Extrinsic Mechano Growth Factor Induces Cell Proliferation and MGF mRNA Expression in Rat Skeletal Muscle Satellite Cells in Vitro

Objective Mechano Growth Factor (MGF) is one kind of autocrine growth factor sensitive to mechanical stimulus. It plays a significant role between mechanical stimulation and gene expression by activating satellite cell proliferation. The purpose of the study is to investigate the effects of supplements of MGF on the proliferation of skeletal muscle satellite cells. Methods Satellite cells were isolated from SD rat hind limb muscles with two-steps enzyme digestion. After cell synchronization, skeletal muscle satellite cells cultured for 96 hours, and different concentrations of MGF (0 ng/ml, 25 ng/ml, 50 ng/ml, 100 ng/ml and 150 ng/ml) were added to culture medium, respectively. The proliferation of satellite cells and the total protein content were detected. Total RNA was extracted from the cells samples and RT-PCR detection was used to evaluate mRNA MGF relative expression. Results Compared with 0 ng/ml MGF, OD values in 25 ng/ml and 50 ng/ml group were significantly increased at each time point (P 0.05), From 24 h to 96 h, OD value in 25 ng/ml group was highly significant (P 0.01), and OD value in 50 ng/ml group was also a highly significant increase at 24 h to 72 h (P 0.01); Compared with the control group, the expression of MGF mRNA in 25 ng/ml and 50 ng/ml groups were significantly increased (P 0.05), but other treatment groups have no significant difference (P 0.05); the total protein content in 25 ng/ml and 50 ng/ml group were significantly increased compared with 0 ng/ml group (P 0.05). Conclusion The appropriate concentration of MGF has role in promoting muscle satellite cell proliferation, between 25 ng/ml and 50 ng/ml concentration have a strong effect on the proliferation, but difference in time course.