Fig. 2

Transplantation of MSC^GDF11 promoted angiogenesis and muscle regeneration in vivo. A Representative LDPI shows dynamic changes of blood perfusion in ischemic limbs at indicated time points. Different colors represent the changes in blood flow. B The blood flow of the lower limbs was quantitatively analyzed as the ratio of ischemic (right) side to nonischemic (left) side (n = 5–8 in each group). n = 5 for Sham, 7 for PBS, 8 for MSCs^Vector, and 8 for MSCs^GDF11. *p < 0.05 MSCs^Vector versus MSCs^GDF11. These had been repeated twice. C Representative hematoxylin and eosin-stained sections of ischemic muscles from each group at 14 days. Myocytes with centralized nuclei were considered as regenerating myofibers. Scale bar: 25 μm. D Quantification of regenerating myofibers by counting the myocytes with centralized nuclei as a percentage of total myocytes in a field. n = 5 for Sham, 7 for PBS, 8 for MSCs^Vector, and 8 for MSCs^GDF11. E Immunofluorescent staining of CD31 and smooth muscle α-actin (α-SMA) in cryosections of ischemic muscles obtained from mice at day 14 after surgery. Endothelial cells were stained with Ab against CD31, and smooth muscle cells were stained with Ab against α-SMA. Scale bars: 100 μm (n = 5 in sham group; n = 7 in PBS group, and other group n = 8). F Quantification of CD31 positive ECs. G Quantification of α-SMA positive arteriole density. *p < 0.05; **p < 0.01 and ***p < 0.001