高密度脂蛋白中的1-磷酸鞘氨醇对心肌细胞生存信号通路的影响

Effect of sphingosine-1-phosphate(S1P) in HDL on cardiomyocyte survival signaling pathway

目的:观察高密度脂蛋白(HDL)不同组分中1-磷酸鞘氨醇(S1P)的含量对心肌细胞AKT和ERK1/2信号转导通路的影响,探讨HDL对心肌细胞的保护作用。方法:应用超速离心法和层析法,分离不同组分HDL;应用地高辛核素标记法检测各组分中S1P含量。给予小鼠心肌细胞不同S1P含量的HDL组分和S1P1、S1P3受体抑制剂VPC23019刺激后,用蛋白印迹法检测AKT和ERK1/2转导通路磷酸化水平的变化。结果 :与对照组比较,受不同HDL组分刺激后,成年小鼠心肌细胞AKT和ERK1/2磷酸化水平升高,且随着各组分中S1P含量升高,磷酸化水平呈上升趋势,而S1P1及S1P 3受体抑制剂VPC23019能明显阻断此种作用。结论:不同HDL组分通过细胞膜上的S1P受体,激活PI3K-AKT和MEK-ERK1/2信号通路,该作用通过S1P1和S1P3受体介导;HDL可能通过S1P发挥心肌保护作用。

Objective By observing the influence of sphingosine-l-phosphate （S1P） in various components of HDL on cardiomyocyte AKT and ERK1/2 signaling pathway to investigate the protective effect of HDL on cardiomyocytes. Methods Different components of HDL were separated by uhracentrifugation and chromatographic analysis. The content of S1P in various components of HDL was detected by digoxin nucleotide labeling method. Mouse cardiomyocytes were treated with different HDL components and VPC23019 （a S1P1, and S1P3 receptor antagonist）. Western blot was used to detect the change of phosphorylated AKT and ERK 1/2 signaling pathway. Results Compared with control group, the level of phosphorylated AKT and ERK 1/2 increased after stimulated with different HDL components,and the level of increase was correlated with the content of S1P in different HDL components. This effect was abrogated by VPC 23019. Conclusions Various components of HDL could activate PI3K-AKT and MEK-ERK1/2 signaling pathway via the S1P receptor on cell membrane. This effect was completely inhibited by S1P1 and S1P3 receptor antagonist VPC23019. Myocardial protection effect of HDL might be through S1P and was mediated by S1P1 and SIP3 receptors.