海带多糖对血管内皮细胞保护作用

Effects of polysaccharide of laminaria on expression and secretion of t-PA and PAI-1

目的利用人脐静脉内皮细胞(HUVEC)体外培养模型,探讨海带多糖L01对肾上腺素刺激状态下表达和分泌的组织型纤溶酶原激活物(t-PA)及其抑制剂(PAI-1)的影响。方法体外培养人脐静脉内皮细胞系(ECV-304),随机分成6组:空白对照组,模型组,海带多糖对照组,海带多糖L01低、中、高剂量组。培养后24,48,72h采样,酶联免疫吸附法测定HUVEC培养上清液中的t-PA和PAI-1含量。RT-PCR检测t-PA和PAI-1mRNA的表达,其扩增产物经电泳后密度扫描及半定量分析。结果海带多糖L01各浓度组能拮抗肾上腺素的刺激作用,给药24,48h后t-PA抗原分泌明显降低,但对t-PAmRNA表达无明显影响;培养液中PAI-1含量给药48,72h后明显降低,PAI-1mRNA表达明显下调,并具有一定的量效关系。结论海带多糖对血管内皮具有一定保护作用,使内皮细胞表面纤溶活性增高,为其发挥抗血栓作用的机制之一。

Objective To study the effects of polysaccharide from laminaria（L01）on the expression and secretion of tissue plasminogen activator（t-PA）and plasminogen activator inhibitor-1（PAI-1）stimulated by adrenaline in cultured human umbilical vein endothelial cell（HUVEC）.Methods With added adrenaline,six groups of human umbilical vein endothelial cell：line ECV-304 was exposed to different concentrations of polysaccharide of laminaria and cultured for 24,48 and 72 hours respectively in vitro.The levels of t-PA and PAI-1 in cultured supernatants were measured by enzyme-linked immunosorbent assay：RT-PCR was used to detect the expression of t-PA and PAI-1 messenger RNA（mRNA）in HUVEC,and the related products were examined by density scan and half-quantiative analysis after electrophoresis to reflect the variety of transcripition levels.Results Stimulated by adrenaline,the levels of t-PA and PAI-1 in cultured supernatants increased significantly.But the effect was reduced by different concentrations of L01 after cultured for 24,48 hours,the levels of t-PA decreased siginificantly,but the levels of expression of t-PA mRNA were not siginificantly different all the time.After cultured 48,72h,the level of PAI-1 decreased siginificantly,and the levels of expression of PAI-1 mRNA decreased siginificantly and dose-effect dependently.Conclusion L01 not only has the protective effect on HUEVC,but also increases fibrinolytic activity and facilitate spontaneous thrombolysis.