1-磷酸鞘氨醇抑制TGF-β诱导的人脐静脉内皮细胞间充质转化

Sphingosine 1-phosphate inhibits TGF-β-induced endothelial-to-mesenchymal transition in human umbilical vein endothelial cells

目的:探讨1-磷酸鞘氨醇(S1P)对转化生长因子β(TGF-β)诱导的人脐静脉内皮细胞(HUVECs)内皮-间充质转化(End-MT)的作用及机制。方法:根据实验分组采用TGF-β、S1P和S1P受体1(S1PR1)抑制剂VPC23019处理HUVECs。Western blot检测内皮细胞标志物(CD31和VE-cadherin)、间充质细胞标志物(α-平滑肌肌动蛋白和成纤维细胞特异性蛋白1)、S1PR1和p-Smad3的表达;免疫荧光染色检测Smad3的核转位。结果:与TGF-β组相比,TGF-β+S1P组End-MT进程显著被抑制,Smad3磷酸化及核转位显著减少(P<0.05);而加入S1PR1抑制剂后,上述S1P的作用被逆转(P<0.05)。结论:在HUVECs中,S1P通过S1PR1抑制TGF-β诱导的End-MT,该效应可能与Smad3磷酸化及核转位水平的降低有关。

AIM:To investigate the effect of sphingosine 1-phosphate(S1 P)on endothelial-to-mesenchymal transition(End-MT)in human umbilical vein endothelial cells(HUVECs)induced by transforming growth factor-β(TGF-β)in vitro.METHODS:The HUVECs in different groups were treated with TGF-β,S1 P or sphingosine 1-phosphate receptor 1(S1 PR1)inhibitor VPC23019.Western blot was used to detect the protein levels of endothelial cell markers(CD31 and VE-cadherin),mesenchymal cell markers(α-smooth muscle actin and fibroblast-specific protein 1),S1 PR1 and p-Smad3.Immunofluorescence staining was used to analyze the nuclear translocation of Smad3.RESULTS:Compared with TGF-β group,the process of End-MT was significantly inhibited,and the phosphorylation and nuclear translocation of Smad3 were significantly reduced in TGF-β+S1 P group(P<0.05).However,the above effects of SP1 were reversed after the addition of S1 PR1 inhibitor(P<0.05).CONCLUSION:S1 P inhibits TGF-β-induced End-MT via S1 PR1 in HUVECs.This effect may be associated with decreases in Smad3 phosphorylation and nuclear translocation.