Roles of Leptin in the induction of PAI-1 expression in vascular endothelial cell

Objective To investigate in vitro the effect of human leptin on the expression of plasminogen activator inhibitor type 1 (PAI-1) in vascular endothelial cells (VEC). Methods Human umbilical vein endothelial cells (HUVECs) were isolated and subcultured by enzymatic disaggregation in the presence of human recombinant leptin at different times. Real-time PCR, Northern blot and Western blot were used to detect mRNA and protein expression of PAI-1. Results Under the condition of 100 ng/ml leptin, the expression levels of PAI-1 mRNA increased as the time increased in general, and reach the peak at 8 h point. The levels of tPA showed no significant changes as the time increased. The levels of PAI-1 mRNA increased as the concentration of leptin increased, while those of tPA mRNA showed no significant difference. Human leptin induced the expression of PAI-1 mRNA and protein in HUVECs in time-and dose-dependent manner. Conclusion Human leptin upregulated PAI-1 expression. Thus, chronic oxidative stress in endothelial cells under hyperleptinemia may activate artherothrombosis processes and contribute to the development of vascular pathology.