瘦素在诱导血管内皮细胞纤溶酶原激活物抑制物-1表达中的作用

目的通过体外研究探讨瘦素对血管内皮细胞纤溶酶原激活物抑制物-1表达的影响。方法Ⅱ型胶原酶消化法分离和培养人脐静脉内皮细胞（HUVECs），在不同时间采用不同剂量瘦素培养HUVECs，应用荧光定量PCR、Northern blot以及Western blot检测技术研究瘦素对HUVECs PAI-1 mRNA及蛋白表达的影响。结果100ng／ml瘦素作用于内皮细胞，PAI-1 mRNA表达水平随着时间延长呈升高的趋势，8h达到最高（P〈0．001），24h后仍高于起点（P〈0．005），而tPA的表达则无显著变化（P〉0．05）。不同浓度的瘦素作用于内皮细胞，其PAI-1 mRaNA水平呈剂量依赖性升高（P〈0．001）；tPAmRNA表达亦无显著变化（P〉O．05）。100ng）ml瘦素孵育HUVECs时间依赖性促进PAI-1蛋白表达，24h达到最高峰。结论瘦素可能通过诱导血管内皮细胞PAI-1表达促进动脉粥样硬化和血栓的形成。

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.