Xia L, Wang X X, Hu X S, Guo X G, Shang Y P, Chen H J, Zeng C L, Zhang F R, Chen J Z
Department of Cardiovascular Diseases, the First Affiliated Hospital, Medical School of Zhejiang University, Hangzhou, PR China.
Br J Pharmacol. 2008 Oct;155(3):387-94. doi: 10.1038/bjp.2008.272. Epub 2008 Jun 30.
Recent studies have shown that resveratrol increased endothelial progenitor cells (EPCs) numbers and functional activity. However, the mechanisms remain to be determined. Previous studies have demonstrated that increased EPC numbers and activity were associated with the inhibition of EPC senescence, which involves activation of telomerase. Therefore, we investigated whether resveratrol inhibits the onset of EPC senescence through telomerase activation, leading to potentiation of cellular activity.
After prolonged in vitro cultivation, EPCs were incubated with or without resveratrol. The senescence of EPCs were determined by acidic beta-galactosidase staining. The bromo-deoxyuridine incorporation assay or a modified Boyden chamber assay were employed to assess proliferative or migratory capacity, respectively. To further examine the underlying mechanisms of these effects, we measured telomerase activity and the phosphorylation of Akt by western blotting.
Resveratrol dose dependently prevented the onset of EPCs senescence and increased the proliferation and migration of EPCs. The effect of resveratrol on senescence could not be abolished by eNOS inhibitor or by an oestrogenic receptor antagonist. Resveratrol significantly increased telomerase activity and Akt phosphorylation. Pre-treatment with the PI3K inhibitor, LY294002, significantly attenuated resveratrol-induced telomerase activity.
Resveratrol delayed the onset of EPC senescence and this effect was accompanied by activation of telomerase through the PI3K-Akt signalling pathway. The inhibition of EPCs senescence by resveratrol might protect EPCs against dysfunction induced by pathological factors in vivo and improve EPC functional activities in a way that may be important for cell therapy.
近期研究表明,白藜芦醇可增加内皮祖细胞(EPCs)数量及功能活性。然而,其机制仍有待确定。既往研究显示,EPCs数量及活性增加与EPC衰老的抑制有关,而这涉及端粒酶的激活。因此,我们研究了白藜芦醇是否通过激活端粒酶抑制EPC衰老的发生,从而增强细胞活性。
经过长时间体外培养后,将EPCs与白藜芦醇一起或不与白藜芦醇一起孵育。通过酸性β-半乳糖苷酶染色确定EPCs的衰老情况。分别采用溴脱氧尿苷掺入试验或改良的博伊登小室试验评估增殖或迁移能力。为进一步研究这些作用的潜在机制,我们通过蛋白质印迹法检测端粒酶活性和Akt的磷酸化。
白藜芦醇剂量依赖性地阻止EPCs衰老的发生,并增加EPCs的增殖和迁移。eNOS抑制剂或雌激素受体拮抗剂不能消除白藜芦醇对衰老的影响。白藜芦醇显著增加端粒酶活性和Akt磷酸化。用PI3K抑制剂LY294002预处理可显著减弱白藜芦醇诱导的端粒酶活性。
白藜芦醇延迟了EPC衰老的发生,且该作用伴随着通过PI3K-Akt信号通路激活端粒酶。白藜芦醇对EPC衰老的抑制可能保护EPCs免受体内病理因素诱导的功能障碍,并以一种可能对细胞治疗很重要的方式改善EPC的功能活性。