Interleukin-15: A Novel Anabolic Cytokine for Skeletal Muscle

Endocrinology. 1995 Aug;136(8):3669-72. doi: 10.1210/endo.136.8.7628408.

Abstract

Interleukin-15 (IL-15) is a recently discovered growth factor which is highly expressed in skeletal muscle. In order to determine a functional role for IL-15 in skeletal myogenesis, the effects of IL-15 on myoblast proliferation and muscle-specific myosin heavy chain (MHC) expression were analyzed using the mouse C2 skeletal myogenic cell line and primary fetal bovine skeletal myogenic cultures. IL-15 had no effect on [3H]thymidine incorporation, nor on the rate of myoblast differentiation, assessed by anti-MHC immunocytochemical staining, in either type of culture. However, Western blot analyses revealed that IL-15 used at concentrations of 10 or 100 ng/ml increased MHC accumulation five-fold in C2 myoblast cultures and 2.5-fold in primary bovine myogenic cultures. Moreover, C2 myotubes formed in the presence of IL-15 appeared larger than controls. These findings indicate IL-15 can stimulate differentiated myocytes and muscle fibers to accumulate increased amounts of contractile proteins. Well-fused primary bovine myogenic cultures treated with the mitotic inhibitor aphidicolin, then administered IL-15 and/or the anabolic growth factor insulin-like growth factor-I (IGF-I), were analyzed for MHC accumulation using Western blots. IL-15 used at 10 ng/ml doubled MHC accumulation and was as effective as IGF-I used at 10 or 100 ng/ml. IL-15 and IGF-I used together increased MHC accumulation close to five-fold, indicating these two factors can act additively on muscle fibers. These findings indicate IL-15 affects parameters associated with skeletal muscle fiber hypertrophy, and suggest that IL-15 may be a novel anabolic agent to increase skeletal muscle mass.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Cell Differentiation
  • Cell Line
  • Cytokines / physiology*
  • Haplorhini
  • Insulin-Like Growth Factor I / pharmacology
  • Interleukin-15
  • Interleukins / physiology*
  • Mice
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / physiology*
  • Myosins / metabolism
  • Recombinant Proteins

Substances

  • Cytokines
  • Interleukin-15
  • Interleukins
  • Recombinant Proteins
  • Insulin-Like Growth Factor I
  • Myosins