Plasminogen activator inhibitor type-1 protein (PAI-1)

Plasminogen activator inhibitor-1 (PAI-1) is the primary inhibitor of tissue-type and urokinase-type plasminogen activator, playing a major role in fibrinolysis.

PAI-1 is mainly produced by the endothelium, but is also secreted by other tissue types, such as adipose tissue. It is normally present at low levels in plasma and tissue, but its expression and release increased in various disease states (such as a different forms of cancer), as well as in obesity and the metabolic syndrome.

PAI-1 is also involved in the pathophysiology of renal, pulmonary, cardiovascular, and metabolic diseases. Elevated local or systemic PAI-1 can also exacerbate such pathologic conditions.