人脐静脉内皮细胞内S-腺苷同型半胱氨酸升高与MCP-1表达的关系

RELATIONSHIP OF INCREASED INTRACELLULAR S-ADENOSYLHOMOCYSTEINE WITH MONOCYTE CHEMOATTRACTANT PROTEIN -1 EXPRESSION IN HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS

目的探讨胞内S-腺苷同型半胱氨酸(S-adenosylhomocysteine,SAH)聚集损伤血管内皮细胞的分子基础,为阐明膳食高蛋氨酸摄入促进心血管疾病的病理机制提供实验依据。方法以永生化的人脐静脉内皮细胞(HUVEC)为研究对象,经不同浓度的S-腺苷同型半胱氨酸水解酶(SAHH)强效抑制剂3-deazaadenosine(DZA)处理24,48或72 h后,利用酶联免疫吸附测定法(ELISA)测定HUVEC内炎性分子单核细胞趋化蛋白-1(MCP-1)的含量,荧光定量-PCR法(qRT-PCR)检测MCP-1 mRNA的相对表达量,甲基化特异PCR法(MSP)分析MCP-1基因启动子甲基化状态。结果HUVEC经DZA处理后,与正常对照相比,胞内MCP-1的含量升高,mRNA的相对表达量上调,但其启动子甲基化方式并不发生改变。结论内皮细胞SAH升高上调MCP-1的表达可能是膳食高蛋氨酸摄入促进心血管疾病的分子机制,但这种作用与MCP-1基因启动子的甲基化状态无关。

Objective To explore the molecular basis of vascular endothelial cell＇s injury by cellular S-adenosylhomocysteine （SAH） accumulation, and the mechanism for cardiovascular disease induced by dietary high methionine intake. Method After human umbilical vein endothelial cells （HUVEC） were treated without （normal） or with different concentrations of potent S-adenosylhomocysteine hydrolase （SAHH） inhibitor 3-deazaadenosine （DZA） for 24, 48 or 72h, the level of intracellular inflammatory monocyte chemoattractant protein-1 （MCP-1） was measured with enzyme linked immunosorbent assay （ELISA）. Then, the relative expression of MCP-1 mRNA was detected with quantitative reverse transcription polymerase chain reaction （qRT-PCR）. Furtheremore, the methylated state of MCP-1 gene promoter was analyzed with methylation special PCR （MSP） method. Results The level of intracellular MCP-1 was increased in HUVEC incubated with DZA than normal （P〈0.05）, and the relative expression of MCP-1 mRNA was also up- regulated. But there were no changes of promoter methylation of MCP-1 gene. Conclusion The up-regulation of MCP-1 expression induced by intracellular increased SAH, which was not through alteration of gene promoter methylation, and might be the molecular mechanism of promoting cardiovascular disease by dietary high methionine intake.