Urokinase Localization and Activity in Isolated Eosinophils

• Published in: Thrombosis research 1997-11, Vol.88 (4), p.373-379
• Main Authors: Mabilat-Pragnon, C, Janin, A, Michel, L, Thomaïdis, A, Legrand, Y, Soria, C, Lu, H
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological Transport, Active - drug effects; Cell Membrane - enzymology; Cell Movement - drug effects; Cell Movement - physiology; Cell physiology; Cytoplasmic Granules - enzymology; Eosinophils; Eosinophils - drug effects; Eosinophils - enzymology; Eosinophils - ultrastructure; Fundamental and applied biological sciences. Psychology; Granulocytes; Humans; Immunohistochemistry; In Vitro Techniques; Microscopy, Immunoelectron; Molecular and cellular biology; Motility and taxis; Neutrophils - enzymology; Platelet Activating Factor - pharmacology; Receptors, Cell Surface - metabolism; Receptors, Urokinase Plasminogen Activator; Urokinase-type plasminogen activator; Urokinase-Type Plasminogen Activator - metabolism
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/S0049-3848(97)00268-5

Urokinase-type plasminogen activator is implicated in cell invasion and migration. In this study, we provide evidence for the presence of urokinase-type plasminogen activator (3.5±1.5 ng/mg of cell protein) in isolated peripheral blood eosinophils, in comparison to 6.7±2.3 ng/mg of protein in neutrophils. Both immunocytochemical and immunogold staining of urokinase-type plasminogen activator on electron microscopy showed its localization in granules of resting cells. Mild stimulation by platelet-activating factor induced a translocation of urokinase-type plasminogen activator from the granules to the cell membrane and a formation of urokinase-type plasminogen activator capping, suggesting a role for urokinase-type plasminogen activator in eosinophil migration. The activation of eosinophils led to the release of factor(s) which, after activation of pro-urokinase-type plasminogen activator, induced an inactivation of generated urokinase-type plasminogen activator. Our results suggest that urokinase-type plasminogen activator is implicated in activated eosinophils invasiveness because the exposure of urokinase-type plasminogen activator is regulated both in space and time.