PPARα激活物影响HepG-2细胞PAI-1表达机制初探  

An exploratory study on mechanism of PPARalpha activators-induced plasminogen activator inhibitor-1 expression in HepG-2 cells

作　　者：叶平[1] 贺艳丽[2] 王琼[3] 刘永学[3] 

机构地区：[1]解放军总医院老年心内科,北京100853 [2]武汉华中科技大学协和医院干细胞研究中心 [3]北京放射医学研究所药理毒理室

出　　处：《中华内科杂志》2004年第10期743-746,共4页Chinese Journal of Internal Medicine

基　　金：国家自然科学基金资助项目 ( 3 9970 3 0 1)

摘　　要：目的　探讨不同的过氧化体增殖物激活型受体α(PPARα)激活物对HepG 2细胞纤溶酶原激活物抑制剂 1(PAI 1)活性和mRNA表达的影响及其可能的机制。方法　分别以亚油酸和非诺贝特刺激HepG 2细胞 ,检测PAI 1活性和mRNA表达。基因瞬时转染含不同片段缺失的PAI 1启动子序列控制表达的报告基因质粒 ,测定亚油酸和非诺贝特诱导后的转录活性。结果　亚油酸使HepG 2细胞PAI 1mRNA表达及蛋白活性显著增加 ,而非诺贝特使其著降低。转染HepG 2细胞由PAI 1启动子全长控制的表达质粒 ,亚油酸诱导PAI 1转录活性显著增加 ,非诺贝特显著抑制其转录活性 ;转染PAI 1启动子序列核转录因子κB(NF κB)反应元件缺失的质粒时 ,亚油酸和非诺贝特仍显著增加PAI 1转录活性 ;而转染PAI 1启动子序列极低密度脂蛋白 (VLDL) /脂肪酸反应元件缺失的质粒时 ,亚油酸对PAI 1转录活性无诱导作用 ,非诺贝特可下调其转录活性。结论　PPARα可能是亚油酸增强PAI 1表达所涉及的转录因子之一 ;非诺贝特下调PAI 1表达可能涉及对NF κB信号转导途径的抑制作用。Objective To investigate the influe nce of peroxisome proliferator-activated receptor α activators on plasminogen activator inhibitor-1 (PAI-1)expression in HepG-2cells and the mechani sm possibly involved.Methods Linoleic acid and fenofibrate were used in the tr eatment of HepG-2 cell culture. PAI-1 activity and mRNA expression were determ ined with colorimetric assay and reverse transcription-polymerase chain reactio n, respectively. Using gene recombination techniques, two types of chloramphenic ol acetyl transferase(CAT) reporter gene plasmid containing different deletions in PAI-1 promoter were constructed and transiently transfected into HepG-2 cel ls, respectively. Linoleic acid and fenofibrate were added to induce the transfe cted cells. CAT activity was measured to demonstrate the transcriptional activit y of PAI-1 gene in HepG-2 cells.Results The mRNA expression and protein activity of PAI -1 was significantly induced by linoleic acid ,but was obviously suppressed by fenofibrate. In the HepG-2 cells transfected with PAI-pCAT promoter constructs the PAI-1 transcription activity was significantly induced by linoleic acid, b ut suppressed by fenofibrate. The level of PAI-1 transcription was also signifi cantly increased when co-transfected with PAI-pCAT promoter construct and PPAR α-pSG5 expression plasmid to HepG-2 cells. Furthermore, in the condition of transfection with NF-κB-response element-deletion-pCAT construct, both lino leic acid and fenofibrate increased the PAI-1 transcriptional activity, whereas in those cells transfected with VLDL/fatty acid response element-deletion-pCA T construct, fenofibrate significantly reduced PAI-1 transcriptional activity, but no change in PAI-1 transcription activity was found with linoleic acid stim ulation.Conclusions Linoleic acid induces PAI-1 activity and mRN A expression in HepG-2 cells. PPAR α may be one of transcription factors playi ng a role in the upregulation of PAI-1 gene expression. The inhibition of NF- κB signaling pathway may be invo

关 键 词：PPARα激活物 HEPG-2细胞 PAI-1 过氧化体增殖物激活型受体α激活物 纤溶酶原激活物抑制剂-1 

分 类 号：R363[医药卫生—病理学]