Mechano growth factor (MGF) promotes proliferation and inhibits differentiation of porcine satellite cells (PSCs) by down-regulation of key myogenic transcriptional factors

• DOI: 10.1007/s11010-012-1413-9
• Publication Date: 2012-08-08T15:11:48Z
• Authors: Li-Li Qin; Xiao-Kui Li; Jian Xu; De-Lin Mo; Xiong Tong; Zhi-Cheng Pan; Jia-Qi Li; Yao-Sheng Chen; Zhe Zhang; Chong Wang; Qiao-Ming Long
• Keywords: Cyclin-Dependent Kinase Inhibitor p21; 0301 basic medicine; Satellite Cells, Skeletal Muscle; Cell Cycle; Sus scrofa; Down-Regulation; Cell Differentiation; Muscle Development; 03 medical and health sciences; Animals; Humans; Insulin-Like Growth Factor I; Cells, Cultured; Cell Proliferation; MyoD Protein; Transcription Factors

Porcine satellite cells represent an ideal model system for studying the cellular and molecular basis regulating myogenic stem cell proliferation and differentiation and for exploring the experimental conditions for myoblast transplantation. Here, we investigated the effects of mechano growth factor (MGF), a spliced variant of the IGF-1 gene, on porcine satellite cells. We show that MGF potently stimulated proliferation while inhibited differentiation of porcine satellite cells. MGF-treatment acutely down-regulates the expression of myogenic determination factor (MyoD) and the cyclin-dependent kinase inhibitor p21. MGF-treatment also markedly reduced the overall expression of cyclin B1 and key factors of the myogenic regulatory and myocyte enhancer families, including Myogenein and MEF2A. Taken together, the gene expression data from MGF-treated porcine satellite cells are in favor of a molecular model in which MGF inhibits porcine satellite cell differentiation by down-regulating either the activity or expression of MyoD, which, in turn, suppresses the expression of key genes required for cell cycle progression and differentiation, such as p21, Myogenin, and MEF2. Overall, our findings are in support of the previous suggestion that MGF may be used in vivo and in vitro to promote proliferation of myogenic stem cells to prevent and treat age-related muscle degenerative diseases.