抄録
[Objective] Protein S (PS), a vitamin K dependent anticoagulant protein functions as a cofactor for activated protein C (aPC), has recently drawn interest due to its new properties in inflammation. We examined, whether PS is able to modify cell-associated fibrinolysis and invasive potential of inflammatory cells. [Methods and Results] We analyzed tissue plasminogen activator (tPA) catalyzed activation of Glu-plasminogen in the presence of THP-1 cells, monocyte-like cells to which both plasminogen and t-PA bind. tPA catalyzed activation of Glu-plasminogen was enhanced by THP-1 cells as reported before, which was partially abolished by PS (100 nM). PS attenuated the binding of biotin-labeled plasminogen to the surface of THP-1 cells in a dose dependent manner (50-300 nM: 50% at 100 nM and 65% at 300 nM). These two phenomena were not further enhanced by aPC. PS also attenuated plasminogen-dependent invasion of THP-1 cells through matrigel in response to monocyte chemotactic protein 1, whereas it did not modify plasminogen-independent cell migration. [Conclusion] The study identifies PS as a factor to suppress plasminogen-dependent invasive potential of THP-1 cells. [Jpn J Physiol 55 Suppl:S111 (2005)]
