他汀类药物对外周血内皮祖细胞的影响

本文旨在探讨他汀类药物氟伐他汀对外周血内皮祖细胞(endothelialprogenitor cells,EPCs)数量和功能的影响.用密度梯度离心从外周血获取单个核细胞,将其接种在人纤维连接蛋白(humanfibronectin)包被的培养板中,培养7 d后,收集贴壁细胞,加入不同浓度氟伐他汀(分别为0.01、0.1、1、10μmol/L)和辛伐他汀(1μmol/L),培养一定的时间(6、12、24、48 h).用激光共聚焦显微镜鉴定FITC-UEA-I和DiI-acLDL双染色阳性细胞为正在分化的EPCs,用流式细胞仪检测其表面标志进一步鉴定EPCs,在倒置荧光显微镜下计数.采用MTT比色法、改良的Boyden小室、粘附能力测定实验和体外血管生成试剂盒观察EPCs的增殖能力、迁移能力、粘附能力和体外血管生成能力.结果显示,氟伐他汀可显著增加外周血EPCs的数量,并且EPCs数量随氟伐他汀浓度增加及作用时间延长而增加,1μmol/L浓度氟伐他汀作用24h对EPCs的数量影响最为显著(较对照组增加15倍,P＜0.05).在动物实验中,喂养氟伐他汀3周后,大鼠的EPCs也较对照组增加2倍(P＜0.05),进一步支持了体外实验的结果.氟伐他汀和辛伐他汀也显著改善外周血EPCs的粘附能力、迁移能力、增殖能力和体外血管生成的能力,相同浓度的氟伐他汀和辛伐他汀(1μmol/L)对EPCs数量和功能的影响并无显著差异.上述观察结果提示他汀类药物可增加EPCs的数量,改善EPCs功能.

Statins contribute to enhancement of the number and the function of endothelial progenitor cells from peripheral blood

The aim of the present study was to investigate whether fluvastatin augments the number of endothelial progenitor cells (EPCs), and promotes EPCs proliferation, migration and adhesion. Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation. The cells were then plated on fibronectin-coated culture dishes. After being cultured for 7 d, the attached cells were stimulated with fluvastatin (final concentrations: 0.01, 0.1, 1, 10 micromol/L), simvastatin (1 micromol/L) or a vehicle for the respective time points (6, 12, 24 and 48 h). EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPCs were further documented by demonstrating the expression of KDR, VEGFR-2 and AC133 with flow cytometry. EPCs proliferation, migration and in vitro vasculogenesis activity were assayed by MTT assay, modified Boyden chamber assay and in vitro vasculogenesis kit, respectively. EPCs adhesion assay was performed by replating it on fibronectin-coated dishes, and the adherent cells were then counted. In addition, we also studied EPCs culture assay of peripheral blood from fluvastatin-treated animals in vivo. Incubation of isolated human MNCs with fluvastatin dose- and time-dependently increased the number of EPCs, while reached the maximum 24 h after the administration at 1 micromol/L, (2.5-fold increase, P<0.05). Moreover, treatment of rats with fluvastatins elevated the number of EPCs (3-fold increase, P<0.05), thus extending the in vitro data. In addition, fluvastatin also promoted EPC proliferation, migration, adhesion and in vitro vasculogenesis in a concentration-dependent manner. The effects of fluvastatin on EPCs were compared with those of simvastatin at the same concentration (1 micromol/L), with a result of no statistical difference. The results of the present study define a novel mechanism of the action of statins: the augmentation of EPCs with enhanced functional activity.