The 4G/5G PAI-1 polymorphism influences the endothelial response to IL-1 and the modulatory effect of pravastatin

Abstract

BACKGROUND: Increased plasminogen activator inhibitor (PAI-1) levels lead to impaired fibrinolytic function associated with higher cardiovascular risk. PAI-1 expression may be regulated by different inflammatory cytokines such as interleukin-1alpha (IL-1). Several polymorphisms have been described in the PAI-1 gene. AIM: We examined the influence of the 4G/5G polymorphism in the promoter region on IL-1alpha-induced PAI-1 expression by human umbilical vein endothelial cells (HUVEC) in presence or absence of pravastatin. METHODS AND RESULTS: Genotyped HUVEC were incubated with IL-1alpha (500 U mL(-1)) in presence or absence of pravastatin (1-10 microm). PAI-1 expression was analyzed by real time polymerase chain reaction (PCR), and PAI-1 antigen measured in supernatants by ELISA. IL-1alpha increased PAI-1 secretion in a genotype-dependent manner, and higher values were observed for 4G/4G compared with both 4G/5G and 5G/5G cultures (P < 0.05). Preincubation of HUVEC with 10 microm pravastatin significantly reduced IL-1-induced PAI-1 expression in 4G/4G HUVEC compared with untreated cultures (177.5% +/- 24.5% vs. 257.9% +/- 39.0%, P < 0.05). Pravastatin also attenuated the amount of secreted PAI-1 by 4G/4G HUVEC after IL-1 stimulation (5020.6 +/- 165.7 ng mL(-1) vs. 4261.1 +/- 309.8 ng mL(-1), P < 0.05). This effect was prevented by coincubation with mevalonate, indicating a dependence on HMG-CoA reductase inhibition. CONCLUSIONS: The endothelial 4G/5G PAI-1 genotype influences the PAI-1 response to IL-1alpha and the modulatory effect of pravastatin. As increased PAI-1 levels have been linked to cardiovascular disease the observed endothelial modulation by pravastatin may have potential clinical implications.