Neuroprotective effects of short peptides derived from the Insulin-like growth factor 1

Neurochem Int. 2007 Dec;51(8):451-8. doi: 10.1016/j.neuint.2007.04.030. Epub 2007 May 16.


Insulin-like growth factor I (IGF-1) is a peptide synthesized in response to growth hormone stimulation. While most of the circulating IGF-1 comes from the liver, it can also be produced in other tissues and both its expression and processing undergo tissue-specific regulation. The predominant form, IGF-1Ea is a circulating factor while two others, IGF-1Eb and IGF-1Ec (MGF), are mostly expressed in different tissues or in response to various stimuli and show some preferences with respect to the signal transduction pathways they activate. In skeletal muscle specific forms of IGF-1 play a role in development and growth and in addition to these physiological roles IGF-1 functions in the damaged muscle. IGF-1 is also important for the developing and adult brain and can reduce neuronal death caused by different types of injuries. Like many other peptide hormones IGF-1 originates from a precursor pro-hormone that undergoes extensive post-translational modifications. Processing liberates the mature peptide, which acts via the specific IGF-1 receptor but additional short peptides can arise from both N- and C-termini of various IGF-1 isoforms. These derivatives function as autonomous biologically active peptides and extremely potent neuroprotective agents. Their biological effects are independent of the activation of the IGF-1 receptor. Unfortunately, little is known about their mechanism(s) of action. Likewise, the existence of the endogenous production and wider biological effects of these short peptides are uncertain. However, considering the difference in the modes of action it might be possible to dissociate the unwanted and potentially dangerous mitogenic activity of the full-length IGF-1 exerted via its receptor from the neuroprotective effects of short derivatives mediated through different pathways. Such small molecules show good penetration through the blood brain barrier, can be inexpensively manufactured and modified to increase their stability. Therefore, they are good candidates for development into a neuroprotective therapeutic modality.

Publication types

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

MeSH terms

  • Animals
  • Blood-Brain Barrier / drug effects*
  • Blood-Brain Barrier / metabolism
  • Brain Diseases / drug therapy
  • Humans
  • Insulin-Like Growth Factor I / analogs & derivatives*
  • Insulin-Like Growth Factor I / biosynthesis
  • Insulin-Like Growth Factor I / pharmacology*
  • Mitogens / adverse effects
  • Neuroprotective Agents / pharmacokinetics
  • Neuroprotective Agents / pharmacology*
  • Neuroprotective Agents / therapeutic use
  • Peptides / pharmacokinetics
  • Peptides / pharmacology*
  • Peptides / therapeutic use
  • Protein Structure, Tertiary / drug effects
  • Protein Structure, Tertiary / physiology
  • Receptor, IGF Type 1 / agonists
  • Receptor, IGF Type 1 / metabolism


  • Mitogens
  • Neuroprotective Agents
  • Peptides
  • Insulin-Like Growth Factor I
  • Receptor, IGF Type 1