Different levels of neuroprotection by two insulin-like growth factor-I splice variants.
Aperghis. Michael M; Johnson. Ian P IP; Cannon. John J; Yang. Shi-Yu SY; Goldspink. Geoffrey G
Key Findings
- Injecting the MGF splice variant into muscle before nerve damage protected about 80‑90% of motor neurons in rats.
- The liver‑type IGF‑1 (IGF‑IEa) was far less protective when delivered the same way.
- Local (peripheral) delivery of IGF‑1 variants appears more effective for neuron survival than systemic IGF‑I.
Practical Outcomes
- For biohackers, the take‑away is that muscle‑derived IGF‑1 forms like MGF might be a promising route for neuro‑protection, but the current evidence is limited to gene‑plasmid injections in rats. Until safe human delivery methods are developed, the finding is more a hint for future research than a ready‑to‑use protocol.
Summary
In rats, delivering the muscle‑derived IGF‑1 splice form called MGF directly into a facial muscle before a nerve injury helped keep many more motor neurons alive than doing nothing. The study suggests that local, muscle‑origin IGF‑1 variants may protect nerves better than the usual liver‑produced IGF‑1 that circulates in the blood.
Abstract
We compared the neuroprotective effects of a liver-type isoform of insulin-like growth factor-I (IGF-IEa) and its splice variant, mechano-growth factor (MGF), isolated from active skeletal muscle. cDNAs of these peptides were injected into the facial muscle of adult rats prior to facial nerve avulsion. This resulted in significant neuroprotection of 88% and 37%, respectively, of motoneurons compared to control plasmid and avulsion-only groups. MGF is markedly more effective than the liver-type, systemic IGF-I for motoneuron survival, suggesting a major role for the peripheral target in adult neuronal maintenance and survival.
Study Information
pubmed
2004
2004-05-29T00:00:00.000Z
10.1016/j.brainres.2004.02.049
57
37