IGF-I promotes peripheral nervous system myelination.
Insulin-like growth factor-I (IGF-I) promotes the proliferation and differentiation of Schwann cells (SC). We use SC/dorsal root ganglion neuron (DRG) cocultures to examine the effects of IGF-I on the interaction between axons and SC. As SC extend processes toward the axon in the presence of IGF-I, these processes attach to and ensheath axons. Continued IGF-I exposure leads to enhanced P0 expression and long-term myelination. No myelination occurs in the absence of IGF-I. These data imply that IGF-I is critical not only for SC attachment and ensheathment of axons but also for long-term myelination.
Cheng
H L
HL
Department of Neurology, University of Michigan, Ann Arbor 48109-0588, USA.
Russell
J W
JW
Feldman
E L
EL
D000818:Animals; D000831:Animals, Newborn; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D018993:Myelin P0 Protein / Q000096:biosynthesis / Q000235:genetics; D009186:Myelin Sheath / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D010525:Peripheral Nerves / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
D018993:Myelin P0 Protein; D007334:Insulin-Like Growth Factor I