Figure 1: Wnt7a-CT induces hypertrophy in differentiated myotubes and myofibres.

(a) Schematic showing the different Wnt7a variants used. SP: signal peptide, the Wnt7a full-length (FL) protein is palmitoylated on C73 and S206. (b) C2C12 cells were transiently transfected with an expression plasmid for Wnt7a-CT, Wnt7a-FL or a control plasmid and differentiated for 5 days, n=4, **P<0.01. (c) C2C12 cells were transiently transfected with Wnt7a-CT, Wnt7a-FL or a control plasmid and differentiated for 5 days. Staining for MHC (myosin heavy chain, in green) marks differentiated cells, nuclei are counterstained with Dapi (in blue). Scale bar: 20 μm. (d) Electroporation of a Wnt7a-CT, Wnt7a-FL or control plasmid into the TA muscle of C57/BL6 mice resulted in increased muscle wet weight in muscles electroporated with the Wnt7a-CT and Wnt7a-FL plasmids 2 weeks after electroporation, n=4, *P<0.05. The weight of the contralateral leg is shown as grey bars. (e) Electroporation of the TA muscle with a Wnt7a-CT and a Wnt7a-FL expression plasmid resulted in increased fibre calibre, n=4, ***P<0.001. (f) Representative images of immunostained sections of TA muscles as in d and e for laminin (in green); nuclei are counterstained with Dapi (in blue). Scale bar: 100 μm. (g) Injection of Wnt7a-CT or Wnt7a-FL protein into the TA muscle of C57/BL6 mice resulted in increased muscle wet weight in muscles 2 weeks after injection, n=4, *P<0.05. The weight of the contralateral leg is shown as grey bars. (h) Injection of the TA muscle with Wnt7a-CT and Wnt7a-FL proteins resulted in increased fibre calibre, n=4, **P<0.01. (i) Representative images of immunostained sections of TA muscles as in g and h for laminin (in green); nuclei are counterstained with Dapi (in blue). Scale bar: 100 μm. All P-values were calculated using a two-tailed Student’s t-test. All data are expressed as mean±s.e.m.