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目的 研究肿瘤坏死因子 α(TNF α)对人脐静脉内皮细胞 (HUVECs)纤溶酶原激活物抑制剂 (PAI 1)活性及mRNA水平的影响 ,以及促分裂原活化蛋白激酶 (MAPK)在其中的作用。 方法 进行HUVECs的培养和鉴定。加入不同浓度TNF α ,并选择最佳时间条件。采用发色底物法测定PAI 1活性 ,Northernblot法检测PAI 1mRNA的水平。运用MAPK激酶抑制剂PD980 5 9观察对上述PAI 1l表达系统的作用。 结果 不同浓度TNF α(5× 10 4IU L、1× 10 5IU L、2× 10 5IU L和 4× 10 5IU L)均明显增高HUVECsPAI 1的活性 (P <0 0 1) ,1× 10 5IU LTNF α作用不同时间 (12、18、2 4h) ,PAI 1活性均明显增加 (P <0 0 1)。 1× 10 5IU LTNF α作用 18h时 ,PAI 1mRNA水平为正常对照组的 2 88倍。MAPK激酶抑制剂PD980 5 9能显著抑制TNF α对PAI 1活性和mRNA表达增强的作用。 结论 TNF α增强HUVECsPAI 1活性与mRNA表达 ;PAI 1活性提高与其mRNA表达增加呈正相关 ;MAPK途径在TNF α诱导PAI 1反应中起着重要作用。
Objective To investigate the effect of tumor necrosis factor α (TNFα) on the activity and mRNA level of plasminogen activator inhibitor (PAI 1) in human umbilical vein endothelial cells (HUVECs) and the effect of mitogen-activated protein kinase (MAPK) Role. Methods HUVECs were cultured and identified. Add different concentrations of TNFα, and select the best time conditions. The activity of PAI 1 was determined by chromogenic substrate method. The level of PAI 1 mRNA was detected by Northern blot. The MAPK kinase inhibitor PD98059 was used to observe the effect on the above PAI11 expression system. Results TNFα (5 × 10 4 IU L, 1 × 10 5 IU L, 2 × 10 5 IU L and 4 × 10 5 IU L) significantly increased the activity of PAI 1 in HUVECs (P <0.01), 1 × 10 5 IU LTNF α at different time (12,18,24 h), PAI 1 activity were significantly increased (P <0.01). The PAI 1 mRNA level was 888 times higher than that of the normal control group at 1 × 10 5 IU LTNF α for 18 hours. MAPK kinase inhibitor PD98059 can significantly inhibit the effect of TNFa on PAI1 activity and mRNA expression. Conclusions TNFα enhances the activity of PAI 1 and the mRNA expression of HUVECs. The increase of PAI 1 activity is positively correlated with the increase of its mRNA expression. The MAPK pathway plays an important role in the induction of PAI 1 by TNF α.