Mini-dystrophins reduce the terminal myogenic differentiation of human Duchenne muscular dystrophy (DMD) muscle cells (A), and this is reversed by the knockdown of dystrophin expression using siRNAs (B). Mini-dystrophin GFP+ cells were induced to undergo myogenic differentiation for 7 days, and the fusion index (FI) of each experimental group showed that both ΔR3R13–GFP and ΔH2R23–GFP transduced cells have a reduced fusion index compared to non-transduced cells (A), scale bar = 25 µm. To determine whether the effect of mini-dystrophin on myogenic differentiation is reversible, ΔH2R23–GFP cells were transfected with one of the two different dystrophin siRNAs (4155 and 4156), and then induced to undergo myogenic differentiation for 7 days. Western blot showed that after SiRNA transfection, the dystrophin ΔH2R23–GFP expression was reduced and myosin heavy chain increased in cells transfected with siRNA 4155, but not in cells transfected with siRNA 4156, (B). NT: non-transfected SFFV–ΔH2R23–GFP cells; ConSi, 4155, 4156: SFFV–ΔH2R23–GFP cells transfected with control siRNA or dystrophin siRNAs 4155 or 4156, respectively. * p < 0.05; ** p < 0.01.