Zhu JunHui, Wang XingXiang, Chen JunZhu, Sun Jian, Zhang FuRong
Department of Cardiology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
Arch Med Res. 2006 May;37(4):484-9. doi: 10.1016/j.arcmed.2005.09.017.
Hyperhomocysteinemia (HHcy) contributes to atherosclerosis and coronary artery diseases by inducing endothelial cell injury and dysfunction. Recent studies provided increasing evidence that endothelial progenitor cells (EPCs) participated in ongoing endothelial repair. The changes of EPCs in patients with HHcy have not yet been elucidated. Therefore, we investigated the number and functional activity of EPCs in patients with HHcy.
Human EPCs were isolated and cultured from patients with HHcy (n = 30) and matched volunteers (n = 30). Circulating EPCs were enumerated as AC133+ KDR+ cells via fluorescence-activated cell sorter analysis. Additionally, EPC were expanded from human blood in vitro and identified by DiI-acLDL uptake and lectin staining by direct fluorescent staining under a laser scanning confocal microscope. EPC migration activities were determined by modified Boyden chamber assay. EPC adhesion assay was performed by replating cells on fibronectin-coated dishes and then counting adherent cells.
A significant decrease was observed in circulating EPC (AC133+ KDR+ cells) numbers in patients with HHcy compared with control subjects (63.9 +/- 11.7 cells/mL vs. 91.5 +/- 14.2 cells/mL blood, p <0.01). In addition, the numbers of EPCs also decreased in patients with HHcy after ex vivo cultivation (36.1 +/- 6.5 vs. 51.5 +/- 8.3 EPCs/x200 field, p <0.01). Both circulating EPCs and differentiated EPCs were inversely correlated with total homocysteine levels. In addition, EPCs from patients with HHcy were significantly impaired in their migratory capacity and ability to adhere to fibronectin compared with controls.
The present study demonstrated that EPC numbers and functional capacity were impaired in patients with HHcy.
高同型半胱氨酸血症（HHcy）通过诱导内皮细胞损伤和功能障碍，促进动脉粥样硬化和冠状动脉疾病的发生。最近的研究提供了越来越多的证据表明，内皮祖细胞（EPCs）参与了正在进行的内皮修复过程。HHcy患者体内EPCs的变化尚未阐明。因此，我们研究了HHcy患者体内EPCs的数量和功能活性。
从HHcy患者（n = 30）和匹配的志愿者（n = 30）中分离并培养人EPCs。通过荧光激活细胞分选分析，将循环EPCs计数为AC133+ KDR+细胞。此外，EPCs从人血液中体外扩增，并在激光扫描共聚焦显微镜下通过DiI-乙酰化低密度脂蛋白摄取和凝集素直接荧光染色进行鉴定。通过改良的Boyden小室试验测定EPCs的迁移活性。通过将细胞重新接种到纤连蛋白包被的培养皿上，然后计数贴壁细胞来进行EPCs黏附试验。
与对照组相比，HHcy患者循环EPCs（AC133+ KDR+细胞）数量显著减少（63.9±11.7个细胞/mL对91.5±14.2个细胞/mL血液，p<0.01）。此外，HHcy患者体外培养后EPCs数量也减少（36.1±6.5对51.5±8.3个EPCs/200视野，p<0.01）。循环EPCs和分化的EPCs均与总同型半胱氨酸水平呈负相关。此外，与对照组相比，HHcy患者的EPCs迁移能力和黏附于纤连蛋白的能力显著受损。
本研究表明，HHcy患者的EPCs数量和功能能力受损。
