Relationship between muscle cell proliferation and growth factors in pejerrey during starvation

SIMO, I.; SCIARA A.A.; ARRANZ S.E.

Rosario

Congreso; L Congreso de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2014

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

Insulin-like growth factors (IGFs) are key regulatory elements for growth and maintenance of skeletal muscle. Myostatin (MSTN) negatively regulates skeletal muscle growth, through the inhibition of myoblast cell cycle progression and the activation of p21 and MyoD for terminal differentiation. Our previous data indicate that IGF-1and MSTN are down regulated in muscle of pejerrey (Odontesthes bonariensis) during starving conditions. In order to gain insight into the relationship between expression of growth factors and cell proliferation, 300± 20 mg juveniles pejerrey were starved for 2 weeks (starved group) or fed twice a day (control group). On day 7 and 10 of treatment fishes received an intra peritoneal injection of 5-ethynyl-2´-deoxyuridine (EdU) in order to track and label proliferative muscle cells. Fluorescent EdU labeled cells were analysed in transverse cryostat muscle sections. Our results indicate that proliferation of muscle progenitor cells, although significantly lower, continued during starved periods. Interestingly lower proliferation levels did not correlate with higher expression levels of MSTN. This suggests that MSTN could modulate muscle cell proliferation only under food availability.