Insulin-like growth factor I (IGF-1) Ec/Mechano Growth factor--a splice variant of IGF-1 within the growth plate

PLoS One. 2013 Oct 11;8(10):e76133. doi: 10.1371/journal.pone.0076133. eCollection 2013.

Abstract

Human insulin-like growth factor 1 Ec (IGF-1Ec), also called mechano growth factor (MGF), is a splice variant of insulin-like growth factor 1 (IGF-1), which has been shown in vitro as well as in vivo to induce growth and hypertrophy in mechanically stimulated or damaged muscle. Growth, hypertrophy and responses to mechanical stimulation are important reactions of cartilaginous tissues, especially those in growth plates. Therefore, we wanted to ascertain if MGF is expressed in growth plate cartilage and if it influences proliferation of chondrocytes, as it does in musculoskeletal tissues. MGF expression was analyzed in growth plate and control tissue samples from piglets aged 3 to 6 weeks. Furthermore, growth plate chondrocyte cell culture was used to evaluate the effects of the MGF peptide on proliferation. We showed that MGF is expressed in considerable amounts in the tissues evaluated. We found the MGF peptide to be primarily located in the cytoplasm, and in some instances, it was also found in the nucleus of the cells. Addition of MGF peptides was not associated with growth plate chondrocyte proliferation.

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Animals
  • Cell Nucleus / metabolism
  • Cell Proliferation / drug effects
  • Chondrocytes / cytology
  • Chondrocytes / drug effects
  • Chondrocytes / metabolism*
  • Cytosol / metabolism
  • Gene Expression
  • Growth Plate / cytology
  • Growth Plate / drug effects
  • Growth Plate / metabolism*
  • Humans
  • Insulin-Like Growth Factor I / genetics*
  • Insulin-Like Growth Factor I / metabolism
  • Mechanotransduction, Cellular
  • Molecular Sequence Data
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / metabolism
  • Peptides / genetics*
  • Peptides / metabolism
  • Peptides / pharmacology
  • Primary Cell Culture
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Swine

Substances

  • Peptides
  • RNA, Messenger
  • Insulin-Like Growth Factor I

Grants and funding

The authors have no support or funding to report.