Regulation of IGF-I, IGFBP-4 and IGFBP-5 gene expression by loading in mouse skeletal muscle

FEBS Lett. 1999 Nov 19;461(3):263-7. doi: 10.1016/s0014-5793(99)01469-6.

Abstract

Gene expression of IGF-I, IGFBP-4 and IGFBP-5 was studied in hindhimb skeletal muscle of mice, which were either overloaded or unloaded for 8 days. Overloading induced a 15% hypertrophy in soleus muscle associated with a 60% increase of IGF-I transcript levels and a doubling of IGFBP-4 mRNA levels. IGFBP-5 mRNA levels were decreased to one third of the control value. Changes in IGFBPs mRNA always preceded changes in IGF-I gene expression. Unloading by hindlimb suspension resulted in atrophy of soleus muscle (20%) and phenotype change towards the fast type associated with a transient decrease of IGF-I mRNA (30%) and a sustained increase (x2) of IGFBP-5 transcript. These alterations in IGFBPs expression, in unloaded or overloaded soleus, suggest that they may play a role in skeletal muscle adaptation to changes in loading.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / genetics
  • Animals
  • Gene Expression Regulation*
  • Insulin-Like Growth Factor Binding Protein 4 / biosynthesis*
  • Insulin-Like Growth Factor Binding Protein 4 / genetics
  • Insulin-Like Growth Factor Binding Protein 5 / biosynthesis*
  • Insulin-Like Growth Factor Binding Protein 5 / genetics
  • Insulin-Like Growth Factor I / biosynthesis*
  • Insulin-Like Growth Factor I / genetics
  • Male
  • Mice
  • Mice, Inbred Strains
  • Muscle Proteins / biosynthesis*
  • Muscle Proteins / genetics
  • Prostheses and Implants
  • Weight-Bearing*

Substances

  • Insulin-Like Growth Factor Binding Protein 4
  • Insulin-Like Growth Factor Binding Protein 5
  • Muscle Proteins
  • Insulin-Like Growth Factor I