title: Enhancement of urokinase-type plasminogen activator (uPA) secretion, but not that of substrate plasminogen (PGn), by rat microglia stimulated with neuronal conditioned medium.
abstract: Assuming the presence of intercellular interactions between injured motoneurons and microglia in the axotomized facial nucleus, we investigated the effects of neuronal conditioned medium (NCM) on the release of urokinase-type plasminogen activator (uPA) from microglia. Zymography revealed that NCM markedly enhanced the release of uPA from microglia, although NCM itself did not contain a significant amount of uPA. In contrast, the secretion of plasminogen (PGn), a substrate of uPA, was not promoted by the NCM treatment. The specific effect of NCM was found to be quite distinct from that of microglial activators, interferon-gamma (IFN-gamma) or lipopolysaccharide (LPS), which reduce uPA release from microglia. In summary, Neuron-derived soluble molecules appear to stimulate microglia to enhance the production/release of uPA, but not that of PGn, by a mechanism independent of the activation reaction by IFN-gamma or LPS.
authors.affiliation: Neurobiology Laboratory, Department of Bioinformatics, Faculty of Engineering, Soka University, 4-1-1 Tangi-machi, Hachioji, Tokyo 192-8577, Japan. nakajima@t.soka.ac.jp
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakajima
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tohyama
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kurihara
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kohsaka
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D017628:Microglia / Q000378:metabolism*; D009474:Neurons / Q000737:chemistry / Q000378:metabolism*; D010958:Plasminogen / Q000378:metabolism*; D051381:Rats; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D010958:Plasminogen; D014568:Urokinase-Type Plasminogen Activator