人参皂甙对血管内皮细胞纤溶酶原激活物抑制剂1和核因子-κB的作用

Effects of ginsenosides on lipopolysaccharide-induced plasminogen activator inhibitor type-1 and NF-kappa B expression in vascular endothelial cells

目的 研究人参皂甙对内毒素脂多糖 (lipopolisaccharide ,LPS)致血管内皮细胞纤溶酶原激活物抑制剂 1(plasminogenactivatorinhibitortype 1,PAI 1)表达和核因子 κB (NF κB)激活的影响 ,探讨人参皂甙对心血管疾病的保健和防治机制。方法 用酶消化法培养人脐静脉内皮细胞(humanumbilicalveinendothelialcells ,HUVEC) ;ELISA方法检测HUVEC条件培养液PAI 1蛋白量 ;Northernblot检测HUVECPAI 1的mRNA表达 ;免疫荧光检测HUVECNF κB的分布 ;电泳迁移变动检测法检测HUVEC核提取物NF κBDNA结合活性。结果 LPS能使HUVECPAI 1蛋白及mRNA表达显著增强 ,人参皂甙则使LPS的这种作用明显减弱。免疫荧光显示 ,LPS促使HUVECNF κB向细胞核内转移 ,人参皂甙则能阻止LPS诱导的NF κB核内转移 ;电泳迁移变动检测法研究发现 ,人参皂甙能完全阻止LPS致内皮细胞核提取物NF κBDNA结合活性。结论 人参皂甙对心血管疾病的防治机制之一是通过拮抗LPS致HUVECPAI 1的表达。而且 ,这种拮抗作用可能通过NF κB途径来转导。

Objective To investigate the mechanism of ginsenosides in the protection and treatment of cardiovascular diseases by studying the effects of ginsenosides on lipopolysaccharide-induced plasminogen activator inhibitor type-1 (PAI-1) expression and NF-kappa B activation in vascular endothelial cells. Methods Human umbilical vein endothelial cells (HUVEC) were cultured by trypsin digestion method. PAI-1 was measured in the conditioned medium of HUVEC by a specific enzyme-linked immunosorbent assay (ELISA), whereas a specific PAI-1 mRNA expression was determined by Northern blot. An immunofluorescence method was used to determine NF-kappa B distribution in HUVEC, and electrophoretic mobility shift assays (EMSA) were performed using nuclear extracts from HUVEC and NF-kappa B-binding oligonucleotides. Results Treatment of HUVEC with LPS resulted in a significant increase in PAI-1 antigen level. Ginsenosides inhibited this LPS-induced upregulation of PAI-1 markedly. This effect was also confirmed on the level of specific PAI-1 mRNA expression by Northern blot. Furthermore, LPS could stimulate NF-kappa B nuclear translocation and ginsenosides could inhibit this change in HUVEC measure by immunofluoresence. The result of EMSA also showed that ginsenosides completely abolished LPS-induced NF-kappa B DNA binding activity in nuclear extracts from HUVEC treated with LPS together with ginsenosides. Conclusion Ginsenosides counteract endothelial cell activation by inhibition LPS-induced PAI-1 expression in HUVEC. Its interference with the NF-kappa B pathway may contribute to this effect. The ability of ginsenosides to counteract LPS effect on endothelial cells may be one of the mechanisms explaining its efficacy in the protection and treatment of cardiovascular diseases.