. 2018 Nov;14(4):233–244. doi: 10.2174/1573403X14666180726112303

Table 1.

Influence of age on circulating endothelial progenitor cell number and function.

References	Subjects	EPC Assay	Findings
Xia et al., 2012a [21]	10 young, 10 older males.	Flow cytometry CD34⁺VEGFR2⁺ EPC migration and adhesion Human EPC re-endothelialization in mice	Lower CD34⁺VEGFR2⁺ cells in elderly. Reduced migration, adhesion and re-endothelialization capacity in elderly vs. young males.
Xia et al., 2012b [27]	25 young, 22 elderly males. Resting	Flow cytometry CD34⁺VEGFR2⁺/CD133⁺VEGFR2⁺ EPC migration and adhesion Human EPC re-endothelialization in mice	Lower CD34⁺VEGFR2⁺/ CD133⁺VEGFR2⁺ cells in elderly. Reduced migration, adhesion and re-endothelialization capacity in elderly vs. young males.
Thijssen et al., 2006 [49]	8 young, 8 older sedentary males.	Flow cytometry CD34⁺VEGFR2⁺	Lower CD34⁺VEGFR2⁺ EPCs in older vs. younger males
Thum et al., 2007 [50]	10 young, 16 middle-aged, 12 older males.	Flow cytometry CD133⁺VEGFR2⁺ EPC migration and eNOS gene expression.	Lower EPC number and migration in older vs. middle-aged and younger males. Lower EPC eNOS gene expression in older vs. younger adults.
Heiss et al., 2005 [51]	20 young and 20 older male and female subjects.	Flow cytometry CD34⁺VEGFR2⁺/CD133⁺VEGFR2⁺ EPC survival, migration and proliferation assays.	No difference in EPC number between young and older subjects. Lower survival, migration and proliferation of EPCs in older subjects.
Hoetzer et al., 2007 [52]	10 young, 15 middle-aged, 21 older men.	EPC EC-CFU assay. EPC migration	Lower EC-CFU in older and middle-aged adults compared to young subjects. Lower migration of EPCs from older subjects vs. middle-aged and younger adults.
Williamson et al. 2013 [53]	EPCs from 5 young, and 4 older subjects.	EPC apoptosis, migration, and tube formation assays	No difference in proliferation, apoptosis and tube formation of EPCs from young and older subjects. EPC migration lower in older subjects vs. younger subjects.
Ross et al., 2018 [54]	107 males, aged 18-75yrs.	Flow cytometry CD34⁺CD45^dimVEGFR2⁺ Cell surface expression of CXCR4	Age inversely associated with EPC number and cell surface CXCR4 expression.
Yang et al., 2013 [55]	10 young, 10 older male subjects.	Flow cytometry: CD34⁺VEGFR2⁺ EPC migration and proliferative assays.	Lower EPC number, migration and proliferation in older vs. younger subjects.
Kushner et al., 2009 [56]	12 young, 12 middle-aged, and 16 older sedentary males.	EPC telomere length	Lower EPC telomere length in older vs. middle-aged and younger males.
Kushner et al., 2010 [57]	17 young and 20 older males.	Stimulated release of EPC-derived pro-angiogenic cytokines and growth factors	Lower release of G-CSF from EPCs from older vs. younger subjects.

EPC- Endothelial Progenitor Cells, eNOS- endothelial nitric oxide synthase, EC-CFU- Endothelial Cell Colony-Forming Units. CXCR4- C-X-C Chemokine Receptor 4.