Fig. 4

Rescue of DMD knock down by micro-dystrophin in 3D-tissue-engineered-skeletal muscle. A Cartoon of endogenous DMD and micro-dystrophin mRNA. The subset of DMD exons used to generate micro-dystrophin is indicated in orange. RT-qPCR primers that are specific for endogenous DMD (primer set 1) or that recognize both endogenous DMD and micro-dystrophin (primer set 2) are indicated. B RT-qPCR analysis of endogenous DMD and micro-dystrophin mRNAs. C Force-generating capacity (twitch stimulation) and maximum force-generating capacity (tetanic stimulation) of 3D-TESMs after 7 days of myogenesis. Data are represented as mean ± SD derived from six independent 3D-TESMs. D Representative images of whole-mount immunofluorescent stainings of experimental conditions from B and C. Red, anti-titin antibody. Green, GFP. Blue, nuclei stained with Hoechst. E Myofiber diameter of 3D-TESMs (n = 40–60 myofibers for each condition). F Myofiber alignment of 3D-TESMs. Myofiber alignment was measured using Δ of the angle of each myofiber relative to the perpendicular axis of the 3D-TESM (n = 40–60 fibers per condition). Statistical significance is indicated relative to the DMD knock down (B and C) or non-targeting control (E and F). For F, significance was calculated using the distribution of the variance. ns, not significant, *p < 0.05, **p < 0.01. #Indicates the conditions where the analyses were prevented by the poor quality of the 3D-TESM tissues