Abrogation of antibody-induced arthritis in mice by a self-activating viridin prodrug and association with impaired neutrophil and endothelial cell function

Authors

  • Lars Stangenberg,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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  • Chris Ellson,

    1. Massachusetts Institute of Technology, Cambridge
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  • Virna Cortez-Retamozo,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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  • Adriana Ortiz-Lopez,

    1. Harvard Medical School, Boston, and Broad Institute of Harvard and MIT, Cambridge, Massachusetts
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  • Hushan Yuan,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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  • Joseph Blois,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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  • Ralph A. Smith,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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  • Michael B. Yaffe,

    1. Massachusetts Institute of Technology, Cambridge
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  • Ralph Weissleder,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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    • Dr. Weissleder owns stock in VisEn Medical and has served as a paid consultant with investment analysts on behalf of T2 Biosystems.

    • Drs. Weissleder, Josephson, and Mahmood (along with other Massachusetts General Hospital [MGH] employees) are coinventors on a patent owned by MGH for intramolecularly quenched near-infrared fluorescent probes; VisEn Medical has licensed the patent, and the authors therefore receive (minimal) royalties.

  • Christophe Benoist,

    1. Harvard Medical School, Boston, and Broad Institute of Harvard and MIT, Cambridge, Massachusetts
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  • Diane Mathis,

    1. Harvard Medical School, Boston, and Broad Institute of Harvard and MIT, Cambridge, Massachusetts
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  • Lee Josephson,

    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
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    • Drs. Weissleder, Josephson, and Mahmood (along with other Massachusetts General Hospital [MGH] employees) are coinventors on a patent owned by MGH for intramolecularly quenched near-infrared fluorescent probes; VisEn Medical has licensed the patent, and the authors therefore receive (minimal) royalties.

  • Umar Mahmood

    Corresponding author
    1. Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts
    • Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, White 427, Boston, MA 02114
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    • Drs. Weissleder, Josephson, and Mahmood (along with other Massachusetts General Hospital [MGH] employees) are coinventors on a patent owned by MGH for intramolecularly quenched near-infrared fluorescent probes; VisEn Medical has licensed the patent, and the authors therefore receive (minimal) royalties.

    • Dr. Mahmood has received consulting fees from VisEn Medical (less than $10,000).


Abstract

Objective

To test a novel self-activating viridin (SAV) prodrug that slowly releases wortmannin, a potent phosphoinositide 3-kinase inhibitor, in a model of antibody-mediated inflammatory arthritis.

Methods

The SAV prodrug was administered to K/BxN mice or to C57BL/6 (B6) mice that had been injected with K/BxN serum. Ankle thickness was measured, and histologic changes were scored after a 10-day disease course (serum-transfer arthritis). Protease activity was measured by a near-infrared imaging approach using a cleavable cathepsin–selective probe. Further near-infrared imaging techniques were used to analyze early changes in vascular permeability after serum injection, as well as neutrophil–endothelial cell interactions. Neutrophil functions were assessed using an oxidative burst assay as well as a degranulation assay.

Results

SAV prevented ankle swelling in mice with serum-transfer arthritis in a dose-dependent manner. It also markedly reduced the extent of other features of arthritis, such as protease activity and histology scores for inflammation and joint erosion. Moreover, SAV was an effective therapeutic agent. The underlying mechanisms for the antiinflammatory activity were manifold. Endothelial permeability after serum injection was reduced, as was firm neutrophil attachment to endothelial cells. Endothelial cell activation by tumor necrosis factor α was impeded by SAV, as measured by the expression of vascular cell adhesion molecule. Crucial neutrophil functions, such as generation of reactive oxygen species and degranulation of protease-laden vesicles, were decreased by SAV administration.

Conclusion

A novel SAV prodrug proved strongly antiinflammatory in a murine model of antibody-induced inflammatory arthritis. Its activity could be attributed, at least in part, to the inhibition of neutrophil and endothelial cell functions.

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