced iNOS protein expression. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Expression of iNOS was measured by Western immunoblot using anti-iNOS (C-19; Santa Cruz Biotechnology) Abs. CTRL, Control.

  • FIGURE 7.
    FIGURE 7.

    Effect of GlcNAc on IL-1β-induced COX-2 (A) and COX-1 (B) protein expression. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Expression of COX-2 and COX-1 was analyzed in Western immunoblot. CTRL, Control.

  • FIGURE 8.
    FIGURE 8.

    Effect of GlcNAc on IL-1β-induced IL-6 production in cultured human articular chondrocytes. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Production of IL-6 was measured in culture supernatants by ELISA. This figure represents mean ± SEM of the data obtained from three independent experiments using three different chondrocyte donors. CTRL, Control.

  • FIGURE 9.
    FIGURE 9.

    GlcNAc does not inhibit IL-1β-induced MAP kinase activation. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Activation of ERK (A), JNK (B), and p38 MAP (C) kinases was measured by Western immunoblot. CTRL, Control.

  • FIGURE 10.
    FIGURE 10.

    Effect of GlcNAc on IL-1β-induced nuclear translocation of NF-κB. Human articular chondrocytes were stimulated with IL-1β (5 ng/ml) and incubated with GlcNAc (10 mM) for 24 h. Nuclear translocation of NF-κB was analyzed by EMSA. sp. comp., Competition with unlabeled NK-κB oligonucleotide; unsp. comp., competition with unlabeled Oct-1 oligonucleotide.

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