Fig. 1.
Transdifferentiation of C2C12 cells from myoblasts to osteoblasts induced by rhBMP-2. The cells were cultured for 4 (a, c) or 14 days (b, d), without (a, b) or with 100 ng/ml of rhBMP-2 (c, d) and observed (X 40). Arrowheads indicate the presence of myotubes. At 4 days of treatment, cell shape changed to osteoblast-like round shape (c). At day 14, typical myotubes were well formed without rhBMP-2 treatment (b) whereas cell/matrices layer was clearly formed with the treatment (d). At day 4, ALP activity was increased with rhBMP-2 treatment in a dose dependent manner (e). mRNA expression of myogenic and osteogenic genes with or without rhBMP-2 treatment at various time points analyzed by real-time PCR (f–j). Note that osteogenic genes were upregulated (h–j) whereas myogenic genes suppressed (f,g) with time.