Fig. 7

Hypoxic preconditioning of endothelial colony-forming cells (ECFCs) enhances functional recovery after limb ischemia. a Improvements in blood flow recovery were evaluated using LDPI analysis in the ischemic limbs of 8-week-old Balb/C nude mice injected with phosphate-buffered saline (PBS), nor-ECFCs, and hypo-ECFCs at 0, 4, 9, 18, and 28 days post-surgery. b The ratio of blood perfusion (blood flow of the left ischemic limb/blood flow of the right non-ischemic limb) was measured in the three groups. Values represent means ± SD. **P < 0.01 vs. PBS group; ^## P < 0.01 vs. nor-ECFCs. c, e Representative images of mouse-specific CD31⁺ and human-specific CD31⁺ tissue at 28 days after transplantation of nor-ECFC or hypo-ECFC into hindlimb ischemia (scale bar: 50 μm; n = 10). g Representative images of arteriole structures (α-SMA staining for arterioles, red fluorescence)-positive tissue at 28 days after transplantation of nor-ECFC or hypo-ECFC into hindlimb ischemia (scale bar: 50 μm; n = 10). Quantification (d, f, h) represents cell numbers analyzed per high-power field (HPF). Values represent means ± SD. **P < 0.01 vs. nor-ECFCs; ^## P < 0.01 vs. hypo-ECFCs. i H&E staining was used to produce histological images of tissue 28 days after transplantation of nor-ECFCs or hypo-ECFCs into hindlimb ischemia