Study Subjects Source of cells EPC markers Effect of aging Reference Rauscher et al. 2003 6-month-old versus 1-month-old ApoE−/− mice BM CD31+/CD45− Reduced EPC numbers; progressive development of atherosclerosis [16 ] Zhang et al. 2006 12-month-old versus 3-month-old BALB/C mice BM CD117+/CD34+/Flk1+ Decrease in numbers; reduced EPC proliferation, migration, and phagocytic functions [17 ] Sugihara et al. 2007 18-month-old versus 2-month-old C57Bl/6J mice BM AC133+/CD34+ and CD34+/VEGFR2+ No difference in numbers of EPCs; impaired VEGF production and EPC migration [18 ] Shimada et al. 2004 Klotho mutant versus wild type miceBM and peripheral blood c-kit+/CD31+ and CD34+/CD31+ Decrease in EPC numbers postischemia [19 ] Chang et al. 2007 18–24-month-old versus 4–6-month-old C57Bl/6J Peripheral blood and BM CD11b−/Flk1+ and Sca1+/c-kit+/Lin− Decrease in CD11b−/Flk1+ numbers in blood, but not Sca1+/c-kit+/Lin− cells in BM postischemia [11 ] 68–95-year-old versus 18–35-year-old human Peripheral blood AC133+ No difference in EPC numbers at baseline Zhuo et al. 2010 15-16-month-old versus 2-month-old rat Peripheral blood and spleen CD34+/KDR+ Decreased numbers in response to ischemia, but not at baseline (prior to ischemia) [20 ] Shao et al. 2011 24–26-month-old versus 2-month-old C57Bl/6J mice BM Lin−/Sca1+ and Lin−/Sca1+/CXCR4+ Decrease in Lin−/Sca1+/CXCR4+, but not Lin−/Sca1+ subpopulation [21 ] Boon et al. 2011 16–18-month-old versus 1-month-old C57Bl/6J mice Peripheral blood Lin−/Sca1+/c-kit+, Sca1+/c-kit, and Sca1+/Flk1+ Decrease in all 3 populations [22 ] Scheubel et al. 2003 Patients with CAD; 69 years old versus younger patients Peripheral blood AC133+/CD34+ Reduced basal circulating EPC levels [23 ] Heiss et al. 2005 Healthy elderly (average 61 years old) versus healthy young subjects (average 25 years old) Peripheral blood CD133+/KDR+ and CD34+/KDR+ Comparable levels of EPCs [24 ]
