Plasminogen activation in degradation and penetration of extracellular matrices and basement membranes by invasive bacteria

Methods to assess in vitro the role of plasminogen activation in enterobact erial degradation of extracellular matrices and their protein components as well as in penetration through basement membrane ave described. Developmen t of these methods was initiated after the findings that enterobacterial su rface structures (fimbriae and the Pla surface protease) function in plasmi nogen activation as Well as in laminin-and/or fibronectin-specific adhesion . Enterobacteria with these properties degrade radiolabeled laminin as well as metabolically labeled extracellular matrix from cultured endothelial or epithelial cells. Plasmin-coated bacteria also penetrate through the recon stituted basement membrane preparation Matrigel. The processes are dependen t on plasminogen activation by the invasive bacteria. The results suggest a pathogenic similarity between enterobacteria and tumor cells in cellular m etastasis through tissue barriers. (C) 2000 Academic Press.