[Proliferative effect of basic fibroblast growth factor and epidermal growth factor on muscle derived stem cells]

To explore the effect of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) on the growth of muscle derived stem cells (MDSCs).

MDSCs were isolated from hindlimb muscle of 15 new born Kunming mice through serial preplates. 2% fetal bovine serum-containing DMEM was used to induce MDSCs to differentiate into skeletal muscle lineage. The expressions of stem cell marker Sca-1 and skeletal muscle cell marker alpha-Sarcomeric actin were examined by immunocytochemistry. The effect of bFGF and EGF on the proliferation of MDSCs was determined by MTT colorimetric microassay. The solo effect of bFGF or EGF at different concentrations (6.25, 12.50, 25.00, 50.00, and 100.00 ng/ml) was examined at 96 h and the combined effect (100.00 ng/ml) was examined at 24, 48, 72 and 96 h.

MDSCs were successfully isolated from the hindlimb of neonatal mice. Over 90% of MDSCs showed Sca-1 positive immunoreactivity. MDSCs could give rise to alpha-Sarcomeric actin positive myotubes in differentiation cultures. The proliferative effect of bFGF and EGF on MDSCs increased with the elevated concentration. bFGF began to show significant proliferative effect at 12.50 ng/ml (P<0.05). The effect increased significantly when the concentration reached 25.00 ng/ml from 12.50 ng/ml (P < 0.01) and reached a saturation point. The effect at 50.00 ng/ml or 100.00 ng/ml showed no significant increase when compared with that at 25.00 ng/ml. EGF had a similar effect to bFGF except that the saturation concentration was 50.00 ng/ml. EGF showed significant effect at 72 h and bFGF at 96 h (P<0.01). When they were applied together, significant effect was shown at 24 h (P<0.01) and much higher effect was observed at 48, 72 and 96 h (P<0.05).

Both bFGF and EGF can promote the proliferation of MDSCs. The combined application reacts faster and stronger.