Serine protease inhibitor clade E member 1 (PAI-1)

Serine protease inhibitor clade E member 1, commonly known as Plasminogen Activator Inhibitor-1 (PAI-1), is the primary physiological inhibitor of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) [1, 6]. By inhibiting these activators, PAI-1 prevents the conversion of plasminogen to plasmin, thereby serving as a critical negative regulator of the fibrinolytic system and extracellular matrix (ECM) degradation [3, 15]. Beyond its role in hemostasis, PAI-1 is involved in diverse biological processes including cell migration, angiogenesis, and the regulation of cellular senescence [4, 11]. Elevated levels of PAI-1 are strongly associated with a prothrombotic state and are implicated in the pathogenesis of cardiovascular diseases, tissue fibrosis, metabolic syndrome, and cancer progression [3, 10]. Consequently, PAI-1 has emerged as a significant therapeutic target, with various small-molecule inhibitors and antibodies being developed to restore fibrinolytic balance and mitigate fibrotic or age-related pathologies [2, 6, 15].

Other names

Plasminogen activator inhibitor 1PAI-1PAI1PLANH1Serpin E1Endothelial plasminogen activator inhibitor

Inhibition of PAI-1 activity to promote fibrinolysis and reduce extracellular matrix accumulation or cellular senescence.