Figure 5. Activation of macrophages leads to fAd proteolysis and gAd production.

A) Activated murine macrophages secrete gAd. RAW 294.7 Macrophages are activated by incubation for 24 h with free-serum medium contained LPS (10 ng/ml) and IFN-γ (50 U/ml). Culture media were concentrated 20-fold and analysed by anti-adiponectin immunoblot. Recombinant fAd and gAd were used in parallel as markers. B) Conditioned media from activated macrophages induces the migration of mSAT towards differentiated myotubes. After activation, murine RAW 294.7 macrophages were treated with serum-free medium for 24 hours to remove LPS and INF-γ and then the corresponding conditioned media were used for mSAT migration assay towards myotubes. mSAT were serum deprived overnight and then seeded in the upper chamber of the Boyden assay in free-serum medium with or without exogenous fAd (1 µg/ml) or gAd (1 µg/ml) or in resting or activated macrophage-conditioned media. Four days differentiated C2C12 myotubes were cultured in the lower chamber and used as chemoattractant. *p<0,001 vs control. C) Adiponectin attracts macrophages towards satellite cells. Murine RAW 294.7 macrophages were serum deprived overnight and then seeded in the upper chamber of a Boyden assay in serum free medium. mSAT were cultured in the lower chamber in free serum medium with or without fAd (1 µg/ml) or gAd (1 µg/ml) and used as chemoattractant. Migrated macrophages were detected after 16 hours by hematoxylin-eosin staining. Images are representative of four independent experiments with similar results. *p<0,001 and ♦p<0,01 vs control.