title: Resveratrol-induced augmentation of telomerase activity delays senescence of endothelial progenitor cells.
abstract: BACKGROUND
  Previous studies have shown that resveratrol increases endothelial progenitor cell (EPC) numbers and functional activity. Increased EPC numbers and activity are associated with the inhibition of EPC senescence. In this study, we investigated the effect of resveratrol on the senescence of EPCs, leading to potentiation of cellular function.
  
  
  METHODS
  EPCs were isolated from human peripheral blood and identified immunocytochemically. EPCs were incubated with resveratrol (1, 10, and 50 µmol/L) or control for specified times. After in vitro cultivation, acidic β-galactosidase staining revealed the extent of senescence in the cells. To gain further insight into the underlying mechanism of the effect of resveratrol, we measured telomerase activity using a polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA) technique. Furthermore, we measured the expression of human telomerase reverse transcriptase (hTERT) and the phosphorylation of Akt by immunoblotting.
  
  
  RESULTS
  Resveratrol dose-dependently inhibited the onset of EPC senescence in culture. Resveratrol also significantly increased telomerase activity. Interestingly, quantitative real-time PCR analysis demonstrated that resveratrol dose-dependently increased the expression of the catalytic subunit, hTERT, an effect that was significantly inhibited by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers (wortmannin). The expression of hTERT is regulated by the PI3-K/Akt pathway; therefore, we examined the effect of resveratrol on Akt activity in EPCs. Immunoblotting analysis revealed that resveratrol led to dose-dependent phosphorylation and activation of Akt in EPCs.
  
  
  CONCLUSIONS
  Resveratrol delayed EPCs senescence in vitro, which may be dependent on telomerase activation.
authors.affiliation: Department of Cardiology, Taizhou People's Hospital, Second Affiliated to Medical College of Yangzhou University, Taizhou, Jiangsu 225300, China.
authors.forename: Xiao-Bin
authors.initials: XB
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Yin
authors.forename: Xiang-Qing
authors.initials: XQ
authors.lastname: Kong
authors.forename: Qi-Fei
authors.initials: QF
authors.lastname: Rong
authors.forename: Ai-Wu
authors.initials: AW
authors.lastname: Shi
authors.forename: Ke-Jiang
authors.initials: KJ
authors.lastname: Cao
mesh_terms: D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D006801:Humans; D000077185:Resveratrol; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D013267:Stilbenes / Q000633:toxicity*; D019098:Telomerase / Q000378:metabolism*
chemical_list: D013267:Stilbenes; D019098:Telomerase; D000077185:Resveratrol