Different levels of neuroprotection by two insulin-like growth factor-I splice variants.
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.
Aperghis
Michael
M
Department of Anatomy and Developmental Biology, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
Johnson
Ian P
IP
Cannon
John
J
Yang
Shi-Yu
SY
Goldspink
Geoffrey
G
D017398:Alternative Splicing; D000818:Animals; D002470:Cell Survival / Q000235:genetics; D005152:Facial Muscles / Q000166:cytology; D020220:Facial Nerve Injuries / Q000378:metabolism*; D007839:Functional Laterality / Q000502:physiology; D022761:Gene Transfer, Horizontal / Q000502:physiology; D007273:Injections, Intramuscular; D007334:Insulin-Like Growth Factor I / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008297:Male; D009046:Motor Neurons / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014162:Transfection / Q000379:methods
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D018995:Myosin Heavy Chains