Summary Objectives: Members of the glycoprotein 130 (gp130) receptor/gp130 ligand family play a role in angiogenesis in different tissues. We tested the effect of this cytokine family on the angiopoietin (Ang)/Tie system, which is involved in blood vessel maturation, stabilization and regression. Results: Oncostatin M (OSM) increased Ang2 expression in human umbilical vein endothelial cells via JAK/STAT and MAP kinase activation. Furthermore OSM induced Ang2 expression in macrovascular endothelial cells isolated from the human aorta and in microvascular EC isolated from human heart. Our in vivo experiments revealed that mRNA expression of Ang2 in hearts of mice injected with OSM increased significantly and levels of OSM mRNA significantly correlated with mRNA levels of Ang2 in human hearts. In addition OSM increased the expression of its own receptors gp130 and OSMR in endothelial cells in vitro and in mice in vivo and levels of OSM mRNA significantly correlated with mRNA levels of gp130 and OSMR in human hearts. Conclusion: Our data, showing the effect of OSM on the angiopoietin/Tie system in endothelial cells, in hearts of mice and in human heart tissue, provide yet another link between inflammation and angiogenesis.