Figure 3.

Myostatin genetic inactivation blocks the myogenic differentiation capacity of MDSCs. (A-C) Representative pictures of confluent MDSCs from the WT MDSCs and Mst KOs maintained for 2 weeks in myogenic medium and subjected to immunocytochemistry for MHC II to detect differentiation into polynucleated myotubes (magnifications as indicated). (D) Blue/red merge of confluent MDSCs in myogenic medium that were labeled with DAPI and submitted to immunofluorescent detection of MHC (200×); (E) Western blot for MHC II (210 kDa) in the confluent cultures undergoing myogenesis, and (F) for MyoD (45 kDa) in the nonconfluent cultures in nonmyogenic medium. MDSC, muscle-derived stem cell; WT, wild type; Mst KO, myostatin knockout; MHC, myosin heavy chain; DAPI: 4', 6-diaminido-phenylindole.