Fig. 4
Low levels of L-periaxin were required for Ezrin to activate MyoG/MEF2C-mediated myoblast differentiation/fusion. A Typical image of MyHC, MyoG or MEF2c staining in differentiated C2C12 myoblasts with overexpression or knockdown of Ezrin with or without Ad-Periaxin or Ad-shPeriaxin at 6 days of differentiation. Red fluorescence indicates MyHC, MyoG or MEF2c; DAPI indicates the nucleus. B Ad-Ezrin, but not Ad-Periaxin, increased the numbers of MyHC + myotubes with 5+ myoblast fusion, as determined by a quantitative assay of myotubes, and the Ad-Ezrin effect was enhanced by knockdown of L-periaxin by shRNA in myoblasts. C Ad-Ezrin or Ad-shPeriaxin increased myotube size in MyHC-positive myotubes with 5+ myoblast fusion, while Ad-shEzrin or Ad-Periaxin decreased them as analyzed by quantitative assay of the ratio in myotube size normalized to the Ad-null group. Ad-shPeriaxin enhanced the effect of Ad-Ezrin on myotube size, while Ad-Periaxin further deteriorated the inhibitory effect of Ad-shEzrin on myotube size. D, E Quantitative assay for MEF2c + or MyoG + nuclei numbers in the above images. Three independent experiments were performed, n = 3, *P < 0.05 vs. Ad-Null; #P < 0.05 vs. Ad-Null; &P < 0.05 vs. Ad-Null; $P < 0.05 vs. Ad-Null; @P < 0.05 vs. Ad-Ezrin; ^P < 0.05 vs. Ad-shEzrin