Figure 4.

Effect of IL-15 in muscle atrophy and proteolysis in mouse myoblast (C2C12) cell and in limb muscle of sepsis animal model. (A) Cathepsin L enzyme activity in C2C12 cells when incubated with dexamethasone (100 nM/mL), LPS (10µg/mL), or TNF-α (10µg/mL), in the presence or absence of IL-15 (20µg/mL). The activity of cathepsin L was found to be decreased in C2C12 cells co-stimulated with IL-15. (B) The cathepsin L enzyme activity in TA and EDL muscle lysates of mice pretreated with IL-15 (10µg/kg), prior to the induction of sepsis by CLP was significantly decreases as compared to those obtained from mice that had not been pretreated (p<0.05). CLP: cecal ligation and puncture; Dexa: dexamethasone; EDL: extensor digitorum longus; IL-15: interleukin-15; LPS: lipopolysaccharide; TA: tibialis anterior; TNF: tumor necrosis factor.