Novel anti-inflammatory properties of the angiogenesis inhibitor vasostatin.

Endothelial cells are critically involved in the pathogenesis of inflammation, which is characterized by vasopermeability, plasma leakage, leukocyte recruitment, and neovascularization. Therefore, inhibitors of endothelial cell function could reduce inflammation. In this study, we evaluated the effects of the angiogenesis inhibitor vasostatin on inflammations induced by contact hypersensitivity reactions in mouse ears. Vasostatin-treated mice revealed significantly reduced edema formation, resulting from lower plasma leakage and inhibition of inflammation-associated vascular remodeling. Intravital microscopy studies of inflamed ears showed a decrease in the fraction of rolling leukocytes in vasostatin-treated mice, and Lycopersicon esculentum lectin-perfused ears revealed fewer leukocytes adherent to the vessel wall. The inflammatory infiltrate from vasostatin-treated mice was characterized by fewer CD8+ T cells, neutrophils, and macrophages compared to the saline-treated animals. In a modified Miles assay, vasostatin inhibited vascular endothelial growth factor-A-induced permeability, and inflamed ear tissues from vasostatin-treated mice expressed significantly reduced levels of the vascular destabilizer angiopoietin-2. These results reveal a previously unrecognized anti-inflammatory property of the angiogenesis inhibitor vasostatin, and suggest that vasostatin is a potential candidate drug for the treatment of inflammation.