不稳定性心绞痛患者循环内皮祖细胞与血管内皮功能的变化

目的探讨不稳定性心绞痛患者外周血循环内皮祖细胞(EPCS)与血管内皮功能的变化。方法采用高分辨率血管超声法检测30例不稳定性心绞痛患者与30例正常者作对照组肱动脉血流介导的内皮依赖性血管舒张功能(FMD)及硝酸甘油介导的非内皮依赖性血管舒张功能(NMD);流式细胞仪测定外周血中CD34+单个核细胞的水平;外周血分离单个核细胞一定条件下培养2周,免疫组织化学技术鉴定培养贴壁细胞表面标志CD34的表达;倒置荧光显微镜鉴定贴壁细胞FITC-UEA-I和DII-ACLDL双染色阳性细胞为正在分化的EPCS。结果不稳定性心绞痛组FMD明显低于对照组[(5·85±3·04)%比(8·81±4·48)%,P<0·05];NMD在两组中差异无统计学意义[(13·60±5·03)%比(14·18±4·50)%,P>0·05];CD34+细胞水平明显高于对照组[(0·13±0·05)%比(0·09±0·04)%,P<0·05];FMD与CD34+细胞水平呈负相关(R=-0·385,P<0·05)。培养的贴壁细胞免疫组化显示CD34阳性,倒置荧光显微镜显示这些贴壁细胞FITC-UEA-I和DII-ACLDL双染色阳性。结论不稳定性心绞痛患者CD34+细胞增加和血管内皮功能受损,提示循环EPCS增加可能是对急性冠状动脉缺血和内皮损伤的代偿反应。

Change in endothelial progenitor cells and endothelial function in patients with unstable angina pectoris

OBJECTIVE: To investigate the relationship between endothelial progenitors cells (EPCs) and endothelium-dependent vasodilation in patients with unstable angina pectoris. METHODS: Thirty patients with unstable angina pectoris (UAP) and thirty control subjects were recruited. Flow-mediated dilation (FMD) in the brachial artery was evaluated by using ultrasound Doppler flow method. The number of circulating EPCs was analyzed by flow cytometry analysis. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. CD34 antigen of adherent cells was identified by immunohistochemical assay. EPCs were characterized as adherent cells double positive for FITC-UEA-I binding and DiI-acLDL uptake by direct fluorescent staining under inverted fluorescent microscope. RESULTS: FMD was significantly impaired in the UAP group compared with the control group (5.93% +/- 2.67% vs 11.1% +/- 4.36%, P < 0.05). There was no significant difference in NMD between two groups (13.60% +/- 5.03% vs 14.18% +/- 4.50%, P > 0.05). The number of CD34(+) cells significantly increased in the UAP group compared with the control group (0.13% +/- 0.05% vs 0.09% +/- 0.04%, P < 0.05). There was a negative association between impaired FMD and increased CD34(+) cell (r = -0.385, P < 0.05). A positive antigen of CD34 of adhesion cells and double positive adhesion cells were found. CONCLUSION: This study shows that the levels of peripheral CD34(+) cells in patients with UAP increase with an impaired endothelial function. The increase in EPCs may be an important compensatory response to acute coronary ischemia and impaired endothelium in patients with UAP.