[Involvement of urokinase and its receptor in the remodeling of normal and pathological tissue]

Urokinase is the main component of the fibrinolytic system and comprises two functions. Namely, the catalytic domain enables to trigger the proteolytic cascade in blood and in the vessel wall, stimulating the activation of growth factors, matrix remodelling and smooth muscle cell proliferation. On the other hand, the amino terminal domain of urokinase that is homologous to epidermal growth factor promotes urokinase to bind to the specific receptor. The cell surface binding of uPA may initiate the activation of the second messengers, protein phosphorylation and cell migration. This dual function of urokinase affects vascular growth, as well as the intimal thickening of the vessel wall after intravascular injury. Also uPA and its receptor are implicated in many physiological and pathological processes, including ovulation, embryogenesis, cancer metastasis, inflammation, and wound healing.