Type 1 plasminogen activator inhibitor deficiency aggravates the course of experimental glomerulonephritis through overactivation of transforming growth factor beta.

Type 1 plasminogen activator inhibitor (PAI-1) is the primary inhibitor of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). Whereas PAI-1 is not expressed in normal kidneys, it is strongly induced in glomerular diseases and thus could promote the local accumulation of fibrin. To study the role of PAI-1 in the development of inflammatory glomerular injury, passive antiglomerular basement membrane (GBM) glomerulonephritis (GN) was induced in PAI-1 knockout mice and in wild-type mice of the same genetic background.