(A–D) α-SMA (red) staining at 21 days in adductor of vehicle- (A), mMAPC-U– (B), mMAPC-U2– (C), or hMAPC-U–treated mice (D). Overexposure in the DAPI channel was used to reveal muscle tissue. (E and F) Laser Doppler measurements (E) in left legs (expressed as % improvement versus pretransplant [day +5] and relative to the nonligated right leg); and treadmill endurance test (F) measuring hind limb function (expressed as % of pretransplant performance [day +5]) at several time points after (+) ligation of vehicle- (red), mMAPC-U– (black), mMAPC-U2– (gray), or hMAPC-U–treated mice (blue). (G–J) Sirius red–stained cross sections of gastrocnemius muscle 3 weeks after transplantation of vehicle- (G), mMAPC-U– (H), mMAPC-U2– (I), or hMAPC-U–injected (J) animals. (K) Quantitative analysis of α-SMA (in adductor), viability (TTC), fibrosis (Sirius red), and myogenesis (desmin) staining (all in gastrocnemius), expressed as percent positive staining per muscle area in vehicle- (red), mMAPC-U– (black), mMAPC-U2– (gray), or hMAPC-U–treated mice (blue). All analyses were performed on 6–12 mice per group. *P < 0.05 versus vehicle for each corresponding time point; ^†P = 0.05 versus vehicle; ^#P = 0.07 versus vehicle. Scale bars: 250 μm (A–D) and 62.5 μm (G–J).