Insulin-like growth factor I gene expression is induced in astrocytes duringexperimental demyelination

The role of insulin-like growth factor I (IGF-I) in myelin regeneration was studied using cuprizone to produce demyelinating lesions in the brain areas of cuprizone-fed mice. The levels of IGF-I and its receptors were then examined atboth genetic and peptide levels. The results showed that IGF-I expression was induced in astrocytes located at the demyelinated lesions. This expression decreased during recovery. Furthermore, there was also an increase in oligodendroglial IGF-I receptor expression during early recovery. The results suggest that IGF-I functions as a diffusible element that stimulates oligodendroglial-mediated activity towards myelin regeneration.