PI3K/Akt/eNOS信号通路在葛根素抑制ox-LDL诱导的血管内皮细胞组织因子表达中的作用

Role of PI3K/Akt/eNOS signaling pathway in inhibitory effects of pue rarin on ox-LDL-induced TF expression in vascular endothelial cells

目的:探讨磷脂酰肌醇3-激酶/蛋白激酶B/内皮型一氧化氮合酶(PI3K/Akt/eNOS)信号通路在葛根素(puerarin)抑制氧化型低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)诱导的血管内皮细胞组织因子(tissue factor,TF)表达中的作用。方法:实时荧光定量PCR检测TF的mRNA表达,Western blot检测TF和Akt的蛋白表达,硝酸盐还原酶法检测一氧化氮(nitric oxide,NO)含量。结果:与对照组相比,ox-LDL孵育内皮细胞后,内皮细胞TF的mRNA和蛋白表达升高,Akt蛋白磷酸化水平降低,细胞内NO产生减少;而葛根素预孵育内皮细胞1 h后,再用ox-LDL孵育,内皮细胞TF mRNA和蛋白表达下降,Akt蛋白磷酸化升高,细胞内NO产生增多;PI3K抑制剂LY294002和葛根素共同预孵育内皮细胞1 h后,再用ox-LDL孵育,内皮细胞TF的mRNA和蛋白表达升高,Akt蛋白磷酸化降低,细胞内NO产生减少;eNOS抑制剂NG-硝基-L-精氨酸甲酯(L-NAME)和葛根素共同预孵育内皮细胞,也明显阻断葛根素对ox-LDL诱导的内皮细胞TF mRNA和蛋白表达、细胞Akt蛋白磷酸化和细胞内NO产生的作用。结论:葛根素可通过上调PI3K/Akt/eNOS信号通路抑制ox-LDL诱导的人脐静脉内皮细胞TF mRNA和蛋白表达。

AIM ： To explore the role of phosphatidylinositiol 3-kinase/protein kinase B/endothelial nitric oxide synthase （ PI3K/Akt/eN0S） signaling pathways in the inhibitory effects of puerarin on oxidized low-density lipopro-tein （ox-LDL） -induced tissue factor （TF） expression in vascular endothelial cells. METHODS： The mRNA expression of TF was detected by real-time fluorescent quantitative PCR. The protein levels of TF and Akt was determined by Western blot. The content of the nitric oxide （NO） was measured by nitrate reduction method. RESULTS： Compared with control group, incubating endothelial cells with ox-LDL significantly induced TF expression at mRNA and protein levels and the de-phosphorylation of Akt protein, and decreased NO production. Incubation of the endothelial cells with puerarin for 1 h and then treatment of the cells with ox-LDL decreased the TF expression at mRNA and protein levels, increased Akt protein phosphorylation and intracellular NO content. Co-incubation of the endothelial cells with PI3K inhibitor LY294002 and puerarin for 1 h and then treatment of the cells with ox-LDL augmented the TF expression at mRNA and protein levels and the Akt protein dephosphorylation, and decreased NO production. Co-incubation of the endothelial cells with eNOS inhibi-tor A^G-nitro-L-arginine methyl ester （L-NAME） and puerarin significantly decreased the inhibitory effect of puerarin on ox- LDL-induced TF expression at mRNA and protein levels in the endothelial cells, and reduced Akt protein phosphorylation and NO production. CONCLUSION ： Puerarin inhibits ox-LDL-induced TF expression at mRNA and protein levels in the human umbilical vein endothelial cells via activation of PI3K/Akt/eNOS signaling pathway.