Interleukin-6 stimulates motility of vascular endothelium

Interleukin-6 (IL-6) is a cytokine which regulates host response to injury. Various preparations of recombinant human IL-6 stimulated migration of bovine brain and bovine aortic endothelial cells, with maximal responses at 100-600 ng/ml. The migration response was inhibited by anti-IL-6 monoclonal antibody. IL-6 also inhibited endothelial cell proliferation in a dose-dependent fashion. Combinations of IL-6 and tumor necrosis factor induced additive stimulation of migration. Studies with inhibitors and stimulators of various metabolic processes suggest that IL-6-induced motility: 1) does not require a pertussis toxin-sensitive G-protein, protein kinase C, or DNA synthesis; and 2) is regulated differently from the motility induced by scatter factor. A possible role for IL-6 in the regulation of physiologic angiogenesis is discussed.