Vascular amine oxidases are needed for leukocyte extravasation into inflamed joints in vivo

Authors

  • Fumiko Marttila-Ichihara,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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  • David J. Smith,

    1. Biotie Therapies Corporation, Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.

  • Craig Stolen,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.

  • Gennady G. Yegutkin,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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  • Kati Elima,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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  • Nathalie Mercier,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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  • Riku Kiviranta,

    1. University of Turku, Turku, Finland
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  • Marjo Pihlavisto,

    1. Biotie Therapies Corporation, Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.

  • Sakari Alaranta,

    1. Biotie Therapies Corporation, Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.

  • Ulla Pentikäinen,

    1. University of Turku, and Åbo Akademi University, Turku, Finland
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  • Olli Pentikäinen,

    1. Åbo Akademi University, Turku, Finland
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  • Ferenc Fülöp,

    1. University of Szeged, Szeged, Hungary
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  • Sirpa Jalkanen,

    1. University of Turku, and National Public Health Institute, Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.

  • Marko Salmi

    Corresponding author
    1. University of Turku, and National Public Health Institute, Turku, Finland
    • MediCity Research Laboratory, Tykistökatu 6A, 20520 Turku, Finland
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    • Drs. Stolen, Jalkanen, and Salmi own stock in Biotie Therapies Corporation. Drs. Jalkanen and Salmi formerly held a patent on vascular adhesion protein 1. Drs. Smith, Pihlavisto, and Alaranta own stock and/or hold stock options in Biotie Therapies Corporation.


Abstract

Objective

Leukocyte traffic from the blood to the joints is crucial in the pathogenesis of arthritis. A bifunctional endothelial cell–surface glycoprotein, AOC3 (amine oxidase, copper-containing 3; also known as vascular adhesion protein 1), has both adhesive and enzymatic properties. We undertook this study to determine the contribution of AOC3 and its oxidase activity to leukocyte trafficking into inflamed joints in vivo.

Methods

We used gene-modified animals, molecular modeling, an AOC3 enzyme inhibitor, oxidase assays, and arthritis models (adjuvant-induced arthritis [AIA] in rats and anti–type II collagen antibody–induced arthritis in mice) to dissect the importance of AOC3 in vivo.

Results

The AOC3 inhibitor fitted well with a covalent binding mode into the active site of the AOC3 crystal structure. It selectively blocked the oxidase activity of AOC3 in enzyme assays. Intraperitoneal and oral administration of the AOC3 inhibitor significantly ameliorated rat AIA. In anti–type II collagen antibody–induced arthritis in mice, the AOC3 inhibitor also improved the outcome of the joint inflammation. The acute semicarbazide-sensitive amine oxidase blockade by the inhibitor had even more pronounced effects than genetic deletion of AOC3. Enzymatic analyses showed that the inhibitor also blocked 2 other structurally very closely related AOCs, but not any of more than 100 other enzymes tested.

Conclusion

These are the first data to demonstrate that the enzymatic activity of the atypical endothelial adhesion molecule AOC3, and possibly that of other closely related ecto-oxidases, is crucial for leukocyte exit from the vessels in inflamed joints in vivo.

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