神经酰胺阻断剂对高糖培养的人脐静脉血管内皮细胞PKB/eNOS信号通路的影响

Effects of ceramide on high glucose-induced deregulation of PKB/eNOS signaling pathway in human umbilical vascular endothelial cells

目的观察神经酰胺阻断剂对高浓度葡萄糖培养的人脐静脉内皮细胞(HUVECs)胰岛素信号通路PKB/eNOS mRNA表达的影响。方法高浓度葡萄糖培养HUVECs的基础上加用神经酰胺合成阻断剂Myriocin、DES或神经酰胺降解阻断剂NOE或PDMP干预,RT-PCR分析血管内皮细胞中IRS-1/PI3K/PKB/eNOS mRNA表达的变化。结果高浓度葡萄糖培养血管内皮细胞,对IRS-1、PI3K mRNA表达无明显影响,但能抑制PKB、eNOS mRNA表达(P<0.05);神经酰胺合成阻断剂Myriocin或DES均能改善高糖对内皮细胞PKB、eNOS mRNA表达的影响(P<0.05);神经酰胺降解阻断剂NOE或PDMP均加强高糖对PKB、eNOS mRNA表达的抑制(P<0.05)。结论神经酰胺与高糖引起的胰岛素信号通路下调有关,机体内神经酰胺水平的改变直接影响内皮细胞胰岛素信号转导通路PKB/eNOS mRNA的表达。

【Objective】 To study the effects of ceramide on high glucose-induced deregulation of IRS-1/ PI3K/PKB/eNOS signaling pathway in human vascular endothelial cells.【Methods】 This study was designed to examine the effects of high glucose on the insulin signaling pathway by RT-PCR assay.【Results】 Different concentrations of D-glucose repressed the expression of PKB,eNOS mRNA（P 0.05）,but had no effect on IRS-1,PI3K mRNA.Myriocin or DES,the blocker of ceramide synthesis,attenuated the antagonistic effect of high D-glucose on the expression of mRNA of PKB and eNOS in high D-glucose cultured HUVECs（P 0.05）.NOE or PDMP which block the degradation pathway of ceramide decreased the mRNA expression of PKB and eNOS in high D-glucose cultured HUVECs（P 0.05）.【Conclusion】 Ceramide play negative roles on insulin signaling pathway in HUVECs cultured in high D-glucose,the changes of ceramide levels directly affect the strength of the Akt/eNOS signaling pathway by the actions of the two enzymes responsible for the ceramide biosynthesis.