Fig. 4

Fluorescence microscopy of MyHC2 in co-cultures. A positive staining of MyHC2, a muscle-specific major contractile protein, in MSC and Mb co-cultures under HGF stimulation for 7 d (a) and 14 d (b). Merge of DAPI (blue, nuclear staining), GFP (green, transduced MSC) and MyHC2 (red, with Alexa fluor 594 as secondary antibody). a The beginning formation of multinucleated cells could be observed under HGF stimulation. MSCs show positive expression of MyHC2 (arrows). Scale bars represent 20 μm. Magnification 400x. b The formation of multinucleated cells could be observed under HGF stimulation. It seems that MSCs are involved in the formation of multinucleated cells (arrows). Scale bars represent 50 μm. Magnification 200x