Sphingosine-1-phosphate Mediates epidermal growth factor-induced muscle satellite cell activation.

Sphingosine-1-phosphate Mediates epidermal growth factor-induced muscle satellite cell activation. Exp Cell Res. 2014 Jun 21; Authors: Nagata Y, Ohashi K, Wada E, Yuasa Y, Shiozuka M, Nonomura Y, Matsuda R Abstract Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P recep...
Source: Experimental Cell Research - Category: Cytology Authors: Tags: Exp Cell Res Source Type: research