GLP-1 通过 SDF-1/CXCR4 信号通路调控人脐血内皮祖细胞增殖、 分化和凋亡

摘要:目的 探讨胰高血糖素样肽 1（GLP-1）调控人脐血内皮祖细胞（EPCs）增殖、 分化与凋亡的分子机制。方法 从健康孕妇脐带血分离和培养 EPCs， 以 2×105 密度接种于 6 孔细胞板， 分别转染空载体质粒（对照组）、 pcD⁃ NA3-GLP-1 质粒（GLP-1 组）、 pcDNA3-GLP-1 质粒+AMD3100（GLP-1+AMD3100 组）及单纯 AMD3100（AMD3100 组）。将 pcDNA3-GLP-1 质粒转染 EPCs， 以 25 μmol/L AMD3100 阻断体外培养的 EPCs 的基质细胞衍生因子 （SDF- 1） /趋化因子受体 4（CXCR4）信号通路 1 h。采用 RT-PCR 检测分化和凋亡相关基因 PPARγ、 C/EBPα与 Caspase-3 基因表达， MTT 比色法检测细胞增殖能力， Caspase-3 活性检测试剂盒测定 Caspase-3 活性。结果 与对照组相比， GLP-1 过表达显著提高了 C/EBPα及 PPARγ mRNA 表达， 促进了 EPCs 细胞增殖， 降低了 Caspase-3 mRNA 表达和 Caspase-3 活性 （均 P < 0.05）。当 SDF-1/CXCR4 信号通路被阻断后， GLP-1 对 C/EBPα及 PPARγ mRNA 表达、 EPCs 细胞增殖的促进作用， 以及对 Caspase-3 mRNA 表达和 Caspase-3 活性的抑制作用均明显减弱（均 P < 0.05）。结论 GLP-1 可通过调节 SDF-1/CXCR4 信号通路促进 EPCs 增殖与分化， 抑制其凋亡。

GLP-1 regulates proliferation,differentiation and apoptosis of endothelial progenitor cells isolated from human umbilical cord blood by targeting the SDF-1/CXCR4 signaling pathway

Abstract: Objective To investigate the molecular regulatory mechanism of glucagon like peptide 1 (GLP-1) on prolif⁃ eration, differentiation and apoptosis of human umbilical cord blood endothelial progenitor cells (EPCs). Methods EPCs were isolated from the umbilical cord blood of healthy pregnant women and cultured in 6- hole cell plate at 2×105 density in vitro, transfected with empty vector plasmid (control group), pcDNA3-GLP-1 plasmid (GLP-1 group), pcDNA3-GLP-1plas⁃ mid +AMD3100 (GLP-1+AMD3100 group) and simple AMD3100 (AMD3100 group). The pcDNA3-GLP-1 was transfected into EPCs. The 25μmol/L AMD3100 was used to block the SDF-1/CXCR4 signal pathway of EPCs for 1 h. The cell prolifera⁃ tion was determined by MTT method. The mRNA expressions of differentiation and apoptosis related genes PPARγ, C/EBPα and Caspase-3 were investigated by RT-PCR, and Caspase-3 activity was determined by Caspase-3 activity assay kit. Re⁃ sults Compared to control group, AMD3100 inhibitor showed no effects on cell proliferation, differentiation and apoptosis, while over-expression of GLP-1 in EPCs obviously promoted cell proliferation, and differentiation related genes PPARγ and C/EBPα mRNA expression, but down-regulated mRNA expression and the activity of Caspase-3 significantly (P < 0.05), in⁃ dicating that GLP-1 increased proliferation and differentiation of EPCs while decreased cell apoptosis. When the SDF-1/CX⁃ CR4 signaling pathway was blocked by AMD3100, over-expression of GLP-1 induced promotion of cell proliferation, and the differentiation was decreased significantly and the apoptosis was significantly increased (P < 0.05). Conclusion These data confirm that GLP-1 might promote EPCs proliferation and differentiation, and inhibit cell apoptosis through the regula⁃ tion of the SDF-1/CXCR4 signaling pathway.