Comparable frequencies but lower ROS levels in BM ECs from young
donors
To clarify whether BM EC frequencies differ in young, middle-aged and
old individuals, we measured BM ECs
(CD34+CD309+CD133+)
by flow cytometry. Fig. 1 shows the gating strategy of BM ECs and the
percentages as well as intracellular ROS levels of BM ECs among the
three age groups. The percentages of primary BM ECs were comparable in
the three groups (Fig. 1B, 0.12% ± 0.01% vs. 0.11% ± 0.01%, P
= 0.98; 0.12% ± 0.01% vs. 0.11% ± 0.009%, P = 0.74), whereas
the ROS levels in BM ECs from young donors were significantly lower than
those from middle-aged donors (Fig. 1C, 1661 ± 259 vs. 2462 ± 253,P =0.02) and old donors (Fig. 1C, 1661 ± 259 vs. 2715 ± 315,P =0.005).