Figure 1

Muscle-derived mesenchymal stem/stromal cell (mMSC) appearance, proliferation, and myogenic gene expression. mMSCs were plated on laminin (LAM) or collagen (COL) and were either exposed to mechanical strain or remained unstrained. Representative images of mMSCs exposed to the various substrates (A). mMSC quantity as determined by hemocytometer 48 hours post-strain with non-strained cells serving as controls (n = 6 per group) (B). Gene expression of the myogenic regulatory factors Myf5 (C), MyoD (D), and Myogenin (E) 3 hours post-strain (n = 3 per group). Pax7 mRNA was not reliably detected in any group. Fold change is relative to LAM no strain. Data are presented as mean ± standard error of the mean. **P <0.01 versus LAM (main effect for substrate).