低密度脂蛋白激活人肾小管上皮细胞核转录因子κB与纤溶酶系统表达

Activation of nuclear factor-κB in cultured human proximal tubular cell by low density lipoprotein in expression of plasminogen activator inhibitor-1 and tissue plasmin activator

目的 探讨在低密度脂蛋白 (LDL)环境中 ,人近端肾小管上皮细胞 (HKC)纤溶酶原抑制物 (PAI 1)和组织纤溶酶激活因子 (tPA)异常与核转录因子 κB(NF κB)激活的关系 ,及洛伐他汀 (Lov)的改善作用。方法 体外培养HKC ,用LDL刺激HKC ,并与Lov共孵育 ,发色底物法检测细胞上清液中PAI 1和tPA活性 ,逆转录聚合酶链反应后 ,观察HKC合成PAI 1和tPAmRNA表达 ,在共聚焦显微镜下 ,检测NF κB的表达。结果 LDL可激活NF κB的亚单位P6 5 ,使HKC培养上清液中PAI 1活性增加 ,mRNA表达为对照组的 2 .5倍。tPA活性由对照组的 6 .2 2± 0 .5 2IU/ml降至LDL组的 4 .9± 0 .11IU/ml(P <0 .0 5 ) ,mRNA表达降低 ,Lov可部分或全部逆转LDL的作用 ,甲羟戊酸可部分阻遏Lov作用。结论 LDL影响PAI 1/tPA活性及mRNA表达 ,可能和NF κB激活有关 ,Lov可通过影响NF κB的激活 ,逆转LDL的作用。

Objective To investigate the activity and mRNA expression of plasminogen autivator inhibitor (PAI 1) and tissture plasmin activator (tPA) stimulated by low density tipoprotein (LDL) on cultured human proximal tubular cell (HKC), which was a cell line of human proximal tubular cell. To show whether LDL can lead to the activation of nuclear factor κB NF κB, and weather the effect can be reversed by Lovastatin, a kind of 3 hydroxy 3 methylglutaryl coenzyme, a reductase inhibitors (HRI). Methods Chromogenic substance was used to show the activity of tPA and PAI 1, RT PCR showed the mRNA expression of PAI 1 and tPA. The expression of P65 in nuclear was showed by Laser confocal microscopy. Results LDL could up regulate the activity of PAI 1 , down regulate the activity of tPA, which was decreased from 6.22±0.52 IU/ml to 4.9±0.11 IU/ml (in control vs LDL, P <0.05). The expression of PAI 1 mRNA was increased to 2.5 times respectively in LDL. Co cultured with Lovastatin (1 μmol/L) and LDL, the activity of PAI 1/tPA, and even the mRNA expression of PAI 1 could be reversed completely. P65 subunit of NF κB were increased significantly in LDL, and could be decreased by Lovastatin, Mevolin could partly recover the effect of Lovastatin. Conclusion LDL could influence the activity and mRNA expression of PAI 1 and tPA. It may be connected with the activation of NF κB