Contribution of PAI-1 in cardiovascular pathology.

Plasminogen activator inhibitor-1 (PAI-1), is a serpin whose major function is to negate plasminogen activation and impair fibrinolysis. It occurs in plasma and tissues. Studies in genetically modified mice indicate that PAI-1 might be involved in thrombosis, vascular healing and atherosclerosis although contradictory findings have been obtained in the latter two processes. Differences between results depend on the types and the lengths of the models and underline the fact that besides its role in regulating fibrinolysis, PAI-1 plays a role in several cellular processes independent of plasminogen activation. In patients, high plasma PAI-1 levels worsen the prognosis of myocardial infarction in the acute phase and have been considered as a risk factor for coronary heart disease. The predictive capacity of PAI-1 is mainly related to several metabolic covariates which constitute the metabolic syndrome (MS). This syndrome is associated with increased cardiovascular morbidity and mortality and is becoming one of the major health problems as its prevalence is growing rapidly. Accelerated atherothrombotic process in the MS is attributed not only to metabolic abnormalities but also to a specific inflammatory state which leads to increased plasma PAI-1 levels. Modifying PAI-1 expression by PAI-1 inhibitors may open a new field of research and may reveal the true role of PAI-1 in atherosclerotic and insulin resistance processes.