Angiostatin works as immune modulatory molecules via inhibition of neutrophil activation and migration

Angiostatin is derived from enzymatic degradation of plasminogen and it has endogenous anti-angiogenic properties. Although tumor cells, macrophages, platelets, and neutrophils generate high amount of angiostatin, its expression is increased in inflammatory conditions. Moreover, angiostatin binds to integrin α_vβ₃, ATP synthase, and angiomotin, which expressed on neutrophils. Activated neutrophils are essential to innate immune response, but also cause tissue damage through production of reactive oxygen species (ROS) and increase lifespan. In this article, it suggests several mechanism of angiostatin as immune regulator for neutrophils in inflammatory conditions; complex with integrin α_vβ₃ and F₁F₀ ATP synthase on lipid raft, attenuate polarization, and ROS production. These data provide possible exploit of double-edged role of neutrophils in acute inflammatory pathologies to preserve beneficial effect and minimize tissue damage.