Fig. 3

Effect of MSCs on myofiber regeneration. a Quantification of muscle fiber diameter, densities (calculated by normalizing the total number of fibers to section area), and number of regenerated fibers (identified by their central nuclei). b Immunostaining of the slow- and fast-twitch myofibers. c Percentage of each fiber type in nonirradiated skeletal muscle (control group), irradiated skeletal muscle on the day of surgery (Irr D100 group), and 12 months after flap surgery with (flap-MSC group) and without (flap group) MSC treatment. Scale bar 100 μm. d Real-time-PCR of fast myosin heavy chain 2 and slow myosin heavy chain 7. Data are expressed relative to control skeletal muscle and normalized to GAPDH. Results are expressed as means ± SEM. P values were calculated by ANOVA with Bonferroni correction, *P < 0.05; **P < 0.01; ***P < 0.001 compared with nonirradiated skeletal muscle; ^#P < 0.05; ^##P < 0.01; ^###P < 0.001 compared with irradiated-untreated controls