Overexpression of inhibits myogenesis by regulating the expression of myogenic regulatory factors.

Syndecan-4, a type of heparan sulfate proteoglycan, plays an important role in muscle development, regeneration, and maintenance. Although the important effects of on the regulation of myogenesis in mice, turkeys, and bovines have been consistently reported, the molecular mechanisms of in myogenesis are not well understood. In this study, the role of in regulating myogenesis was investigated in quail myoblast (QM7) cells, which constituting a quail myogenic cell line. Overexpression of inhibited myogenesis, resulting in reduced myoblast fusion and shorter myotubes than in the control group. Therefore, the cells overexpressing showed a smaller total myotube area than did the control cells. Furthermore, these cells had lesser myosin heavy chain proteins, suggesting that muscle differentiation is inhibited by . To investigate the inhibitory effect of on myogenic differentiation, the mRNA expression levels in several genes known to regulate myoblast proliferation and differentiation were compared. Myogenic regulatory factors, including , , and , showed significantly different expressions between the groups during myogenesis. , a negative regulator of muscle growth, showed significantly higher expression on day 4 in cells overexpressing . In conclusion, could delay and inhibit muscle differentiation by regulating the expression levels of myogenic factors and muscle growth regulator in quail myocytes. This study provides valuable information regarding the role of in myogenesis, which may aid in improving the production of poultry meat.