主动脉夹层患者循环内皮祖细胞或许经由氧化应激机制加速细胞衰老

Circulating Endothelial Progenitor Cell in Patients with Aortic Dissection May Accelerate Cell Senescence via Elevated Intracellular Oxidative Stress

目的探讨主动脉夹层患者循环内皮祖细胞是否经由氧化应激机制加速衰老。方法临床选取疑似主动脉夹层患者并经主动脉CTA检查后分为对照组和主动脉夹层组,抽取外周血分离单个核细胞群,流式细胞分选术分离和计数内皮祖细胞,应用层粘连蛋白粘附法、改良的Boyden小室及MTT法测定内皮祖细胞的粘附、迁移和增殖功能,应用Western blot检测内皮祖细胞衰老相关的p16INK4a和SIRT1蛋白水平,并测定细胞内反应氧类物质水平。结果与对照组相比,主动脉夹层组循环CD34+CD133+KDR+内皮祖细胞数量明显减少(P<0.01),且细胞粘附、迁移和增殖功能明显降低(P<0.05);Western blot结果显示细胞衰老相关的p16INK4a蛋白水平明显升高,而抗衰老蛋白SIRT1表达水平明显降低,细胞内反应氧类物质水平明显增加(P<0.05)。结论不断增加的细胞内反应氧类物质致主动脉夹层患者循环内皮祖细胞的粘附、增殖和迁移功能受损,最终加速循环内皮祖细胞衰老。

Aim To determine if circulating endothelial progenitor cells in patients with aortic dissection accelerated cell senescence via oxidative stress mechanism. Methods All patients with a symptom of chest pain were divided into control group and aortic dissection group according to the result of CT angiography. Endothelial progenitor cells were isolated and identified by flow cytometry analysis. The adhesion,migration and proliferation functions of endothelial progenitor cells were separately measured by the methods fibronectin adhesion,modified Boyden chamber and MTT array.Western blot was used to detect the protein level of p16INK4 a and SIRT1. The level of intracellular reactive oxygen species was analyzed by the labeled H2DCF-DA method. Results The number of circulating CD34CD133KDR-positive endothelial progenitor cells in patients with aortic dissection decreased sharply( P < 0. 01) and cellular functions such as adhesion,migration and proliferation were damaged when compared with those in control group( P < 0. 05). The protein level of the pro-senescent marker p16INK4 a was found to upregulate significantly and meanwhile the expression of anti-senescent protein SIRT1 was decreased remarkably in the aortic dissection group( P < 0. 05). The level of intracellular reactive oxygen species in patients with aortic dissection was increased severely( P < 0. 05). Conclusions The accumulating intracellular reactive oxygen species were found to make those dysfunctions of circulating endothelial progenitor cells such as proliferation,adhesion and migration which probably accelerated endothelial progenitor cell senescence in patients with aortic dissection.