strong neuroprotective effect of the autonomous C-terminal peptide of IGF-1 Ec (MGF) in brain ischemia

• Published in: The FASEB journal Vol. 19; no. 13; pp. 1896 - 1898
• Main Authors: Dłużniewska, Joanna, Sarnowska, Anna, Beręsewicz, Małgorzata, Johnson, Ian, Srai, Surjit K. S, Ramesh, Bala, Goldspink, Geoffrey, Górecki, Dariusz C, Zabłocka, Barbara
• Format: Journal Article
• Language: English
• Published: United States 01.11.2005
• Subjects: Alternative Splicing; Amino Acid Sequence; Animals; Blotting, Western; Brain - pathology; Brain Ischemia - pathology; Exons; Gerbillinae; Hippocampus - metabolism; Hippocampus - pathology; Immunoblotting; Immunohistochemistry; In Situ Hybridization; Insulin-Like Growth Factor I - chemistry; Insulin-Like Growth Factor I - metabolism; Insulin-Like Growth Factor I - pharmacology; Ischemia; Male; Microscopy, Fluorescence; Models, Biological; Molecular Sequence Data; Muscle, Skeletal - metabolism; Neurodegenerative Diseases - pathology; Neurons - metabolism; Neuroprotective Agents - pharmacology; Peptides - chemistry; Protein Isoforms; Protein Structure, Tertiary; Recombinant Proteins - chemistry; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; Species Specificity; Time Factors
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fj.05-3786fje

The ischemic stroke is the third leading cause of death in developed countries. The C-terminal peptide of mechano-growth factor (MGF), an alternatively spliced variant of insulin-like growth factor 1 (IGF-1), was found to function independently from the rest of the molecule and showed a neuroprotective effect in vivo and in vitro. In vivo, in a gerbil model of transient brain ischemia, treatment with the synthetic MGF C-terminal peptide provided very significant protection to the vulnerable neurons. In the same model, ischemia evoked increased expression of endogenous MGF in the ischemia-resistant hippocampal neurons, suggesting that the endogenous MGF might have an important neuroprotective function. In an in vitro organotypic hippocampal culture model of neurodegeneration, the synthetic peptide was as potent as the full-length IGF-1 while its effect lasted significantly longer than that of recombinant IGF-1. While two peptides showed an additive effect, the neuroprotective action of the C-terminal MGF was independent from the IGF-1 receptor, indicating a new mode of action for this molecule. Although MGF is known for its regenerative capability in skeletal muscle, our findings demonstrate for the first time a neuroprotective role against ischemia for this specific IGF-1 isoform. Therefore, the C-terminal MGF peptide has a potential to be developed into a therapeutic modality for the prevention of neuronal damage.